ginch

I'm sure I know the answer to this however would like your collective knowledge. I bought my 93 C2 3 summers ago. Had a compression test done when I bought it and came up strong. I was told by the service manager that if the compression tests were good that doing a leak down was not neccessary. Fair enough. First porsche for me so I didn't question that although I know better now. The car always smoked a little upon start up. Again, told this was normal (which I confirmed with several other 911 owners). Fast forward to today. Car runs strong, uses approximately 1 litre for every 2000 km's ( which I'm told is within spec??) however the car smokes every morning when I start it (and again a bit 9 hrs later leaving work). When warmed up and driving it doesn't smoke however it bugs the hell out of me that it does this upon start up. I'm assuming its worn valve guides that are causing the smoke but don't know for sure. The car has 51,000 miles and again IMO runs great. Do I spend the $5-10 thousand getting a top end rebuild or live with it? I know you cannot answer that for me but I guess I'm asking for some advice. What would you do?

Thanks in advance!

Derek

JasonAndreas

The next time you park the car overnight, let the engine idle with the transmission in neutral for 30-45 seconds before you turn off the ignition.

gchristofi

When I decided to go rebuild route due to worn valve guides, the smoke effect was very different to that which you describe. Mine would only smoke when very warm and at idle, any throttle or not fully warmed and the smoke would clear. It got to the point it was embarrassing at red lights so I decided to rectify. As I understand it, worn valve guides often exhibit this behaviour so I would guess your issue is different.

As Jason says, Idling in neutral to allow oil flow back to tank may clear the smoke. I'd take your type of smoke over the issue I had. At least it clears up once you set off. For 5-10k I'd try to live with it unless it got much worse. JMHO.

springer3

How full are you keeping the oil tank? If the level gage goes close to the top, you risk some sloshing getting to the intake system. The calibration on the gage is stupid, IMHO. You need to be near the red zone during normal driving. Fully warmed up and at idle, the gage can touch the thick line at the top, but should never go into that region. I used to get a puff every now and again. It stopped when I cleaned the intake and found the PO had over-filled.

ginch

Yeah the oil level is on the upper edge of the guage when fully warmed up at idle (not in the red zone however). I will try the idling for a minute or so after stopping. Maybe that might help. Would a leakdown test reveal whats going on?

BTW is there a how to on cleaning the intake myself or is this something a shop needs to tackle?

Thanks for your help fellas!

Derek

Indycam

Drop some oil . Get the gauge to point at the low end when the motor is hot .

If the smoke is coming from oil getting past the rings while the motor is sitting turned off ,
that's not really a bad thing . Your cylinder / piston / rings are "happy" to be well lubed .
Better to be a little on the wet side that a little on the dry side .

tbennett017

I also suspect too much oil. The dipstick is more accurate, but I run my car at the 3-o'clock when fully hot (showing about 9 on the temp dial) only.

I think you're overfilling, but use the dipstick to be sure.

ginch

I just find it embarrasing however when she smokes when I start it. I do believe my oil level is too high. I think I will dump some oil and get the intakes cleaned out!

Derek

Indycam

Its not a flaw , its a feature !

ginch

But seriously though, if the car doesn't smoke when warmed up does that mean that the valve guides are not the culprit? If the valve guides were shot the car would smoke all the time?
Derek

springer3

Leakdown test will show a engine wear, which can correlate to oil smoke. You can have low leakdown and still have oil smoke.

Look for Garrett's DIY on changing the oil sender o-ring. That is the best how to on getting the intake off. It is a big job. There are 10 rubber boots, all of which need to fit properly and seal. There are reports of vacuum leaks afterwards. There are a host of "while you are in there" projects: oil sender O-ring, spark-plug wires. Why not get the two PS pump O-rings. While that is off, why not rebuild the pump.....rubber hoses.....

Indycam

I can't think of a way for the valve guides to leak in a way that causes smoke only on start up .

ginch

Sorry its been a while getting back to this thread but the info provided here turned out to be great. By letting the car idle for 40 seconds after driving the car fully warmed up basically stopped any smoke upon start up. Thanks for the advice fellas!!!

sghost

My mechanic told me this is perfectly okay and the car will burn a little oil when warming up. He even mentioned the new 911s smoke when started. I'm new to the Porsche world myself, so take it with a grain of salt.