1996 Buick Park Avenue 3800 intermittently stalls
08-26-2016, 02:39 AM
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1996 Buick Park Avenue 3800 intermittently stalls
Hello everyone. This is my first post. An elderly friend of mine has a low mileage (68k miles) 1996 Park Avenue base model with the 3.8l V6 (not supercharged). The problem he is having is that the car just intermittently stops as he is driving it. He only takes fairly short trips(say 5-20 miles), and just drives the surface streets – doesn’t go on thefreeways at all. From what I am hearing,the car might stall say 1-2 times per week, and at the worst, 2 times during the day. I believe that the car starts just fine when it is cold, and the stalling occurs after it is warm, and inmotion – say 30-40mph and not just when he comes to a stop. He says that when it does stall, he just pullsto the side of the road, and the car will usually restart immediately or maybe after waiting a minute or so. I’ve never been in the car when he is driving it.
He took the car to a nearby shop, and they found a sticking EGR valve, and installed a new one (BWD-EGR1095-CQ). Theyalso found the radiator ‘partially plugged and very contaminated with what appears to be dexcool coolant gone bad’, and that the radiator did not have coolant in it, but just water. They mentioned on the service report ‘found possible upper intake/plenum leak?’, but I’m not sure exactly what they saw. They ended up installing a new radiator, thermostat, and radiator hoses. They also pressure tested the cooling system, and found a leak from the heater hose elbow, so installed a new heater hose elbow and O-ring, and flushed the heater core and engine block. Theyalso found the engine oil low (not sure how low), so topped it off, plus installed a new air filter – old one was dirty. After the car kept stalling, the person at the shop said that they’rereally not sure what is causing the intermittent stalling – they test drove itfor 45’, and it was fine.
I said that I would take a look. After taking a look at various forums andYouTube videos for intermittent stalling causes on the 3800 engine, I:
During my checking, one of the vac line rubber connectors cracked at the throttle body, so I went to the wrecking yard to get a replacement. I also picked up a used MAP(16187556) and PCV valve. *** I was going to replace the black cover that goes over the PCV valve and that the MAP sensor sticks into, but it broke on the one at the wrecking yard, plus I brokethe one on the car when I got back. Doesanyone have any part number for it? Any suggestions on GM websites with good part diagrams and part numbers? Dorman sells a replacement part 47033, but the top retainer pieces look different.
From what I’ve read on 3800 intermittently stalling, the MAF often gives problems, and the ICM and CPS can be temperature sensitive. We’re going to see if the recent work has helped, but if the car keeps intermittently stalling, then would you suggest doing something with the ICM, CPS, or ??? If a new/rebuilt MAF should be installed,then are there any suggestions on what brand to go with? Thanks!!! - Jim
He took the car to a nearby shop, and they found a sticking EGR valve, and installed a new one (BWD-EGR1095-CQ). Theyalso found the radiator ‘partially plugged and very contaminated with what appears to be dexcool coolant gone bad’, and that the radiator did not have coolant in it, but just water. They mentioned on the service report ‘found possible upper intake/plenum leak?’, but I’m not sure exactly what they saw. They ended up installing a new radiator, thermostat, and radiator hoses. They also pressure tested the cooling system, and found a leak from the heater hose elbow, so installed a new heater hose elbow and O-ring, and flushed the heater core and engine block. Theyalso found the engine oil low (not sure how low), so topped it off, plus installed a new air filter – old one was dirty. After the car kept stalling, the person at the shop said that they’rereally not sure what is causing the intermittent stalling – they test drove itfor 45’, and it was fine.
I said that I would take a look. After taking a look at various forums andYouTube videos for intermittent stalling causes on the 3800 engine, I:
- Scanned it with my Autel MS310 scanner – it isa basic/inexpensive scanner. There weren’t any codes, but I’ll list somelive data further down in the post.
- Withthe engine idling, I wiggled the wires to the MAF, TPS, MAP, and ICM, and thespeed of the engine did not change. I didn’t try to wiggle the wires to the CPS as the accessory belt etc. is nearby.
- I removed the MAF (model AFH50M-03A with three bolts) and rubber intake tube, and sprayed thru the screen with throttle body cleaner to try to clean the throttlebody and IAC. The MAF looked physically OK, so I sprayed it with MAF cleaner.
- At idle, I removed the vacuum line to the fuel pressure regulator, and didn’t see any gas leaking or small from the regulator, but from one YouTube video on theforum, it looks like I should have left the line disconnected for say 2minutes. There wasn’t any haze or smellof coolant coming from the exhaust pipe. The oil also looks clear and not milky.
- I loosened the wires to the coil packs, and with insulated pliers, pulled up onthe connectors one at a time, and the engine slowed, so all of the cylinders were getting spark.
During my checking, one of the vac line rubber connectors cracked at the throttle body, so I went to the wrecking yard to get a replacement. I also picked up a used MAP(16187556) and PCV valve. *** I was going to replace the black cover that goes over the PCV valve and that the MAP sensor sticks into, but it broke on the one at the wrecking yard, plus I brokethe one on the car when I got back. Doesanyone have any part number for it? Any suggestions on GM websites with good part diagrams and part numbers? Dorman sells a replacement part 47033, but the top retainer pieces look different.
From what I’ve read on 3800 intermittently stalling, the MAF often gives problems, and the ICM and CPS can be temperature sensitive. We’re going to see if the recent work has helped, but if the car keeps intermittently stalling, then would you suggest doing something with the ICM, CPS, or ??? If a new/rebuilt MAF should be installed,then are there any suggestions on what brand to go with? Thanks!!! - Jim
08-26-2016, 02:50 AM
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I forgot to mention, that the shop also put in new spark plug wires and spark plugs.
Just wondering - I didn't see any button to edit/correct, so I just replied with this additional info. Is there a way to edit threads/posts? Thanks!! - Jim
Just wondering - I didn't see any button to edit/correct, so I just replied with this additional info. Is there a way to edit threads/posts? Thanks!! - Jim
08-26-2016, 11:26 AM
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You can only edit, within a few minutes, after that you can't......
A lot of work done, that didn't fix the problem.....Sticking EGR? Yeah, OK......think they saw him coming......I would remove the throttle body(you will need new gasket) and remove IAC......clean pintle on IAC and clean passageway in throttle body......then clean throttle body plate and bore.....
Relieve coolant pressure by removing radiator cap, before removing throttle body....you will lose a little coolant when removing the throttle body, so place rags under it.....reinstall, and top off coolant....
A lot of work done, that didn't fix the problem.....Sticking EGR? Yeah, OK......think they saw him coming......I would remove the throttle body(you will need new gasket) and remove IAC......clean pintle on IAC and clean passageway in throttle body......then clean throttle body plate and bore.....
Relieve coolant pressure by removing radiator cap, before removing throttle body....you will lose a little coolant when removing the throttle body, so place rags under it.....reinstall, and top off coolant....
08-26-2016, 02:26 PM
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Thanks for the info on this. On a Honda, I could see and try to clean the throttle plate really easily, but with the screen on the 3800 throttle body, I really couldn't see anything. The YouTube video showing cleaning of the throttle body just had the throttle body cleaner being sprayed thru the screen.
I assume that there is just one gasket from the throttle body to the intake manifold. Is there any gasket under the IAC? If I do remove the throttle body, then I guess that that will allow me to take a good look inside the manifold for any coolant etc. It looked like the throttle body is attached with three nuts, plus a bracket on the front part. Does the bracket just need to be loosened to the throttle body, or does the bracket need to be loosened where it connects to the engine block? The access seems pretty limited. Any websites with good part diagrams and part numbers? Thanks!! - Jim
08-26-2016, 10:09 PM
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The IAC has an o-ring, not a gasket......you remove the bracket from throttle body and then the throttle body is removed completely...
What it looks like cleaned.....
What it looks like cleaned.....
08-26-2016, 11:59 PM
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Damn, that'* clean... I was worried that after removing the bracket from the throttle body, that there wouldn't be enough room to slide the throttle body off of the studs to get it off.
I know that a dirty throttle body can cause problems, but you feel that it could cause intermittent stalling when the engine is warm?
I'll look into a throttle body gasket as well as the IAC O-ring. I haven't ordered anything yet, but I'll probably just order everything thru Amazon. Do you have any websites for GM parts where they give a parts diagram complete with part numbers? Thanks!!! - Jim
08-27-2016, 04:04 AM
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Ordering from Amazon is fine, also RockAuto.com
If need be I can get you any part numbers.
The TB Gasket is 4.99 on Amazon with free shipping if your order totals 25.00
Or Rock Auto has it for 3.40 plus shipping
FEL-PRO 61093 is the Fel-Pro one
There is also an AC Delco one, a black one that some say is a bit better, it is almost 14.00 plus shipping though, the Fel-PRO will do fine.
I bet the IAC O-Ring is fine, mine was ok at 133k, so his should be fine, just inspect it for cracks or wear...
As for the heating up and stalling issue, my first thought was the ICM, ignition control module, they occasionally go bad and stall form heatsoak, but the car usually has to sit a while before it will start right back up.
The fact that they mention possible UIM/plenum leak, and the coolant going to sludge, that makes me think while you have the throttle body off you may want to consider removing the upper intake, then lower intake, and replacing the old plastic LIM gasket with the aluminum framed gaskets, and replace the plastic coolant elbows with the Dorman Aluminum ones.
There have been reports of cars with as low of mileage as his having this gasket fail, an to be honest it is only a matter or time before it fails if it has not started to already.
It is a lengthy job for a DIY'er, would probably take all day, parts are not too much though.
If you consider this then I'll gladly get a parts list for you.
I have a 96' PA and did the job on my own, it was not too bad of a job really.
If need be I can get you any part numbers.
The TB Gasket is 4.99 on Amazon with free shipping if your order totals 25.00
Or Rock Auto has it for 3.40 plus shipping
FEL-PRO 61093 is the Fel-Pro one
There is also an AC Delco one, a black one that some say is a bit better, it is almost 14.00 plus shipping though, the Fel-PRO will do fine.
I bet the IAC O-Ring is fine, mine was ok at 133k, so his should be fine, just inspect it for cracks or wear...
As for the heating up and stalling issue, my first thought was the ICM, ignition control module, they occasionally go bad and stall form heatsoak, but the car usually has to sit a while before it will start right back up.
The fact that they mention possible UIM/plenum leak, and the coolant going to sludge, that makes me think while you have the throttle body off you may want to consider removing the upper intake, then lower intake, and replacing the old plastic LIM gasket with the aluminum framed gaskets, and replace the plastic coolant elbows with the Dorman Aluminum ones.
There have been reports of cars with as low of mileage as his having this gasket fail, an to be honest it is only a matter or time before it fails if it has not started to already.
It is a lengthy job for a DIY'er, would probably take all day, parts are not too much though.
If you consider this then I'll gladly get a parts list for you.
I have a 96' PA and did the job on my own, it was not too bad of a job really.
08-27-2016, 06:57 PM
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The fact that they mention possible UIM/plenum leak, and the coolant going to sludge, that makes me think while you have the throttle body off you may want to consider removing the upper intake, then lower intake, and replacing the old plastic LIM gasket with the aluminum framed gaskets, and replace the plastic coolant elbows with the Dorman Aluminum ones.
There have been reports of cars with as low of mileage as his having this gasket fail, an to be honest it is only a matter or time before it fails if it has not started to already.
It is a lengthy job for a DIY'er, would probably take all day, parts are not too much though.
If you consider this then I'll gladly get a parts list for you.
I have a 96' PA and did the job on my own, it was not too bad of a job really.
There have been reports of cars with as low of mileage as his having this gasket fail, an to be honest it is only a matter or time before it fails if it has not started to already.
It is a lengthy job for a DIY'er, would probably take all day, parts are not too much though.
If you consider this then I'll gladly get a parts list for you.
I have a 96' PA and did the job on my own, it was not too bad of a job really.
I've read about the upper manifold sometimes needing to be replaced from being melted from the EGR tube as far as I can understand. How do you know if the upper manifold needs to be replaced - do you look for a leak from a certain location, and if so, is it visible with everything assembled, or only with the manifold removed from the car? I've read a little about LIM gasket replacements, but is the LIM itself usually OK and just the gaskets need to be replaced? I've watched a few YouTube videos so far. I'm not sure if I'll need to do all of this, but if you have a parts list and could post it, I'd appreciate it. Many thanks!!!
PS - does anyone have any info what a scanner should show for the spark advance at idle? As I mentioned, I saw readings like -12 and -19, and the negative readings seem unusual to me. - Jim
08-27-2016, 07:52 PM
#9
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True Car Nut
You are very welcome.
Throttle Body Nut
89 lb in
Throttle Body Support Bolt
89 lb in
Throttle Body Support Stud
53 lb in
------------------------
You can inspect the UIM around the EGR port and it is pretty easy to tell if it has been damaged enough to warrant replacing.
Another thing, when you remove the TB Gasket, if the plastic around the UIM that holds that gasket in places seems really safe, and or brakes off while replacing the gasket, then replace the whole UIM.
The LIM is always fine, just inspect it for big pits in the area the gasket seals to, mine was fine with only small pits, but to be safe I still mixed some JB Weld and used a razor to scrape it into the pits, then I used the razor to carefully remove any excess JB Weld.
That is most likely not necessary though.
The main thing with the LIM is to remove that old EGR Stove Pipe, Vice Grips will work.
Save the old one to sue to tap the smaller one down into the LIM, it should fit almost flush, mine was like maybe 3/16" from being totally flush, that is fine..
The smaller EGR Stove Pipe comes with the Upper Intake Kit I believe it was...
This is not something that will have to be done right away unless the car is having water or coolant levels constantly drop. but it is the main repair that the motor needs to ensure it will last a long time, like I was saying it is not if it will fail, just a matter of when the LIM Gasket will fail.
I'll get my old thread from another forum, and I think I still have a link to a good pdf that would help with the job.
I'll get a parts list for you after I walk my dogs.
Throttle Body Nut
89 lb in
Throttle Body Support Bolt
89 lb in
Throttle Body Support Stud
53 lb in
------------------------
You can inspect the UIM around the EGR port and it is pretty easy to tell if it has been damaged enough to warrant replacing.
Another thing, when you remove the TB Gasket, if the plastic around the UIM that holds that gasket in places seems really safe, and or brakes off while replacing the gasket, then replace the whole UIM.
The LIM is always fine, just inspect it for big pits in the area the gasket seals to, mine was fine with only small pits, but to be safe I still mixed some JB Weld and used a razor to scrape it into the pits, then I used the razor to carefully remove any excess JB Weld.
That is most likely not necessary though.
The main thing with the LIM is to remove that old EGR Stove Pipe, Vice Grips will work.
Save the old one to sue to tap the smaller one down into the LIM, it should fit almost flush, mine was like maybe 3/16" from being totally flush, that is fine..
The smaller EGR Stove Pipe comes with the Upper Intake Kit I believe it was...
This is not something that will have to be done right away unless the car is having water or coolant levels constantly drop. but it is the main repair that the motor needs to ensure it will last a long time, like I was saying it is not if it will fail, just a matter of when the LIM Gasket will fail.
I'll get my old thread from another forum, and I think I still have a link to a good pdf that would help with the job.
I'll get a parts list for you after I walk my dogs.
08-27-2016, 09:52 PM
#10
Senior Member
True Car Nut
A part list if you end up doing the UIM/LIM job.
The UIM I suggest should be better than the Dorman one, as it has a Metal-cert sleeved EGR port, that with the smaller EGR stove pipe will ensure that EGR issue never happens again.
Upper Intake that comes with UIM Gasket and TB Gasket.
Part Number ATP 106001
https://www.amazon.com/ATP-Automotiv.../dp/B000C8T7X6
Dorman Coolant Elbows, you will only use one of the two.
Dorman 47065HP
https://www.amazon.com/Dorman-47065H...WQT36BGG5KRMBH
Fel-PRO LIM Gasket
Felpro MS 98014 T Intake Manifold Gasket
https://www.amazon.com/Felpro-MS-980...7QB4D2RBRCDSRZ
Thermostat - Usually most go ahead and change this while they are doing the job, not totally necessary though, it comes with the rubber gasket, I always still use the paper style along with it for added leak protection, a paper one comes with the LIM Gasket Kit.
ACDelco 131-120 GM Original Equipment 195 Degrees Engine Coolant Thermostat with Gasket
https://www.amazon.com/ACDelco-131-1...CWTE044QFF6SFJ
When done you will need to change the oil, and I'd flush the coolant system out good, if you go with a full flush you can change to another type of coolant, but to be honest if coolant levels are always maintained, the system is properly maintained, and no air is left trapped in the system, then Dex Cool is not a problem, I have used it in my 96 PA for 15 years, it has technically ran Dex Cool its while life, same with my 2006 Grand Prix..
To some this post may seem off topic, but keep in mind a possible UIM leak was mentioned, and if the motor ends up hydro-locking then you could be looking at replacing toe motor, or if lucky only having it rebuilt..
The UIM I suggest should be better than the Dorman one, as it has a Metal-cert sleeved EGR port, that with the smaller EGR stove pipe will ensure that EGR issue never happens again.
Upper Intake that comes with UIM Gasket and TB Gasket.
Part Number ATP 106001
https://www.amazon.com/ATP-Automotiv.../dp/B000C8T7X6
Dorman Coolant Elbows, you will only use one of the two.
Dorman 47065HP
https://www.amazon.com/Dorman-47065H...WQT36BGG5KRMBH
Fel-PRO LIM Gasket
Felpro MS 98014 T Intake Manifold Gasket
https://www.amazon.com/Felpro-MS-980...7QB4D2RBRCDSRZ
Thermostat - Usually most go ahead and change this while they are doing the job, not totally necessary though, it comes with the rubber gasket, I always still use the paper style along with it for added leak protection, a paper one comes with the LIM Gasket Kit.
ACDelco 131-120 GM Original Equipment 195 Degrees Engine Coolant Thermostat with Gasket
https://www.amazon.com/ACDelco-131-1...CWTE044QFF6SFJ
When done you will need to change the oil, and I'd flush the coolant system out good, if you go with a full flush you can change to another type of coolant, but to be honest if coolant levels are always maintained, the system is properly maintained, and no air is left trapped in the system, then Dex Cool is not a problem, I have used it in my 96 PA for 15 years, it has technically ran Dex Cool its while life, same with my 2006 Grand Prix..
To some this post may seem off topic, but keep in mind a possible UIM leak was mentioned, and if the motor ends up hydro-locking then you could be looking at replacing toe motor, or if lucky only having it rebuilt..
