oil smoke during warm-up

I have a Carrera that sometimes smokes(oil burning) upon start up when cold. This usually goes away after a few minutes. The car started this about 2,000mi ago and has 112,000mi. I heard a few opinions about this but the explanation of check valves in the oil circuit leaking could be the cause. Oil is seeping into the sump, over filling it to the cylinders, causing the smoking during initial warm up. What do you think?

With that kind of mileage, could very well be oil leaking past your valve guides. Has the car ever had a top-end overhaul?

Movin,

I seriously doubt that your smoking problem has anything to do with the relief valves, because if it dit you would have a serious case of low oil pressure!

The smoking on startup is one of those problems that many experts have said is nothing to worry about. Some cars do it, and others don't, and it seems to me to be related to the angle the car is parked on, but I can't tell you what angle creates the worst smoke.

Is your case of smokiong one that occurs on every startup, every day, regardless of the interval it has been sitting for? If so, maybe you should check for valve guide wear on the exhaust valves. You can do that by jacking up one side of the car at a time and putting a jack stand under the torsion bar tube. Remove the exhaust valve cover and be prepared for a small amount of oil spillage with a small container and rags or paper towels. As you look for each valve's movement, have an assistand turn the engine over by the alternator pulley nut. Once you see a particular rise to closing, then look for the valve to be lifted off the seat by about 10 mm or 3/8" ... then have the assistant stop turning the engine. Once a valve is in the lift position off the seat, take a large screwdriver and attempt to push the valve stem sideways and look for movement of the stem. If you see visible movement of the stem sideways in reference to the adjusting swivel-foot, then the guides are probably worn. Check all six exhaust valves and expect to take it to a professional for a second opinion if you find enough wear to cause visible 'play' at the valve stem, unless you know an experienced friend to double-check your results. Good luck!

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Warren Hall
1973 911S Targa

My 83 smokes on startup if it sits up for a few days. Also idling on an incline with the nose down.

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Robert Stoll
83 SC
83 944

My 72 911 is parked with a front decline and slightly angled down towards the driver side. It always smokes when I start it. If I park it flat this does not occur.

The puff of smoke that *sometimes* occurs when I start my SC is typical of what others have said happens to their cars. It's a mystery (to me anyway). I thought I'd read somewhere, it had to do with how certain pistons came to rest in a given cylinder after shutdown, allowing a bit of oil to seep past the rings. I used to think this phenomena was time-related. But when I was doing my last batch of servicing, the car sat for 3 weeks. Started right up with not a hint of smoke. Go figure!

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Regards,
Doug
'81 SC Coupe

My 930 smokes on start when it leans to the passnger side...

Here may be a loaded question, but my 72 911T smokes when warming up and high revs. I replaced the spark plugs today and there was oil all around the outside of them. I couldn't get the covers off yet, but there's oil all in there. I tend to think this is a big problem. It's sat for several years and I'm just starting to get her ready.

Any ideas?

Thanks

Mine only smokes when the fan belt slips on startup. And its cold outside. 10-20 degrees.
2-3 seconds of blue smoke. Car was just leaked down max. 3%.

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Cary Kutter
77 Carrera w/3.2
Rennlist #001117-2266
PCA Region - Big Sky

My '88 Carrera smokes at random intervals. I am not so sure that it is an oil problem. I think that it might be an overrich problem. I don't worry about it anymore. I agree with Warren that most experts say some 911s smoke. As long as the engine is strong, don't worry too much!