LIM + lifters
sverker
11-14-2010, 08:38 PM
Hi everybody,
I'm planning for changing the imfamous intake gasket on my '97 Trans sport (the name for the Venture in Europe). Mine is loosing coolant slowly and although I don't know where it's leeking an oil analyze didn't show any signs of antifreeze in the oil so it's not going there. The engine is running perfectly fine without being rough at any rpm and no smoke so no signs of a bad head or head gasket. I've read the looong thread on changing LIM gasket and it has provided valuable information.
It's probably not that urgent to change the gasket but I rather do it when I can chose a time for it than risk getting stuck in the middle of nowhere with the family in the car.. The car has close to 140 000 km (87 000 miles) so it hasn't gone that far yet.
I also have a soft ticking noice which sounds like a lifter, it's only there when idling on cold engine. Since I'm doing the LIM gasket as I understand it the lifters will then also be accessible so it's probably a good idea to change them too. A question, should I change all or just try to find the ticking one? I think I'd go for changing all, 12 lifters (correct number?) is more than half of the total parts cost but it's more important to be able to complete the work without having to stop for ordering more parts and if one is ticking then probably soon another will too..
On my shopping list from rockauto is the FEL-PRO improved gasket kit MS98003T, don't know which of the other kits has the metal gasket.. New bolts will be used as well.
In addition I'm planning to change the following when on the job:
* spark plugs and wires
* thermostat
* radiator cap
* pcv valve
* fule injector o-rings (is it correct that it should be 12? The FEL-PRO kit of 4 rings says that 3 sets are needed for one car)
* radiator hoses
* oil pump seal
* serpentine belt (need to figure out if I have the 105 amp or 140 amp alternator)
* water pump was recently changed by prev owner so I'll skip that one
* oil & filter engine
* oil & filter transmission
Any other suggestions of things that should be done at the same time? Any special tools needed except the torque wrench?
When you changed your LIM gasket, anyone experienced problems to get it to seal? Did you apply silicone on all surfaces before applying the gasket?
/Sverker
I'm planning for changing the imfamous intake gasket on my '97 Trans sport (the name for the Venture in Europe). Mine is loosing coolant slowly and although I don't know where it's leeking an oil analyze didn't show any signs of antifreeze in the oil so it's not going there. The engine is running perfectly fine without being rough at any rpm and no smoke so no signs of a bad head or head gasket. I've read the looong thread on changing LIM gasket and it has provided valuable information.
It's probably not that urgent to change the gasket but I rather do it when I can chose a time for it than risk getting stuck in the middle of nowhere with the family in the car.. The car has close to 140 000 km (87 000 miles) so it hasn't gone that far yet.
I also have a soft ticking noice which sounds like a lifter, it's only there when idling on cold engine. Since I'm doing the LIM gasket as I understand it the lifters will then also be accessible so it's probably a good idea to change them too. A question, should I change all or just try to find the ticking one? I think I'd go for changing all, 12 lifters (correct number?) is more than half of the total parts cost but it's more important to be able to complete the work without having to stop for ordering more parts and if one is ticking then probably soon another will too..
On my shopping list from rockauto is the FEL-PRO improved gasket kit MS98003T, don't know which of the other kits has the metal gasket.. New bolts will be used as well.
In addition I'm planning to change the following when on the job:
* spark plugs and wires
* thermostat
* radiator cap
* pcv valve
* fule injector o-rings (is it correct that it should be 12? The FEL-PRO kit of 4 rings says that 3 sets are needed for one car)
* radiator hoses
* oil pump seal
* serpentine belt (need to figure out if I have the 105 amp or 140 amp alternator)
* water pump was recently changed by prev owner so I'll skip that one
* oil & filter engine
* oil & filter transmission
Any other suggestions of things that should be done at the same time? Any special tools needed except the torque wrench?
When you changed your LIM gasket, anyone experienced problems to get it to seal? Did you apply silicone on all surfaces before applying the gasket?
/Sverker
lesterl
11-14-2010, 09:38 PM
My LIM I used silicone on the valleys.
Your list looks good.
Might go for all the lifters, before you tear down, might run a quart of trans fluid thru the engine oil (have to loose a qt of oil first.)
Replace the LIM gasket ASAP. This is not a laughing matter, could cost you an engine if you wait too long.
Here in the USA the Transport is a Pontiac version of the Chevrolet Venture.
BTW, if you have rear AIR/HEAT it will usually have the 140 Amp Alternator, if you dont have the extra HVAC unit, it has the lower one.
Your list looks good.
Might go for all the lifters, before you tear down, might run a quart of trans fluid thru the engine oil (have to loose a qt of oil first.)
Replace the LIM gasket ASAP. This is not a laughing matter, could cost you an engine if you wait too long.
Here in the USA the Transport is a Pontiac version of the Chevrolet Venture.
BTW, if you have rear AIR/HEAT it will usually have the 140 Amp Alternator, if you dont have the extra HVAC unit, it has the lower one.
paprius4030
11-15-2010, 07:15 AM
Are you sure it's the lifters causing that noise. The Venture engine is know for what is called " I believe" piston ring slap. It sounds like a lifter going bad and it is ONLY when first started in the morning and goes away when the engine warms up. Both my 99 and 04 Venture makes that noise, I believe it's quite common and basically harmless. My 99 Venture did it for 205kmi. till I sold it. If you think that might be it, I wouldn't worry about it.
merc81
11-15-2010, 08:06 AM
You will need the crow's foot wrench (10mm) to remove and later reinstall the side bolts on the intake manifold. That's a short flat box wrench that connect at right angles to a socket shaft. Two of the LIM bolts are recessed under the edge of the casting and difficult to reach with this.
Also plan to clean out the EGR valve while you have it all apart.
Sounds like your considered the project pretty well.
Also plan to clean out the EGR valve while you have it all apart.
Sounds like your considered the project pretty well.
sverker
11-16-2010, 03:30 PM
Hi
good suggestions. In preparing for this task I've read more or less everything in this forum on the subject and it has been a great help. Since I'm not native English speeking I need to check a few details to make sure I understood all
Lesterl: How long do you suggest to run the engine with ATF oil? You write that you used silicon on "the valleys". Looking at http://www.d-tips.com/SpecialPhotos/34bord16.jpg (from http://www.d-tips.com/general/articles/article.aspx?id=2), which is also is the same as is shown in the Haynes manual, it looks like they only put silicon on this specific surface at both ends of the block. I.e. not on the surfaces where the gasket meets the block and the mainfold. Correct?
paprius4030: No, I'm not sure it's a lifter. I found a suggestion in Haynes now how to find out so I'll test that. There is also a description there on how to investigate if they are bad when taken out.
It's probably overkill to change all as it's most likely only one that may be stuck, but on the other hand they are not very expensive.. I'll think a bit more on that one.. I can buy lifters here in Sweden, but it cost more for only the lifters than buying all the needed parts for this job from rockauto including the lifers, shipping and taxes...
merc81: crow's foot wrench, is that this one? http://www.jula.se/nyckelset-krakfotter-10-delar-124395
Yes, sounds like a good idea to also clean the EGR. I don't have the rear heater so I probably have the 105A alternator which is unusual here. (thinking about moving over the rear heater and vents from a spare part car)
One more thing, I've noticed sometimes that in the speed around 75 km/h (~ 45 mph) then the tranny want to switch too early to the higher gear which gives some protests. If I accelerate then it switch down gently and then at higher speed again to the higher gear without problem. That is the only time it happens, not at other speeds. As I understand it it's a 4T60 in my '97 and then according to Haynes there is a vacum thing that could cause that behaviour. Thoughts? It's time to give it new filter and oil anyway.
good suggestions. In preparing for this task I've read more or less everything in this forum on the subject and it has been a great help. Since I'm not native English speeking I need to check a few details to make sure I understood all
Lesterl: How long do you suggest to run the engine with ATF oil? You write that you used silicon on "the valleys". Looking at http://www.d-tips.com/SpecialPhotos/34bord16.jpg (from http://www.d-tips.com/general/articles/article.aspx?id=2), which is also is the same as is shown in the Haynes manual, it looks like they only put silicon on this specific surface at both ends of the block. I.e. not on the surfaces where the gasket meets the block and the mainfold. Correct?
paprius4030: No, I'm not sure it's a lifter. I found a suggestion in Haynes now how to find out so I'll test that. There is also a description there on how to investigate if they are bad when taken out.
It's probably overkill to change all as it's most likely only one that may be stuck, but on the other hand they are not very expensive.. I'll think a bit more on that one.. I can buy lifters here in Sweden, but it cost more for only the lifters than buying all the needed parts for this job from rockauto including the lifers, shipping and taxes...
merc81: crow's foot wrench, is that this one? http://www.jula.se/nyckelset-krakfotter-10-delar-124395
Yes, sounds like a good idea to also clean the EGR. I don't have the rear heater so I probably have the 105A alternator which is unusual here. (thinking about moving over the rear heater and vents from a spare part car)
One more thing, I've noticed sometimes that in the speed around 75 km/h (~ 45 mph) then the tranny want to switch too early to the higher gear which gives some protests. If I accelerate then it switch down gently and then at higher speed again to the higher gear without problem. That is the only time it happens, not at other speeds. As I understand it it's a 4T60 in my '97 and then according to Haynes there is a vacum thing that could cause that behaviour. Thoughts? It's time to give it new filter and oil anyway.
lesterl
11-16-2010, 09:02 PM
Good links for the repair, looks like you may need a new vac modulator for the transmission, mine is an adjustable unit....
merc81
11-17-2010, 10:37 AM
Yes, that's the type of wrench you will need. Try to borrow one as they only come in a set here and cost $$$. I've never really needed one before this job, but I have done this three times before and I snapped one of the bolts once because I wasn't using that crow's foot wrench.
sverker
11-17-2010, 10:54 AM
The set that I linked to is just $20 so that's one of the least problems on this job.. ;)
merc81
11-17-2010, 11:20 AM
I've also kicked myself later for not having changed out those small coolant hosts and the O ring under the throttle assembly. Its impossible to change while assembled and those hoses fail around 120k miles or so. I had to go back and change them and it wasn't fun.
The rtv sealant comes with the kit from rockauto. Its only used at the ends as you say and the link you posted looks exactly like what the job should look like when done.
The rtv sealant comes with the kit from rockauto. Its only used at the ends as you say and the link you posted looks exactly like what the job should look like when done.
sverker
11-17-2010, 04:46 PM
What o-ring under throttle assembly? I can't find which that is on rockauto. I've already added the o-rings for the injectors to the list.
Is the rtv sealant tube that's included with the kit big enough or do I need to get some extra?
Is the rtv sealant tube that's included with the kit big enough or do I need to get some extra?
lesterl
11-17-2010, 08:10 PM
My Felpro Permadry Plus kit came with a small tube and it was BARELY enough..... Never hurts to have some RTV around IMHO......
merc81
11-18-2010, 08:24 AM
The O ring I mentioned would not be in any kit for the LIM repair. Its the O ring that seals the coolant line that runs from the manifold under the throttle assembly and out to the heater.
http://cemrweb.cemr.wvu.edu/~mathews/venture/coolant-0-ring.png
Look to the right side in the photo. The black pipe exiting the manifold uses an O ring to seal and you should replace that while you're in there.
Below are the two intake lines that should be changed:
http://cemrweb.cemr.wvu.edu/~mathews/venture/intake-coolant.png
http://cemrweb.cemr.wvu.edu/~mathews/venture/coolant-0-ring.png
Look to the right side in the photo. The black pipe exiting the manifold uses an O ring to seal and you should replace that while you're in there.
Below are the two intake lines that should be changed:
http://cemrweb.cemr.wvu.edu/~mathews/venture/intake-coolant.png
sverker
11-18-2010, 09:30 AM
Ok, do you know part numbers or what they are called on Rockauto?
I've already added something called Thermostat Housing Gasket FEL-PRO Part #70799. There is something they call Thermostat Seal but the thermostat is including that.
There is also something called Water Outlet Gasket FEL-PRO Part #35614, could that be the one?
Do you have any suggestion of part number for the hoses? The left one looks like a straight so then an universal hose would do but the right one looks curved.
I've already added something called Thermostat Housing Gasket FEL-PRO Part #70799. There is something they call Thermostat Seal but the thermostat is including that.
There is also something called Water Outlet Gasket FEL-PRO Part #35614, could that be the one?
Do you have any suggestion of part number for the hoses? The left one looks like a straight so then an universal hose would do but the right one looks curved.
merc81
11-18-2010, 09:53 AM
I found the right angle hose on rockauto's site via a photo. Because I purchased half a dozen hoses at the same time (see my post over on the silhouette forum about hoses) I can't say what the part number was, but the photo was accurate.
The water outlet gasket sounds like it could be correct, but I didn't purchase that one--I had one that fit from a freon replacement seal kit. It has nothing to do with the thermostat however.
The water outlet gasket sounds like it could be correct, but I didn't purchase that one--I had one that fit from a freon replacement seal kit. It has nothing to do with the thermostat however.
sverker
11-19-2010, 06:21 AM
Hi,
found it. It's the hoses for throttle house pre-heat which connects to by-pass line. I'm changing the hose in the other end of that one as well, just a few dollars.
found it. It's the hoses for throttle house pre-heat which connects to by-pass line. I'm changing the hose in the other end of that one as well, just a few dollars.
sverker
11-19-2010, 04:50 PM
Is there anything that require access from under the engine on this job? I won't have access to lift, but I could use ramps.
lesterl
11-19-2010, 07:26 PM
Changing the Oil when done.....
sverker
11-20-2010, 04:30 PM
Yes, definitly...
I've made the order to rockauto now, will be interesting to see how long time it takes to ship but other peoples experience is that rockauto is faster to get the parts to Sweden than the local dealer is to deliver...
I've made the order to rockauto now, will be interesting to see how long time it takes to ship but other peoples experience is that rockauto is faster to get the parts to Sweden than the local dealer is to deliver...
sverker
06-13-2011, 06:46 PM
Hi again,
I've finally got started on doing this job. In another thread I described that I got an oil leak (http://www.automotiveforums.com/vbulletin/showthread.php?p=6886466), haven't driven it since except for moving it from one parkinglot to another recently (roughly 200 meters). When I parked it I checked the oil and this time it was clear that there was water in the oil so the LIM gasket had finaly broken.
Tonight I've been taking the engine apart to get to the LIM which took roughly 4 hours taking it slow and marking all cables and hosed. All went fine, except for one incident:
http://www.abrahamsson.com/IMAG0085.jpg
One of the bolts for the thermostat had stuck in the gradients and cracked it :(. What do you suggest, repare it (weld up new material and drill a new hole which is difficult but not impossible on aluminium) or try to find a new LIM at the junk yard?
I also saw a strange thing:
http://www.abrahamsson.com/IMAG0079.jpg
This box is connected to the harness that goes to the injectors. I'm pretty sure it's purpose is to lengthen the injector is open to allow the engine to run on E85 (85% ethanol, 15% gasoline). That must have been installed by previous owner and not from factory? There is a jumper cable behind the box, I think that should have gone to a switch on the dashboard to switch on/off E85 mode, but maybe the injector controler is able to regulate it anyway.
I've finally got started on doing this job. In another thread I described that I got an oil leak (http://www.automotiveforums.com/vbulletin/showthread.php?p=6886466), haven't driven it since except for moving it from one parkinglot to another recently (roughly 200 meters). When I parked it I checked the oil and this time it was clear that there was water in the oil so the LIM gasket had finaly broken.
Tonight I've been taking the engine apart to get to the LIM which took roughly 4 hours taking it slow and marking all cables and hosed. All went fine, except for one incident:
http://www.abrahamsson.com/IMAG0085.jpg
One of the bolts for the thermostat had stuck in the gradients and cracked it :(. What do you suggest, repare it (weld up new material and drill a new hole which is difficult but not impossible on aluminium) or try to find a new LIM at the junk yard?
I also saw a strange thing:
http://www.abrahamsson.com/IMAG0079.jpg
This box is connected to the harness that goes to the injectors. I'm pretty sure it's purpose is to lengthen the injector is open to allow the engine to run on E85 (85% ethanol, 15% gasoline). That must have been installed by previous owner and not from factory? There is a jumper cable behind the box, I think that should have gone to a switch on the dashboard to switch on/off E85 mode, but maybe the injector controler is able to regulate it anyway.
lesterl
06-14-2011, 10:05 PM
Pix are WAYYYYY to large.......
New LIM from a J/Y.......
Could be a propane controller? IDK
New LIM from a J/Y.......
Could be a propane controller? IDK
sverker
06-15-2011, 07:20 AM
Pictures re-scaled to a more sane size..
We have an online system for the junk yards where they list the parts, the problem is that there is no category for the intake and none list it neither in the misc category. There are plenty of other parts from these engines so they have taken apart severals.
I'm trying to find the part number of the intake, to be able to find also if there are other engines that have the same intake. As I understand it that part was changed sometime mid -99, the laters doesn't have hole for temperature sensor in the thermostat house and slightly different channels for the coolant.
Regarding the device (multiport injector interceptor), I've mailed to the manufacturer but I'm quite sure it's related to runnign on ethanol, since propane (also called LPG here) require other hardware as well.
We have an online system for the junk yards where they list the parts, the problem is that there is no category for the intake and none list it neither in the misc category. There are plenty of other parts from these engines so they have taken apart severals.
I'm trying to find the part number of the intake, to be able to find also if there are other engines that have the same intake. As I understand it that part was changed sometime mid -99, the laters doesn't have hole for temperature sensor in the thermostat house and slightly different channels for the coolant.
Regarding the device (multiport injector interceptor), I've mailed to the manufacturer but I'm quite sure it's related to runnign on ethanol, since propane (also called LPG here) require other hardware as well.
sverker
07-21-2011, 07:48 PM
Hi again,
I've now driven roughly 70 miles after the LIM gasket change and so far I have not seen that it's loosing coolant and the oil looks good. Neither has any mechanical rattling developed.
Today I went to do the mandatory yearly check which also includes emission tests. They do the test at idling and at 2500 rpm to check various parameters, it got too high values on CO and HC on idling. CO was 1.5% (allowed 0.5&), HC was 367 ppm (allowed 100 ppm). Also CO at 2500 rpm was just at the limit 0.3%. The lambda value was 1.01 (which is a calculated value, not actually measured). As earlier mentioned the ODB reading gives code P0134 which is that the front O2 sensor is not working so I was not very supprised. The rear shock absorbers were also bad, which I had been feeling. The air lines was completly dried out and broken so I'll give it a try to replace them which has to be done anyway.
When driving to the test center I felt at speeds between roughly 90 and 100 km/h (approx 55 - 60 mph) some shoudering. It was like driving on a too high gear, I've felt it before when driving last summer at some occations. I then spontaneously diagnosed it as a tranny / torque converter issue and searching the forum today I find that it might be true as people describe that symptom when the torque converter lookup is malfunctioning. The tranny is shifting gears smothly, no hard shifting has been noticed. Accelerating up to 110 km/h removed the shoudering at that time. It was more of a feeling, the rpm of the tachometer did not fluctuate.
After finishing the tests and driving from the center I saw the temperature gauge reading higher than usual, it's usually at the middle at 100 degrees and now it was at 2/3, and the fans still didn't run. I verified yesterday that the fans themselves and their relays work fine. After driving for a few minutes the temperature had returned to the norma. When searching the forum I find that this might not be a fault after all as the temperature might not have been high enough for the fans to kick in.
When driving back it was raining and very humid. Then I experienced shoudering also at lower speeds, and it was very prone to stalling when releasing the accelerator to slow down at red lights. It's hard to tell if it was the torque converter lockup causing the problems, at some times it felt like that, or if it is sensitive to humidity for some reason. I plugged in my bluetooth ODB-II adapter but no new codes had been recorded. When I came home I let it idle for a while, maybe it was slightly uneven but very little and it couldn't be seen on the tachometer. At a short drive tonight when it's not raining I didn't feel any uneven operation.
The plan for next steps are as follows:
* There is a hose from the back valve cover to the air intake which is not perfectly seated in the valve cover. It's darn hard to reach but it will need to get in place properly. The engine would suck air that way otherwise.
* Verify that there are no vacuum leeks.
* Clean the MAF sensor, I read here on the forum that it may sometimes cause the O2 sensor code to appear. Doesn't hurt to try it.
* If the above doesn't solve the issue then change the O2 sensor. Spark plugs and wires are new, the old plugs looked normal so the high HC value is not caused by oil leaking into the cylinder (which also would cause it to be smoking).
* Check the actual engine temperature through ODB-II, to see if it becomes hot enough for the fans to kick in. I'm not sure if I can use the AC trick to make them start as my system is completly depresurized. If the engine do become hot enough then verify the wires to the PCM.
Btw, as it looks on the electrical circuit drawings it seems the PCM outputs are pull down. I.e. they operate by pulling the signal to the ground and doesn't have an active pull up. Is this true? If so then the signals can be externaly grounded to test the function without risking to fry the PCM.
* Change filter and fluid in the tranny, it's due anyway. Mine should be an 4T60-E if I understand correctly. As I understand the solution is to change the TCC solenoid and torque converter seal but that the tranny would have to be dropped to do that. The latter is not a major obstactle, a good friend of mine runs a workshop which among other things does automatic transmissions.
Any other suggestions to investigate for the above described symptoms? Idle air control valve? Air intake temperature sensor? MAP sensor? Fuel filter?
I've now driven roughly 70 miles after the LIM gasket change and so far I have not seen that it's loosing coolant and the oil looks good. Neither has any mechanical rattling developed.
Today I went to do the mandatory yearly check which also includes emission tests. They do the test at idling and at 2500 rpm to check various parameters, it got too high values on CO and HC on idling. CO was 1.5% (allowed 0.5&), HC was 367 ppm (allowed 100 ppm). Also CO at 2500 rpm was just at the limit 0.3%. The lambda value was 1.01 (which is a calculated value, not actually measured). As earlier mentioned the ODB reading gives code P0134 which is that the front O2 sensor is not working so I was not very supprised. The rear shock absorbers were also bad, which I had been feeling. The air lines was completly dried out and broken so I'll give it a try to replace them which has to be done anyway.
When driving to the test center I felt at speeds between roughly 90 and 100 km/h (approx 55 - 60 mph) some shoudering. It was like driving on a too high gear, I've felt it before when driving last summer at some occations. I then spontaneously diagnosed it as a tranny / torque converter issue and searching the forum today I find that it might be true as people describe that symptom when the torque converter lookup is malfunctioning. The tranny is shifting gears smothly, no hard shifting has been noticed. Accelerating up to 110 km/h removed the shoudering at that time. It was more of a feeling, the rpm of the tachometer did not fluctuate.
After finishing the tests and driving from the center I saw the temperature gauge reading higher than usual, it's usually at the middle at 100 degrees and now it was at 2/3, and the fans still didn't run. I verified yesterday that the fans themselves and their relays work fine. After driving for a few minutes the temperature had returned to the norma. When searching the forum I find that this might not be a fault after all as the temperature might not have been high enough for the fans to kick in.
When driving back it was raining and very humid. Then I experienced shoudering also at lower speeds, and it was very prone to stalling when releasing the accelerator to slow down at red lights. It's hard to tell if it was the torque converter lockup causing the problems, at some times it felt like that, or if it is sensitive to humidity for some reason. I plugged in my bluetooth ODB-II adapter but no new codes had been recorded. When I came home I let it idle for a while, maybe it was slightly uneven but very little and it couldn't be seen on the tachometer. At a short drive tonight when it's not raining I didn't feel any uneven operation.
The plan for next steps are as follows:
* There is a hose from the back valve cover to the air intake which is not perfectly seated in the valve cover. It's darn hard to reach but it will need to get in place properly. The engine would suck air that way otherwise.
* Verify that there are no vacuum leeks.
* Clean the MAF sensor, I read here on the forum that it may sometimes cause the O2 sensor code to appear. Doesn't hurt to try it.
* If the above doesn't solve the issue then change the O2 sensor. Spark plugs and wires are new, the old plugs looked normal so the high HC value is not caused by oil leaking into the cylinder (which also would cause it to be smoking).
* Check the actual engine temperature through ODB-II, to see if it becomes hot enough for the fans to kick in. I'm not sure if I can use the AC trick to make them start as my system is completly depresurized. If the engine do become hot enough then verify the wires to the PCM.
Btw, as it looks on the electrical circuit drawings it seems the PCM outputs are pull down. I.e. they operate by pulling the signal to the ground and doesn't have an active pull up. Is this true? If so then the signals can be externaly grounded to test the function without risking to fry the PCM.
* Change filter and fluid in the tranny, it's due anyway. Mine should be an 4T60-E if I understand correctly. As I understand the solution is to change the TCC solenoid and torque converter seal but that the tranny would have to be dropped to do that. The latter is not a major obstactle, a good friend of mine runs a workshop which among other things does automatic transmissions.
Any other suggestions to investigate for the above described symptoms? Idle air control valve? Air intake temperature sensor? MAP sensor? Fuel filter?
lesterl
07-21-2011, 11:53 PM
Hi again,
I've now driven roughly 70 miles after the LIM gasket change and so far I have not seen that it's loosing coolant and the oil looks good. Neither has any mechanical rattling developed.
Today I went to do the mandatory yearly check which also includes emission tests. They do the test at idling and at 2500 rpm to check various parameters, it got too high values on CO and HC on idling. CO was 1.5% (allowed 0.5&), HC was 367 ppm (allowed 100 ppm). Also CO at 2500 rpm was just at the limit 0.3%. The lambda value was 1.01 (which is a calculated value, not actually measured). As earlier mentioned the ODB reading gives code P0134 which is that the front O2 sensor is not working so I was not very supprised. The rear shock absorbers were also bad, which I had been feeling. The air lines was completly dried out and broken so I'll give it a try to replace them which has to be done anyway.
When driving to the test center I felt at speeds between roughly 90 and 100 km/h (approx 55 - 60 mph) some shoudering. It was like driving on a too high gear, I've felt it before when driving last summer at some occations. I then spontaneously diagnosed it as a tranny / torque converter issue and searching the forum today I find that it might be true as people describe that symptom when the torque converter lookup is malfunctioning. The tranny is shifting gears smothly, no hard shifting has been noticed. Accelerating up to 110 km/h removed the shoudering at that time. It was more of a feeling, the rpm of the tachometer did not fluctuate.
After finishing the tests and driving from the center I saw the temperature gauge reading higher than usual, it's usually at the middle at 100 degrees and now it was at 2/3, and the fans still didn't run. I verified yesterday that the fans themselves and their relays work fine. After driving for a few minutes the temperature had returned to the norma. When searching the forum I find that this might not be a fault after all as the temperature might not have been high enough for the fans to kick in.
When driving back it was raining and very humid. Then I experienced shoudering also at lower speeds, and it was very prone to stalling when releasing the accelerator to slow down at red lights. It's hard to tell if it was the torque converter lockup causing the problems, at some times it felt like that, or if it is sensitive to humidity for some reason. I plugged in my bluetooth ODB-II adapter but no new codes had been recorded. When I came home I let it idle for a while, maybe it was slightly uneven but very little and it couldn't be seen on the tachometer. At a short drive tonight when it's not raining I didn't feel any uneven operation.
The plan for next steps are as follows:
* There is a hose from the back valve cover to the air intake which is not perfectly seated in the valve cover. It's darn hard to reach but it will need to get in place properly. The engine would suck air that way otherwise.
Definitely.
* Verify that there are no vacuum leeks.
Definitely.
* Clean the MAF sensor, I read here on the forum that it may sometimes cause the O2 sensor code to appear. Doesn't hurt to try it.
Wouldnt Hurt.
* If the above doesn't solve the issue then change the O2 sensor. Spark plugs and wires are new, the old plugs looked normal so the high HC value is not caused by oil leaking into the cylinder (which also would cause it to be smoking).
What brand of spark plugs? I did some Bosch, junk, ended up with some NGK's and it runs very smooth now. Might need to clean the sensor.......
* Check the actual engine temperature through ODB-II, to see if it becomes hot enough for the fans to kick in. I'm not sure if I can use the AC trick to make them start as my system is completly depresurized. If the engine do become hot enough then verify the wires to the PCM.
Fans kick in at around 235* on mine (3/4 scale).... Comes on sooner with AC on IIRC.......
Btw, as it looks on the electrical circuit drawings it seems the PCM outputs are pull down. I.e. they operate by pulling the signal to the ground and doesn't have an active pull up. Is this true? If so then the signals can be externaly grounded to test the function without risking to fry the PCM.
AFAIK that is correct......
* Change filter and fluid in the tranny, it's due anyway. Mine should be an 4T60-E if I understand correctly. As I understand the solution is to change the TCC solenoid and torque converter seal but that the tranny would have to be dropped to do that. The latter is not a major obstactle, a good friend of mine runs a workshop which among other things does automatic transmissions.
Yup 4T60e, same as mine (97 Venture), might have a worn valve body also.......
Any other suggestions to investigate for the above described symptoms? Idle air control valve? Air intake temperature sensor? MAP sensor? Fuel filter?
Doubt it, Doubt it, Doubt it, You havent changed the fuel filter lately?
I've now driven roughly 70 miles after the LIM gasket change and so far I have not seen that it's loosing coolant and the oil looks good. Neither has any mechanical rattling developed.
Today I went to do the mandatory yearly check which also includes emission tests. They do the test at idling and at 2500 rpm to check various parameters, it got too high values on CO and HC on idling. CO was 1.5% (allowed 0.5&), HC was 367 ppm (allowed 100 ppm). Also CO at 2500 rpm was just at the limit 0.3%. The lambda value was 1.01 (which is a calculated value, not actually measured). As earlier mentioned the ODB reading gives code P0134 which is that the front O2 sensor is not working so I was not very supprised. The rear shock absorbers were also bad, which I had been feeling. The air lines was completly dried out and broken so I'll give it a try to replace them which has to be done anyway.
When driving to the test center I felt at speeds between roughly 90 and 100 km/h (approx 55 - 60 mph) some shoudering. It was like driving on a too high gear, I've felt it before when driving last summer at some occations. I then spontaneously diagnosed it as a tranny / torque converter issue and searching the forum today I find that it might be true as people describe that symptom when the torque converter lookup is malfunctioning. The tranny is shifting gears smothly, no hard shifting has been noticed. Accelerating up to 110 km/h removed the shoudering at that time. It was more of a feeling, the rpm of the tachometer did not fluctuate.
After finishing the tests and driving from the center I saw the temperature gauge reading higher than usual, it's usually at the middle at 100 degrees and now it was at 2/3, and the fans still didn't run. I verified yesterday that the fans themselves and their relays work fine. After driving for a few minutes the temperature had returned to the norma. When searching the forum I find that this might not be a fault after all as the temperature might not have been high enough for the fans to kick in.
When driving back it was raining and very humid. Then I experienced shoudering also at lower speeds, and it was very prone to stalling when releasing the accelerator to slow down at red lights. It's hard to tell if it was the torque converter lockup causing the problems, at some times it felt like that, or if it is sensitive to humidity for some reason. I plugged in my bluetooth ODB-II adapter but no new codes had been recorded. When I came home I let it idle for a while, maybe it was slightly uneven but very little and it couldn't be seen on the tachometer. At a short drive tonight when it's not raining I didn't feel any uneven operation.
The plan for next steps are as follows:
* There is a hose from the back valve cover to the air intake which is not perfectly seated in the valve cover. It's darn hard to reach but it will need to get in place properly. The engine would suck air that way otherwise.
Definitely.
* Verify that there are no vacuum leeks.
Definitely.
* Clean the MAF sensor, I read here on the forum that it may sometimes cause the O2 sensor code to appear. Doesn't hurt to try it.
Wouldnt Hurt.
* If the above doesn't solve the issue then change the O2 sensor. Spark plugs and wires are new, the old plugs looked normal so the high HC value is not caused by oil leaking into the cylinder (which also would cause it to be smoking).
What brand of spark plugs? I did some Bosch, junk, ended up with some NGK's and it runs very smooth now. Might need to clean the sensor.......
* Check the actual engine temperature through ODB-II, to see if it becomes hot enough for the fans to kick in. I'm not sure if I can use the AC trick to make them start as my system is completly depresurized. If the engine do become hot enough then verify the wires to the PCM.
Fans kick in at around 235* on mine (3/4 scale).... Comes on sooner with AC on IIRC.......
Btw, as it looks on the electrical circuit drawings it seems the PCM outputs are pull down. I.e. they operate by pulling the signal to the ground and doesn't have an active pull up. Is this true? If so then the signals can be externaly grounded to test the function without risking to fry the PCM.
AFAIK that is correct......
* Change filter and fluid in the tranny, it's due anyway. Mine should be an 4T60-E if I understand correctly. As I understand the solution is to change the TCC solenoid and torque converter seal but that the tranny would have to be dropped to do that. The latter is not a major obstactle, a good friend of mine runs a workshop which among other things does automatic transmissions.
Yup 4T60e, same as mine (97 Venture), might have a worn valve body also.......
Any other suggestions to investigate for the above described symptoms? Idle air control valve? Air intake temperature sensor? MAP sensor? Fuel filter?
Doubt it, Doubt it, Doubt it, You havent changed the fuel filter lately?
sverker
07-23-2011, 05:57 PM
* If the above doesn't solve the issue then change the O2 sensor. Spark plugs and wires are new, the old plugs looked normal so the high HC value is not caused by oil leaking into the cylinder (which also would cause it to be smoking).
What brand of spark plugs? I did some Bosch, junk, ended up with some NGK's and it runs very smooth now. Might need to clean the sensor.......
I see on the list from Rockauto that the new spark plugs that I ordered are Champion. The wire set are from Standard Motor Products
* Check the actual engine temperature through ODB-II, to see if it becomes hot enough for the fans to kick in. I'm not sure if I can use the AC trick to make them start as my system is completly depresurized. If the engine do become hot enough then verify the wires to the PCM.
Fans kick in at around 235* on mine (3/4 scale).... Comes on sooner with AC on IIRC.......
When driving in the city today the temperature gauge came up to about 3/4 so I was getting worried but then I could see it was moving down again to about 1/2 so the fans must have started. I couldn't stop in middle of traffic to verify it visually though.
Any other suggestions to investigate for the above described symptoms? Idle air control valve? Air intake temperature sensor? MAP sensor? Fuel filter?
Doubt it, Doubt it, Doubt it, You havent changed the fuel filter lately?
I haven't changed the fuel filter at all, so it's definitly something to put on the todo list.
Today the engined stalled on several occations when driving in the city, always when releasing the accelerator to slow down to a red light. It didn't help to put the gear in neutral, the tachometer started to move up and down like it almost died then came back and died again. By manually keeping a slightly higher idle rpm with the accelerator I could keep it from dying.
That rules out that this problem is related to the torque converter as it occured even if the gear was in N. Neither was it raining today so humidity is not a factor. It only happens on warm engine, the temp gauge was between 1/2 and 3/4.
What brand of spark plugs? I did some Bosch, junk, ended up with some NGK's and it runs very smooth now. Might need to clean the sensor.......
I see on the list from Rockauto that the new spark plugs that I ordered are Champion. The wire set are from Standard Motor Products
* Check the actual engine temperature through ODB-II, to see if it becomes hot enough for the fans to kick in. I'm not sure if I can use the AC trick to make them start as my system is completly depresurized. If the engine do become hot enough then verify the wires to the PCM.
Fans kick in at around 235* on mine (3/4 scale).... Comes on sooner with AC on IIRC.......
When driving in the city today the temperature gauge came up to about 3/4 so I was getting worried but then I could see it was moving down again to about 1/2 so the fans must have started. I couldn't stop in middle of traffic to verify it visually though.
Any other suggestions to investigate for the above described symptoms? Idle air control valve? Air intake temperature sensor? MAP sensor? Fuel filter?
Doubt it, Doubt it, Doubt it, You havent changed the fuel filter lately?
I haven't changed the fuel filter at all, so it's definitly something to put on the todo list.
Today the engined stalled on several occations when driving in the city, always when releasing the accelerator to slow down to a red light. It didn't help to put the gear in neutral, the tachometer started to move up and down like it almost died then came back and died again. By manually keeping a slightly higher idle rpm with the accelerator I could keep it from dying.
That rules out that this problem is related to the torque converter as it occured even if the gear was in N. Neither was it raining today so humidity is not a factor. It only happens on warm engine, the temp gauge was between 1/2 and 3/4.
lesterl
07-23-2011, 08:21 PM
Check the fuel pressure, change the filter, check again. Might check/ clean the IAC valve as well as the EGR, the EGR not closing off after a slow down could cause your issue, or perhaps unplug it before you start it so it stays closed (will set a light sooner or later.)
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