Puff of bluish-white smoke at startup

[turbojimmy]

....and it's running rich. Smells rich but only smokes at startup. Just a puff at startup. No smoke at idle, WOT or any other time. With steady throttle the car surges but it's subtle.

BTW this is my brother's car, not mine.

I know bluish-white smoke sounds like oil but it smells like gas. We've had the turbo rebuilt and the motor is brand new. Engine guy is adamant that it's NOT the motor that's smoking - it's something else. I tend to agree but can't figure it out. Everything is totally stock on the car - I mean EVERYTHING. Only exception is removal of the cat (new one on the way).

We thought maybe the problem was all the cocaine stashed under the console but even after we removed it the car still smokes (you find interesting things in these salvage cars - I had already thrown the mary jane away but I missed the coke).

We thought maybe we had a bad injector so we swapped them out for my stock ones. They had been sitting around a while but they worked when I took them out. Replaced the IAC, too.

Any suggestions? Haven't had a chance to hook T-Link up to it other than at idle which doesn't tell me much.

TIA,
Jim

 

[gmpower6]

Stock heads? If so NO seal on the exhaust valve only on the intake valve. That's where the puff may be coming.

Sean

 

[slipstick]

I have a similar smoke problem at start up. I have eliminated the turbo as the source of smoke by installing a turbo exhaust housing with a blank plate in place of the center section (and turbine) and plugging the turbo oil feed line. I drove the car approx. 75 miles like this and verified the puff of smoke at start up was still present. Also, I have replaced the intake valve stem seals of my stock heads.
At this point in time I do not know the origin of my smoke.
Just thought I would let you know a method for eliminating (or confirming the turbo as the source of smoke.

 

[turbojimmy]

The engine guy is willing to take a look at it but I want to eliminate all other possibilities first. The heads are stock and were rebuilt with the motor. What would tell me if the intake valve isn't sealing? Compression test? Leakdown? I have both testers.

We were trying to figure out how to run it without the turbo so that we could eliminate it as a possibility. We have an extra beat turbo that we could put a plate in. Thanks for the suggestion.

Jim

 

[slipstick]

My intuition is that our problem is from something very specific. I hope you can locate the source of the start up smoke and post your progress.
My car does not appear to smoke after start up and seems to be consuming oil at the rate of 1/4 qt per 1000 miles. It is a frustrating annoyance more than anything.

 

[turbojimmy]

Originally posted by slipstick
My intuition is that our problem is from something very specific. I hope you can locate the source of the start up smoke and post your progress.
My car does not appear to smoke after start up and seems to be consuming oil at the rate of 1/4 qt per 1000 miles. It is a frustrating annoyance more than anything.

I'll let you know if/when we get it fixed. It only has around 75 miles on the rebuilt engine so I don't know about oil consumption. The smoke looks like oil but smells like fuel.

I don't know if the smoke is related to the surging or not. If I fix one we'll see if the other goes away.

Jim

 

[Maltman]

Blue is oil...gas doesn't smoke any color but black. If you smell gas all the time and haven't tuned the car...your probably running rich.

TAs from the late 80's were famous for this crap. Valve guides would be fine, but the "umbrella" seals were crap and allowed oil to pass by and drop down onto the piston when the car sat.

Therefore, you go to start it up and you have a little puddle of oil on your pistons that burns up with ignition. My 88 TA GTA did that every stinkin' time I'd start it up...unless it was within 2 minutes of shuting it off.

I always hated that, but I was too lazy to replace the seals...and I wasn't so sure if it wasn't the guides that were bad given it was higher miles.

Anyway, seals or guides....but I'm betting seals since the guides should be new...and the seals, but it is possible that there not sitting right or they're the wrong ones.

hth

 

[nboost]

Interesting thread as I have the same issue only at start up....keep us informed on results

 

[turbojimmy]

I'm leaning toward valve guide seals myself but this guy has done hundreds of these motors. He did mine and lots of others. When he says it ain't the motor I tend to believe him. I'm running out of other plausible explanations though.

Next we'll run it without the turbo. If I plug the oil feed and run a tube from the MAF to the TB I should be good to go right? It'll be loud but should run I think.

Thanks,
Jim

 

[slipstick]

Jim
I found a 3" aluminum clothes dryer type hose from ACE Hardware to connect from the MAF to throttle body - worked fine for the 75 miles I drove without the turbo.
FYI, I have new valve stem seals and still have the smoke at start up. Also, just to mention, the blank I used to close off the exhaust housing was 3.125" dia. x 1/4" thick. I used a high temp braided (rope type) packing as a gasket and held the plate in place with studs, washers and nuts. Probably, the gasket can be eliminated for the short duration testing.
Good luck, keep us posted.

 

[turbojimmy]

UPDATE

Pulled the valve covers and replaced the valve guide seals on the LH cylinders. They looked okay but since we were in there we replaced them. RH side looked fine and were harder to get at so we didn't touch them.

During the process we found that the #4 plug was totally soaked in fuel. None of the others are like that. We've swapped all of the injectors out already, but I guess it's possible we had 2 bad sets of injectors (stock on this car and my 90k mile stockers). We swapped out that injector for one of the originals.

Also, the cam position sensor is making a lot of racket. Need to fix that, too.

It's not back together and running yet, but I think the wet plug had to have something to do with the smoke.

Jim