Greetings,

Have a 95 Silhouette with 125K miles.

I purchased this car about 5 months ago for a road trip.. I have always been a big fan of the GM 3.8 engine..

Anyway this van stalls, would also stall while driving on the expressway. Service engine light was on, scanner said O2 sensor had that replaced and the stalling problem got worse. after this NO service engine light and no codes in history. then was told needed a tune up, replaced plugs and fuel filter wires looked ok still stalls. Next replaced the ignition module still stalls.. Sometimes the engine will run fine for 10 min or more then stalls. Also changed ignition switch. During all this we noticed that the intake gasket was leaking bad had that replaced still stalls. Thought problem might be cam sensor but mech says he checked the sensor and it is fine. Inspected wire harness on engine thought we found some crimps in wires but no change still same stalling issue.

Noticed that when car is connected to scanner just before it stalls the scanner loses communication and restarts.. scanner loses communication constantly. Car runs better after all this work but still stalls... While stopped at traffic light sometimes fine then sometimes the RPM up and down then stalls. While driving sometimes it feels like the engine revs and the service engine light will flicker. Scanner shows no codes or history of codes..

Overall the car runs better after all this work but it still stalls...

The mech is a buddy of mine so I am there when he is working on this but he seems kind of frustrated and is giving up.. I think maybe computer but not sure.. Any suggestions. Would like to keep if I can figure out this problem.. Any suggestions appreciated

Thanks

When you say "engine light" do you mean Service engine soon light?

If that light is comming on there should be a code set, the light can go away sometimes, but the code will be in history.

Check wires on 02 sensor, move them around have someone watch the dash for the light (SES)

My car is doing the exact thing down 7 weeks now!

Yes i mean the service engine light.. After the O2 sensor was replaced there are no codes and no codes in history.. The service engine light is not on currently...

Also recently my mech currently tried running with O2 sensor unplugged it, engine ran fine for about 15 - 25 min but then stalled.. weird thing is the Service engine light never came on. He wanted to see if the service engine light would come on and also thought the new O2 sensor might be bad but still stalled

The light should have come on

After about 15-25 minutes the eng would have been at operating temp! The computer will be looking for info from the o2 and ECT sensors, not getting the right info will a code and eng will stumble , sometimes die.

Make sure you bat cables are squeeky clean, clean all grounds , raditor support, both bolts on back of eng at trans.

You need that light (SES) to come on !

What exact codes came up?

I just thought of something

Time how long it take for eng to die from idel, also at what temp this occures, do this in the driveway at idel!
Write down results.

I had a 87 buick park ave with a 3.8 and this would happen. How I found it was to get the eng about to die a pour some water on the cam sensor, the eng would start running right then. It was a 35 dollar fix..

The park ave had a hood that rased toward the front of the car to open it ! I drove home with the hood rased. It was like a giant hood air scoop and was enought to cool the sensor to get home.
Good luck!!!!!!!!!!!!!!!!!

Currently there are no codes and no codes in history... The code that was present when the service engine light was on was for O2 sensor.. I dont remember the exact code but im sure it was for O2 sensor..

Battery is new and terminals are clean (they are not the original terminals but they are clean)..
I will check the grounds..

Its real hard to tell when it stalls sometimes it happens on a cold start after a 1 min and somtimes its fine. I drove this morning for about 30 min and it stalled twice while at traffic lights was ok on the express way..

I am leaning on the cam sensor the mech says he checked the cam on an ohm meter and it was good..

lookup DTC po341 cam/crank error, go autozone and sign up and you will get all of them. That code also means the circuts involed. Try that water trick.