smoke on start-up

[leverpuller]

regarding my 1982SC, thanks for answering my earlier thread...the leak down test is where i'm going to start. I've noticed smoking on the same scenerios as some of the other responders. I once noticed some smoking during hard accellerating. It was more like forced smoke thru the exhaust. I was doing a night run, entering the freeway and,the on coming car headlights created the perfect view to see the smoke flowing from the rear...The odd thing is, this little car run's great, Its never let me down,or stranded and it's still has great midrange torque. Removing the engine seems like the wrong thing to do. usually smokey engines need repairing but ...... leak down test here I go. What is a leak down test anyway?

[ianc]

You can find more info with a search, but in a nutshell you pressurize the cylinder at TDC through the spark plug hole. The tester has two gauges; one that measures line pressure and one measuring press in the cyl. You adjust the line press to 100 psi, and the other will be something less; the higher the better. The beauty of this test is that you can hear where the leak is. Out the breather hose is rings, through in the intake is an intake valve, and out the tailpipe is an exhaust valve. Good luck,

ianc

[RWebb]

you realize that smoke on starting is common and usual for a Porsche flat 6, right?

[Lorenfb]

"The beauty of this test is that you can hear where the leak is."

ianc

Ridiculous statement! In most cases you'll never hear anything.

[Gunter]

Originally Posted by leverpuller

regarding my 1982SC, thanks for answering my earlier thread...the leak down test is where i'm going to start. I've noticed smoking on the same scenerios as some of the other responders. I once noticed some smoking during hard accellerating. It was more like forced smoke thru the exhaust. I was doing a night run, entering the freeway and,the on coming car headlights created the perfect view to see the smoke flowing from the rear...The odd thing is, this little car run's great, Its never let me down,or stranded and it's still has great midrange torque. Removing the engine seems like the wrong thing to do. usually smokey engines need repairing but ...... leak down test here I go. What is a leak down test anyway?

Rebuilding the engine is the right thing to do; the people behind you (and air quality) will appreciate it.
Smoking during running is different than smoking on start-up.
Compression/Leakdown test will determine how bad the rings/valves are worn.
If you like the car, and have some concern for the environment, you'll feel much better after a rebuild when the engine stops smoking and burning oil.

[azasadny]

Are you running Marvel Mystery Oil fuel improver or anything like that in your fuel? That could explain the smoke... do you have oil leaks that sit on the exhaust, then burn off when you get the engine hot? Sounds crazy, but these two things could cause these symptoms...