O2 Sensor
Oleshka10
11-04-2004, 05:18 PM
My question is simple, can a bad O2 Sensor cause a shake, like the car isn't getting enogh fuel or spark, the car has only 91000 miles runs like a champ, just had the injectors cleaned, a tune up, but still once in great while i get this weird shake, and when i gas it hard it goes away
Please help
Thanks
Please help
Thanks
buickmastermind
11-04-2004, 06:43 PM
What kind of shake? What conditions does it happen under? What year is your car?
I haven't had an O2 sensor cause a shake, but other things may be causing the problem.
I haven't had an O2 sensor cause a shake, but other things may be causing the problem.
Oleshka10
11-04-2004, 06:59 PM
It happens right after it rains for about 1-2 days, the car is a 1995, it is more like the car isn't getting enough spark or fuel, but plugs and wires are new, injectors are clean. Hope this helps
P.S thank for the quick reply
P.S thank for the quick reply
happydog500
11-04-2004, 10:32 PM
For what it's worth, I had a 91 Olds Ceaira that kind of did the same thing. It couldn't be the plug wires since I resontly got new, good quality ones. I took it to a friends house and we checked the new wires with a volt meeter. Sure enough, one was bad.
Wanted to say, don't know at all if it's plug wires, just that because you got new ones, doesn't mean it can't be plug wires.
Remember!! I don't know what the problem is with your car. Just passing along that even new wires can be falty. I dorve my car for months not being able to find the problem, since I had NEW plugs. Chris.
Wanted to say, don't know at all if it's plug wires, just that because you got new ones, doesn't mean it can't be plug wires.
Remember!! I don't know what the problem is with your car. Just passing along that even new wires can be falty. I dorve my car for months not being able to find the problem, since I had NEW plugs. Chris.
buickmastermind
11-05-2004, 01:06 AM
Right after it rains? Hmm. Spray water (from a hose) ONLY on the ignition coils (don't have the car running, unless you want to get shocked). Then start the car, and driver it around for a bit. If you get the same shudder, you have coil(s) that are dying. Post what you find out.
avatar307
11-05-2004, 11:07 AM
Man alive, it would have to rain like no other to get the ICM wet. It's located high in the engine compartment, and the under hood is pretty well sealed from all sides. (Even going through the radiator or up from the bottom, it would be near impossible for rain water to reach the ICM.) Maybe closing the hood and spraying the whole car with water and trying to figure out how, why, and where the water is getting under the hood.
That, of course, assumes that it only happens after it rains. Does it only happen right after it rains? More specifically, right after the car is parked in the rain or right after the car is driven in the rain?
This weird shake/shudder. Does the car actually vibrate or is it more of a noise? Can you feel the vibration in your seat, or just through your hand on the steering wheel?
The fact that you state "when I gas the engine, the shudder goes away" makes me think it has nothing to do with the engine missing or misfiring. Pressing down on the accelerator should make an engine miss or misfire more prevalent, as it would cause such to occur more rapidly.
However, pressing down on the gas pedal, would cause your transmission to downshift in response to the detent of the gas pedal (as determined by the trottle position sensor). Due to that, this is most likely related to your transmission and not necessarily related to anything being broken.
When does the "shudder" occur? When the engine is in park? In neutral? In drive and stopped? At 25MPH? How about in over-drive at 40-45MPH when encountering a slight uphill grade?
(A slight uphill grade being defined as one that does not necessarily require you to press down on the gas pedal, or the transmission to downshift, in order to maintain your speed within 5 MPH.)
Again, in reference to the characteristics of this "wierd shake" and/or "shudder." Does this shudder have more of the audible characteristics of a shudder than the physical characteristics? That is, do you hear it more than you actually feel it? (Remember, sometimes our minds play tricks on us. If we hear what sounds like a shudder, our mind will be sure we felt the shudder too. I know I was convinced I was until I really started paying attention.)
Now... if this condition most often happens in OD around 45MPH and is more a sound then... you are most likely hearing the Torque Converter Clutch Solinoid (TCC Solinoid) attempting to engage the TCC.
It's a classic "ghost" problem with the 4T60-E transmission, and does not represent a mechanical problem. The way I understand it, this occurs due to some programing changes in the PCM. The PCM wants to engage/disengage the TCC in response to increased engine RPM relative to speed. However, the load on the transmission in response to the grade is not great enough to cause the TCC to lock/slip or the transmission to downshift.
Now, back to my references to water. It's unlikely the ICM is getting wet (unless you regurally have heavy rain with 50MPH winds). It's relatively well protected compared to other engine electical connectors (though I do disagree with it's wiring harness).
However, there are many other connectors that regurally get wet. One you'll see mentioned quite often is the crankshaft sensor... which is relatively vunerable where it's located... but also not my point.
On the complete opposite side of the engine compartment, below the intake, is the transmission bell housing. On the front, upper side of the bell housing is a 5 to 7-wire electrical connector. This controls the TCC, PWM, A-shift, and B-shift solinoids, and the transmission temperature sensor.
If one of those wires is cracked/crushed/loose/damaged and got wet, that could cause a problem. This is quite possible do to the proximity of this connector to the open under carriage and front drivers wheel.
A problem could easily occur because the water does not have to short two pins to cause one of the solinoids to behave erratically. One pin (usually the top pin E) provides continuous power to all solinoids whenever the ignition is on. The solinoids are engaged by the PCM applying ground to each of 4 other wires.
If one of the wires is damaged, and the connector got wet, that would allow the wire to short to the transmission bell housing. Thereby, finding a chassis ground and causing one of the solinoids to engage both when it's not supposed to and in an erratic random fashion (i.e. Not consistantly at 45MPH like "TCC shudder noise").
This would constitute a mechanical problem that needs to be repaired. It could even lead to a transmission failure in theory.
Not that above I have described TWO different senarios. One, TCC shudder noise, which is normal behavior for the 4T60-E transmission and not a repairable mechanical problem. Two, the transmission solinoid connector getting wet, which is mechanical problem that needs to be repaired. The two are only related in a mechanical sense, and not in a diagnostic sense. One is normal, one is a problem, but they both serve as a reference to the other and aid in the explaintion of my theory.
It should also be noted that I tend to jump to most complicated conclusions first. Whereas, most people and good diagnostics, start with the simplest explainations first. That being the old motto, "is there fuel, is there spark?"
However, I also have a 95 LeSabre, with 175,000 miles, and my ICM has never given me any problem. (Except one failed coil that was replaced under warrenty at 15,000 miles.)
However, I do regurally observe TCC shudder noise from my 4T60-E transmission. Driving in D instead of OD for city traffic seems to limit this somewhat. The TCC Solinoid engages in both D and OD, but placing the transmission in D changes the shift points somewhat (at least as far as the PCM is concerned). From my understanding, the TCC shudder noise occurs due to a programing change to the PCM designed to increase fuel efficiency. Thereby, it primarily affects the transmission in OD, as OD exists to increase fuel efficiency.
That, of course, assumes that it only happens after it rains. Does it only happen right after it rains? More specifically, right after the car is parked in the rain or right after the car is driven in the rain?
This weird shake/shudder. Does the car actually vibrate or is it more of a noise? Can you feel the vibration in your seat, or just through your hand on the steering wheel?
The fact that you state "when I gas the engine, the shudder goes away" makes me think it has nothing to do with the engine missing or misfiring. Pressing down on the accelerator should make an engine miss or misfire more prevalent, as it would cause such to occur more rapidly.
However, pressing down on the gas pedal, would cause your transmission to downshift in response to the detent of the gas pedal (as determined by the trottle position sensor). Due to that, this is most likely related to your transmission and not necessarily related to anything being broken.
When does the "shudder" occur? When the engine is in park? In neutral? In drive and stopped? At 25MPH? How about in over-drive at 40-45MPH when encountering a slight uphill grade?
(A slight uphill grade being defined as one that does not necessarily require you to press down on the gas pedal, or the transmission to downshift, in order to maintain your speed within 5 MPH.)
Again, in reference to the characteristics of this "wierd shake" and/or "shudder." Does this shudder have more of the audible characteristics of a shudder than the physical characteristics? That is, do you hear it more than you actually feel it? (Remember, sometimes our minds play tricks on us. If we hear what sounds like a shudder, our mind will be sure we felt the shudder too. I know I was convinced I was until I really started paying attention.)
Now... if this condition most often happens in OD around 45MPH and is more a sound then... you are most likely hearing the Torque Converter Clutch Solinoid (TCC Solinoid) attempting to engage the TCC.
It's a classic "ghost" problem with the 4T60-E transmission, and does not represent a mechanical problem. The way I understand it, this occurs due to some programing changes in the PCM. The PCM wants to engage/disengage the TCC in response to increased engine RPM relative to speed. However, the load on the transmission in response to the grade is not great enough to cause the TCC to lock/slip or the transmission to downshift.
Now, back to my references to water. It's unlikely the ICM is getting wet (unless you regurally have heavy rain with 50MPH winds). It's relatively well protected compared to other engine electical connectors (though I do disagree with it's wiring harness).
However, there are many other connectors that regurally get wet. One you'll see mentioned quite often is the crankshaft sensor... which is relatively vunerable where it's located... but also not my point.
On the complete opposite side of the engine compartment, below the intake, is the transmission bell housing. On the front, upper side of the bell housing is a 5 to 7-wire electrical connector. This controls the TCC, PWM, A-shift, and B-shift solinoids, and the transmission temperature sensor.
If one of those wires is cracked/crushed/loose/damaged and got wet, that could cause a problem. This is quite possible do to the proximity of this connector to the open under carriage and front drivers wheel.
A problem could easily occur because the water does not have to short two pins to cause one of the solinoids to behave erratically. One pin (usually the top pin E) provides continuous power to all solinoids whenever the ignition is on. The solinoids are engaged by the PCM applying ground to each of 4 other wires.
If one of the wires is damaged, and the connector got wet, that would allow the wire to short to the transmission bell housing. Thereby, finding a chassis ground and causing one of the solinoids to engage both when it's not supposed to and in an erratic random fashion (i.e. Not consistantly at 45MPH like "TCC shudder noise").
This would constitute a mechanical problem that needs to be repaired. It could even lead to a transmission failure in theory.
Not that above I have described TWO different senarios. One, TCC shudder noise, which is normal behavior for the 4T60-E transmission and not a repairable mechanical problem. Two, the transmission solinoid connector getting wet, which is mechanical problem that needs to be repaired. The two are only related in a mechanical sense, and not in a diagnostic sense. One is normal, one is a problem, but they both serve as a reference to the other and aid in the explaintion of my theory.
It should also be noted that I tend to jump to most complicated conclusions first. Whereas, most people and good diagnostics, start with the simplest explainations first. That being the old motto, "is there fuel, is there spark?"
However, I also have a 95 LeSabre, with 175,000 miles, and my ICM has never given me any problem. (Except one failed coil that was replaced under warrenty at 15,000 miles.)
However, I do regurally observe TCC shudder noise from my 4T60-E transmission. Driving in D instead of OD for city traffic seems to limit this somewhat. The TCC Solinoid engages in both D and OD, but placing the transmission in D changes the shift points somewhat (at least as far as the PCM is concerned). From my understanding, the TCC shudder noise occurs due to a programing change to the PCM designed to increase fuel efficiency. Thereby, it primarily affects the transmission in OD, as OD exists to increase fuel efficiency.
buickmastermind
11-05-2004, 12:18 PM
To my knowledge, the coil assembly on the 95 is located toward the front of the car, right in the path of the radiator. Meaning, water can be sprayed at the grille, and pass through the radiator, and right on the coils. But, don't quote me on that, as I am not entirely sure that the coils are unshielded from the rain that enters through the grille. I have found that even if the coils are located in the back of the engine compatment, right over the valve cover, rain can still effect them.
At any rate, they are suspect because the car has 91000 miles. I have found that coils don't normally last over 100,000 if they are the original factory coils, or the cheap brand at the nearby autoshop. Although, the more expensive coils have seemed to pay for themselves by my not having to change them every 100,000 miles or so.
Avatar might be right about the tranny, I am not familiar with that model of the tranny, so don't rule it out. Just make sure that you can rule out the coils, a very common cause of a shudder, vibration, or fuel starvation feeling.
At any rate, they are suspect because the car has 91000 miles. I have found that coils don't normally last over 100,000 if they are the original factory coils, or the cheap brand at the nearby autoshop. Although, the more expensive coils have seemed to pay for themselves by my not having to change them every 100,000 miles or so.
Avatar might be right about the tranny, I am not familiar with that model of the tranny, so don't rule it out. Just make sure that you can rule out the coils, a very common cause of a shudder, vibration, or fuel starvation feeling.
avatar307
11-05-2004, 12:40 PM
The ICM and coils on the 1995 LeSabre VIN L (SFI 3.8 non-supercharged) engine are located near the alternator. Front of the engine compartment, passenger side, elevated 2-3 inches above the valve cover. This places them just barely inside the side perimeter of the radiator, and above the upper perimeter.
My point is, rain does not regually pass through the radiator and A/c condenser on the front of a vehicle. Air does b/c air has a much lighter specific gravity and weaker molecular bonds. That's where my comment pertaining to heavy rain and 50MPH winds comes in, as that would be my estimate of the conditions required to push any significant amount of water into the engine compartment through the radiator. The underside of the front of the engine compartment is sealed, which makes is difficult for water to enter that way as well. However, the opposite side of the engine compartment, near the transmission, holds the air intake as well, which means a purposeful forward passage exists to allow efficient air flow.
My 1995 has 175,000 miles and I've never had even a hit of problems out of my ICM. Like I have stated in other posts, I had 125,000+ on a set of spark plugs without a hiccup or a delayed start. I beileve the older ICMs from the 85-91 Buicks had some issues, as I've seen a lot of post about them melting and the like. However, the LeSabre was nearly completely redesigned in 1992 and I expect the ICM was replaced.
My point is, rain does not regually pass through the radiator and A/c condenser on the front of a vehicle. Air does b/c air has a much lighter specific gravity and weaker molecular bonds. That's where my comment pertaining to heavy rain and 50MPH winds comes in, as that would be my estimate of the conditions required to push any significant amount of water into the engine compartment through the radiator. The underside of the front of the engine compartment is sealed, which makes is difficult for water to enter that way as well. However, the opposite side of the engine compartment, near the transmission, holds the air intake as well, which means a purposeful forward passage exists to allow efficient air flow.
My 1995 has 175,000 miles and I've never had even a hit of problems out of my ICM. Like I have stated in other posts, I had 125,000+ on a set of spark plugs without a hiccup or a delayed start. I beileve the older ICMs from the 85-91 Buicks had some issues, as I've seen a lot of post about them melting and the like. However, the LeSabre was nearly completely redesigned in 1992 and I expect the ICM was replaced.
Oleshka10
11-05-2004, 12:45 PM
Thanks for the quick reply guys
I did check the coils everything seems to be ok, i sprayed the water on the coils drove for 2 weeks it was ok, i did take them of yestarday and cleaned them, i am a bit reluctant to change them because, they are still not bad (advised by mechanic), and it only does that after it rains, after that i guess it dries quicly and goes away
Please don't hesitate to offer any other advise
Thanks
I did check the coils everything seems to be ok, i sprayed the water on the coils drove for 2 weeks it was ok, i did take them of yestarday and cleaned them, i am a bit reluctant to change them because, they are still not bad (advised by mechanic), and it only does that after it rains, after that i guess it dries quicly and goes away
Please don't hesitate to offer any other advise
Thanks
buickmastermind
11-05-2004, 04:47 PM
Thankfully my ICM has never melted. Yet. I have had a bad coil fry my computer, though, and temperatures under 50 degrees are a known cause of a coil that is going bad to stop functioning. Anyway, now that we know it isn't the coils, I have another idea. This is a long shot, but if water gets into the gas tank somehow or somewhere similar, that can cause a problem, but like I said, it's not likely. I think that it is a component that is removed from the heat of the motor, because if it were near the motor, it wouln'd sit for 1-2 days causing problems. If it is even at all related to the rain.
avatar307
11-05-2004, 09:56 PM
*nod, nod* I agree. Thanks for saying something... I've been thinking that in the back of my mind through it all. I just keep writing it off to exageration of the problem.
It doesn't make sense for the car to act stupid for 1-2 days after it rains and only after it rains. One good engine warm up should burn off any and all water that is on anything metal.
The only thing that I have ever gotten wet, that has caused me problems for more than 5 minutes, was my air filter. My street flooded (again) and the car didn't quite make it to the other side. (Water crested the middle of the windsheild before it suffocated and died... I was impressed.)
After that, I'm sure the intake had a little water in it and the air filter was soaked. Thus, it didn't suprize me when it acted up the next couple days. Tried to die once, a little sputtering and hesitating, but it was 100% better in a couple days.
Now my car has sat in some good sized rain storms, and I've never had a problem the next day. (I mean... rain storms the fill the street up to chest level it comes down so hard.) And I even had the drivers fender off for like 6 months, directly exposing the intake. (Though I can't remember if it rained during that time.)
Never had anything resembling a problem except that one time I took the car scuba diving. (More boating, as the car was floating there for a couple seconds, before the inside flooded.)
It doesn't make sense for the car to act stupid for 1-2 days after it rains and only after it rains. One good engine warm up should burn off any and all water that is on anything metal.
The only thing that I have ever gotten wet, that has caused me problems for more than 5 minutes, was my air filter. My street flooded (again) and the car didn't quite make it to the other side. (Water crested the middle of the windsheild before it suffocated and died... I was impressed.)
After that, I'm sure the intake had a little water in it and the air filter was soaked. Thus, it didn't suprize me when it acted up the next couple days. Tried to die once, a little sputtering and hesitating, but it was 100% better in a couple days.
Now my car has sat in some good sized rain storms, and I've never had a problem the next day. (I mean... rain storms the fill the street up to chest level it comes down so hard.) And I even had the drivers fender off for like 6 months, directly exposing the intake. (Though I can't remember if it rained during that time.)
Never had anything resembling a problem except that one time I took the car scuba diving. (More boating, as the car was floating there for a couple seconds, before the inside flooded.)
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