Help 91 camaro 3.1 white clouds from exhaust

chevrolet
camaro

#1

I have a 1991 Camaro RS 3.1l v6 I’m trying to figure out if I need heads or? Okay so I start the car and it idles great runs smooth and has power. It just pours smoke from the exhaust. I thought maybe a head gasket so just to make sure I checked the oil and no milky look to it. I drained all the antifreeze and made sure it was out of the engine completely (I didn’t let it get warm with it being dry) and it continued. Also it goes through spark plugs every 2 weeks or so with oil fouling. But it’s not a blue colored smoke it’s pure white unless you get the car up to 4200 rpm then it will have a blue tint to it, and I only did that once just to see if anything would change. Any and all help will be greatly appreciated
Edit: pcv valve was the first thing I replaced when this started, I forgot to put that the main reason I drained the coolant was because I was changing the water pump. I straight piped the car before winter and haven’t started it yet so I’m going to try today and see if it’s still all white or if it has a Blue tint to it. Thanks for the help so far. I’ll also check the vacuum modulator.


#2

Try changing the PCV valve. Sometimes they gum up and stick open.


#3

Sounds like an injector is stuck open and dumping loads of fuel into the engine. By the time you get to 4200 rpm the need for fuel is getting close to the actual supply. This engine has a throttle body fuel injection system so you should be able to see the excess fuel being sprayed in. You say it needs plugs every 2 weeks… What do the plugs look like? Are all fouled?

I’d guess a rebuilt throttle body is in order. They are $100 from RockAuto and not so hard to replace. That seems like cheap money. Seems like changing the PCV as @Cougar suggest would be a quick and cheap test, also.


#4

My '64 Fairlane did this once. It turned out to be a ruptured diaphragm in the vacuum modulator for the automatic tranny… :grin: Clouds of white smoke thick enough to butter on bread.

You have signs of burning oil and signs of burning coolant… or tranny fluid.
Personally, I’d start by performing compression and leakdown tests. The color of tailpipe smoke can be a bit misleading these days because the cat converter can capture a lot of the oil smoke. Testing the cylinders for integrity is the best way to find out what’s going on IMHO. The aforementioned are the best way to do that.

I recommend against doing this again. Your water pump is cooled and lubricated by the coolant, and running it in a dry state is a great way to destroy it.


#5

I agree that the smoke is from a leaking vacuum modulator on the transmission.

Remove the vacuum hose from the modulator, and if transmission fluid leaks out, the diaphragm in the modulator has ruptured.

Tester


#6

Plugs are Completely covered in burnt oil. The Chevy 3.1 v6 is actually mpfi not TBI. I was half asleep when I posted this so I didn’t get all of the details on what I’ve done down yet. I’m going to edit it now


#7

Remove a valve cover and inspect for sludge, if the oil drains in the cylinder heads are clogged oil will build up on top of the heads. The oil will leak past the valve guides and enter the cylinders and also enter the PCV system.


#8

I am slightly confused in your statement about the PCV valve. In your first post you stated the PCV valve was replaced with a new one. If the trouble started after you did that then replace the valve again because you got a defective one. I think you are saying that you replaced the PCV valve in an effort to fix the smoking problem. If so, then replacing the vacuum modulator should be your next step will most likely fix the trouble. Check your transmission fluid level.