[Badass94Cad]

I have a 3.8L Buick motor in my 1985 Regal, which was an old lady's car. It wasn't driven much, and sat for a while. I've tuned it all up with fresh everything, but there is still some vibration at low idle, and I notice the idle surging slightly, also at low idle. I guess I'm just picky, but I want to smooth it out completely.

My buddy suggested taking off the carburetor to clean the carbon off the bottom side, but another friend suggested the EGR could cause that problem too, as he learned from his Chevy 400. Now I always thought EGR didn't bother Chevy engines too much, but I know with Oldsmobile engines, a clogged EGR can be the difference between that sucker being a complete dog and running like a raped ape. I've been unable to find anything about these Buick motors other than Turbo hi-po info. Does anyone know if these EGRs like to clog up and make the car run kinda crappy, like in the Oldsmobile engines?

Thanks!
Jeff

 

[sinsear]

Hey check out oldspower.com their is some stuff about that engine.

 

[Badass94Cad]

Originally posted by sinsear@Sep 20 2005, 11:43 AM~3850736
Hey check out oldspower.com their is some stuff about that engine.

Good lookin bro. I checked it out, but didn't find the information I was looking for though. The Buick forum doesn't seem to get that much traffic either.

 

[blueouija]

Originally posted by Badass94Cad@Sep 20 2005, 10:39 AM~3849238
I have a 3.8L Buick motor in my 1985 Regal, which was an old lady's car.  It wasn't driven much, and sat for a while.  I've tuned it all up with fresh everything, but there is still some vibration at low idle, and I notice the idle surging slightly, also at low idle.  I guess I'm just picky, but I want to smooth it out completely.

My buddy suggested taking off the carburetor to clean the carbon off the bottom side, but another friend suggested the EGR could cause that problem too, as he learned from his Chevy 400.  Now I always thought EGR didn't bother Chevy engines too much, but I know with Oldsmobile engines, a clogged EGR can be the difference between that sucker being a complete dog and running like a raped ape.  I've been unable to find anything about these Buick motors other than Turbo hi-po info.  Does anyone know if these EGRs like to clog up and make the car run kinda crappy, like in the Oldsmobile engines?

Thanks!
Jeff

Hey Jeff....It could be the EGR.. my 91 caprice ran like shit and it turned out to be a bad EGR valve.. it was barely running at idle..

with the car running stick your fingers against the ERG valve diafram and puush the valve in and out..... does the idle get worse or better? try that...

 

[Badass94Cad]

Originally posted by blueouija@Sep 20 2005, 12:32 PM~3851023
Hey Jeff....It could be the EGR.. my 91 caprice ran like shit and it turned out to be a bad EGR valve.. it was barely running at idle..

with the car running stick your fingers against the ERG valve diafram and puush the valve in and out..... does the idle get worse or better? try that...

Good call, Jay. I'll try that.

Like I said, it's not reeeeal bad, it's just a gearhead will notice the slight vibration. Otherwise it runs and drives terrific. It just has this vibration at low idle that's kind of annoying to me. I think it's getting slightly better though as I blow some of the carbon out. I just took it out for the first beat run on the highway yesterday, so after the complete tune up, a tank of super and some Techron, and a beat run on the highway it's a little better but still not perfect.

 

[blueouija]

Originally posted by Badass94Cad@Sep 20 2005, 03:38 PM~3851060
Good call, Jay.  I'll try that. 

Like I said, it's not reeeeal bad, it's just a gearhead will notice the slight vibration.  Otherwise it runs and drives terrific.  It just has this vibration at low idle that's kind of annoying to me.    I think it's getting slightly better though as I blow some of the carbon out.  I just took it out for the first beat run on the highway yesterday, so after the complete tune up, a tank of super and some Techron, and a beat run on the highway it's a little better but still not perfect. 

def could be just from sitting... if so your right it will work it's way out...

 

[sancho12000]

I have the same problem can anybody give more info on this topic

 

[Torx]

how the fuck do you take it off with the carburetor still on?

theres only 2 bolts, but i tried replacing mine a while back and gave up cuz i couldnt figure out a way to get the bolts out. no tool or wrench would allow me

 

[Blue7]

Just For The Record The Only Way The Egr Affects The Running Of The Vehicle Is At Idle. If the valve is bad or leaking it will cause a vacuum leak which will cause a misfire. Or it could be plugged with carbon too. But as soon as you give it gas the valve no longer affects the way the motor runs. The egr valve is strickly for emissions. If you took the valve off and plugged the hole It would run the same.So Spray carb cleanner around it and if the rpms change you need a new valve. and dont go buy a cheap one you got to get one from the dealer or it will run shitty. Hope this Helps.

 

[Kurupt K]

two things, it could be the egr and in that case just cap it and secondly it could be a small vacume leak, so check all your hoses. both things happened on my car and i fixed them, now it runs great.

 

[1low64]

Wow...I would check the EGR...Remove it and block off the opening with a small piece of carboard...like from a case of beer :biggrin: then put it back on...if that changes the idle at all then that is your problem. The EGR valve works in open loop to help warm the engine faster by recurculating the gasses...hence the Exhaust Gas Recuirculation Valve. Its also for emitions purposes. If it is the EGR...do what homie up there^^^ said and get a good one somewhere around 80-100 bucks.