98 just replace intake manifold gasket, now rough idle/stalling
plumbly
03-23-2005, 01:51 PM
I just had the intake manifold gasket replaced (150,000 miles) due to a slow coolant leak into the oil. $900+... and "no guarentee" that it won't still have some problems. The suggestion was to plan to "get rid of it" within 3-6 months.
Anyway, it was running fine for the last week weekafter I got it back, and Monday the check/service engine light came on, it started running rough and stalled. I turned around and came home (~1/2 mile) and parked it. Since I had just refuelled on Sunday, I thought perhaps it was "bad" gas, and dumped in some dry gas this morning. Now, it's running smoother, but now stalls when idling. Any ideas before I take it back again for service?
Thanks in advance!
Anyway, it was running fine for the last week weekafter I got it back, and Monday the check/service engine light came on, it started running rough and stalled. I turned around and came home (~1/2 mile) and parked it. Since I had just refuelled on Sunday, I thought perhaps it was "bad" gas, and dumped in some dry gas this morning. Now, it's running smoother, but now stalls when idling. Any ideas before I take it back again for service?
Thanks in advance!
Milo2001
03-25-2005, 11:17 AM
If the check engine light came on, have someone pull the engine codes to see there are any problems. Could be a clogged fuel filter or your fuel pump is getting ready to quit.
94 Jimmy
04-12-2005, 03:26 PM
Are you sure it wasn't a head gasket? To have gotten all the way to the lower intake manifold and not done the heads is a shame. I just got mine off the jacks last night, the front head gasket had turned to mush. I changed it 50K Mi ago at 100 K Mi, I'll never use Fel-Pro again, this is the second time I had one of their gaskets fail.
Also if you were getting anti freeze into the combustion chamber that could kill your O2 Sensor and possibly cause you to run rich/lean.
If you like keeping up on the condition of your car get an OBDII reader, you can get mulitformat units that run on a PC, Laptop or even a PDA for around $100, get together with some friends and get one, it's the only way to go. Check out http://www.scantool.net/ .
Good luck
94
Also if you were getting anti freeze into the combustion chamber that could kill your O2 Sensor and possibly cause you to run rich/lean.
If you like keeping up on the condition of your car get an OBDII reader, you can get mulitformat units that run on a PC, Laptop or even a PDA for around $100, get together with some friends and get one, it's the only way to go. Check out http://www.scantool.net/ .
Good luck
94
redly1
04-15-2005, 02:23 PM
I just had my intake manifold gasket done on my 03 Montana. I experinced the rouch idle condition, accompanied by a "vacuum leak" type noise and check engine light.
Ended up being that they broke an o-ring on one of the fuel injectors. They replaced them all and now it runs fine
Ended up being that they broke an o-ring on one of the fuel injectors. They replaced them all and now it runs fine
plumbly
05-10-2005, 07:58 AM
Seems there was a vacuum problem and they needed to replace yet again another part... I don't recall the name this time (female and blond :) ). Anyway it seems to be running fine now, althoug I'm leary of it now, shich is a shame as I have LOVED this van... for all 150,000+ miles! Guess it's really time to replace it with something else... not sure I need/want a van this time...
matredd
07-15-2005, 09:37 AM
We've got a 1998 Silhouette that started overheating quickly and the first cylinder was misfiring. Several people looked at it and all said different things. Some said it was the intake manifold gasket, the radiator's clogged (there was melted hose running through the system). The guy we actually got to fix it replaced the head gasket and did a valve job so it was running fine but still getting a little warm. It definitely wasn't getting hot quickly but warmer than normal. Once it would get about 3/4 of the way giving it gas would lower it to half or lower (I think it's the water pump forcing more though). There also was a point soon after we got the head gasket replaced where they had forgotten to release the pressure and a hose busted above the oil filter and was shooting out coolant. We replaced that and then it overheated again and the mechanic that replaced the head gasket towed it back to his shop and came to the conclusion that there wasn't enough coolant in there and that the thermostat was fine. I added plenty before and now it's still overheating. We ordered a new radiator today and will put it in tomorrow. I also hear a hissing noise when after the van has been driven around coming from the right side of the motor but not sure what it is. This is kinda long and confusing but if anyone has any suggestions that would be awesome.
cdru
07-15-2005, 11:45 AM
It definitely wasn't getting hot quickly but warmer than normal. Once it would get about 3/4 of the way giving it gas would lower it to half or lower (I think it's the water pump forcing more though).Normal opening tempature of the thermostat is 195. Presuming that your 98 uses the same gauge that my 98 Trans Sport does, this corresponds to right around the first major tick mark on the gauge. Normal driving should keep the tempature right about here. Stop and go city driving reduced the natural airflow around the radiator so the tempature will start to climb. How quickly depends on the ambient air tempature and how much air does get blown through the radiator.
The low speed fan kicks on at 220 which is approximately vertical or the 2nd major tick mark. The high speed fan kicks on at 230 degrees which is about 2 minor ticks after vertical.
Since doing my heads earlier this spring, I pay more attention to the coolant needle, partially out of fear I guess. I never noticed it swinging from one tempature to another before I started having problems, but I do now and feel that it's just normal operation.
There also was a point soon after we got the head gasket replaced where they had forgotten to release the pressure and a hose busted above the oil filter and was shooting out coolant. We replaced that and then it overheated again and the mechanic that replaced the head gasket towed it back to his shop and came to the conclusion that there wasn't enough coolant in there and that the thermostat was fine. I added plenty before and now it's still overheating. We ordered a new radiator today and will put it in tomorrow.How hot is is overheating? Approximately where is it at on the gauge? There could be several things that are wrong. The big thing would be was the system properly bled of air? If it wasn't, many of the symptoms you described could happen due to air pockets.
Our vans are difficult to quickly remove all the air in a single setting if you don't have the proper equipment. The best way is to pull a vacuum on the entire system, then suck in the coolant. But many shops don't have that equipment and instead just open the bleeder valves to get as much as they can and figure that is good enough. And it is for the most part but it will take 4 or 5 complete cycles to properly remove most of the air from everywhere.
Are you losing a noticable amount of coolant? If you are having to add any coolant on a regular basis, then you do have a leak somewhere. But if your resevoir has stayed at the same level, then you aren't losing coolant.
Another thing to check is make sure your radiator cap is working correctly. If it's broken or corroded, it may not allow the pressure to build up, excess pressure released, or vacuum to draw coolant back in.
Pressure is required to get up to 13 or 14PSIs to allow better heat retention as well as boilover protection. Each PSI over atmosphere allows 3 additional degrees of boil over protection. If the pressure doesn't build up, then you lose that boilover protection. 14PSIs gives you 42 additional degrees. That's signifiacnt.
If the pressure gets to high, the cap opens and coolant (or air) is allowed to flow into the overflow tank. On a freshly flushed system, as the engine heats up, any air in the system will also heat up, usually surpassing the 14 PSI opening pressure of the cap. This air then leaks out and bubbles through the coolant in the overflow tank. Then, when the system cools, any remaining are contracts, pulling a vacuum. A different valve opens in the cap allowing coolant to be drawn back in to replace where that air was at that was displaced.
This process repeats several times to get the system properly bled. If the cap isn't working correctly, it's possible for coolant to be pushed out but not back, which caused colapsed hoses. If the coolant and air can't be released, then pressure can build up and burst a hose.
Finally, after a hard drive check to make sure that your overflow tank isn't filled. If your head gasket wasn't fixed or you have compression/exhaust gases leaking into your system somewhere, the buildup of airpressure will literally push out coolant into your overflow tank and then just start to bubble air. This is what mine did when my head went south.
I also hear a hissing noise when after the van has been driven around coming from the right side of the motor but not sure what it is.That slight hissing sound is normal. If it was a liquid, you would either see a puddle form on the ground after a bit or would easily smell it. Coolant evaporating has a surgary "sweet" smell and is fairly distinctive. If you want an example, put a few drops on your exhaust manifold and take a wiff.
The low speed fan kicks on at 220 which is approximately vertical or the 2nd major tick mark. The high speed fan kicks on at 230 degrees which is about 2 minor ticks after vertical.
Since doing my heads earlier this spring, I pay more attention to the coolant needle, partially out of fear I guess. I never noticed it swinging from one tempature to another before I started having problems, but I do now and feel that it's just normal operation.
There also was a point soon after we got the head gasket replaced where they had forgotten to release the pressure and a hose busted above the oil filter and was shooting out coolant. We replaced that and then it overheated again and the mechanic that replaced the head gasket towed it back to his shop and came to the conclusion that there wasn't enough coolant in there and that the thermostat was fine. I added plenty before and now it's still overheating. We ordered a new radiator today and will put it in tomorrow.How hot is is overheating? Approximately where is it at on the gauge? There could be several things that are wrong. The big thing would be was the system properly bled of air? If it wasn't, many of the symptoms you described could happen due to air pockets.
Our vans are difficult to quickly remove all the air in a single setting if you don't have the proper equipment. The best way is to pull a vacuum on the entire system, then suck in the coolant. But many shops don't have that equipment and instead just open the bleeder valves to get as much as they can and figure that is good enough. And it is for the most part but it will take 4 or 5 complete cycles to properly remove most of the air from everywhere.
Are you losing a noticable amount of coolant? If you are having to add any coolant on a regular basis, then you do have a leak somewhere. But if your resevoir has stayed at the same level, then you aren't losing coolant.
Another thing to check is make sure your radiator cap is working correctly. If it's broken or corroded, it may not allow the pressure to build up, excess pressure released, or vacuum to draw coolant back in.
Pressure is required to get up to 13 or 14PSIs to allow better heat retention as well as boilover protection. Each PSI over atmosphere allows 3 additional degrees of boil over protection. If the pressure doesn't build up, then you lose that boilover protection. 14PSIs gives you 42 additional degrees. That's signifiacnt.
If the pressure gets to high, the cap opens and coolant (or air) is allowed to flow into the overflow tank. On a freshly flushed system, as the engine heats up, any air in the system will also heat up, usually surpassing the 14 PSI opening pressure of the cap. This air then leaks out and bubbles through the coolant in the overflow tank. Then, when the system cools, any remaining are contracts, pulling a vacuum. A different valve opens in the cap allowing coolant to be drawn back in to replace where that air was at that was displaced.
This process repeats several times to get the system properly bled. If the cap isn't working correctly, it's possible for coolant to be pushed out but not back, which caused colapsed hoses. If the coolant and air can't be released, then pressure can build up and burst a hose.
Finally, after a hard drive check to make sure that your overflow tank isn't filled. If your head gasket wasn't fixed or you have compression/exhaust gases leaking into your system somewhere, the buildup of airpressure will literally push out coolant into your overflow tank and then just start to bubble air. This is what mine did when my head went south.
I also hear a hissing noise when after the van has been driven around coming from the right side of the motor but not sure what it is.That slight hissing sound is normal. If it was a liquid, you would either see a puddle form on the ground after a bit or would easily smell it. Coolant evaporating has a surgary "sweet" smell and is fairly distinctive. If you want an example, put a few drops on your exhaust manifold and take a wiff.
94 Jimmy
08-01-2005, 05:23 PM
We have drifted away from the original post, but when you do any service which requires draining the cooling system be sure to use the air bleed screws to "burp" the system. There are two screws both are brass, one on top of a black pipe near the front of the engine compartment near the water pump, the other is on the thermostat housing near the transmission end of the engine.
With the engine hot and running open each slowly with a socket wrench or nut driver and allow any air to escape until you can see coolant coming out. This should be no more than a turn or two.
***Be carefull the coolant is hot and under pressure it can be nasty stuff.***
If your careful only a small amount of coolant will come out of each bleed. If you require additional bleeding, there is air geting into the system from somewhere, possibly a water jacket to combustion chamber leak.
Good luck.
94
With the engine hot and running open each slowly with a socket wrench or nut driver and allow any air to escape until you can see coolant coming out. This should be no more than a turn or two.
***Be carefull the coolant is hot and under pressure it can be nasty stuff.***
If your careful only a small amount of coolant will come out of each bleed. If you require additional bleeding, there is air geting into the system from somewhere, possibly a water jacket to combustion chamber leak.
Good luck.
94
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