mschafer71

My 88 with 74000mi smokes occasionally on start up and valve guides and/or ring wear is most likely part of the problem. The nature of the horizontal layout of our engines also contributes to light smoking on start up. The most important point is to assess the condition of the plugs. If they are fouling up quickly and your oil consumption is high without obvious leaks you should probably start considering some internal work being done. 20-50W and not filling over half mark on the dipstick also seem to help my car.

Ellsworth Wente

I have had the same problem on my 87 with 126k. some time ago I read either here or on Pelican about letting the car idle for the 15sec or so it takes for the oil tank to fill back up after driving before shutting off the ignition. I just watch the dash oil level guage until it floats back up to midline, then shut it down. In theory this lets the oil pump push most of the excess out of the engine and back to the tank before turning it off. FWIW I've found that doing this eliminates the starting smoke puff about 90% of the time. Just something else to try....

mamoroso

My car (88 120k) has exaclty the same problem. Occasionally there is blue smoke coming out of the exhaust. I use the car everyday to go to work. It does not happen all the time.... sometimes it's in the evening coming back, sometime it's in the morning after having sat all night.
The plugs have been just changed and they were in great shape. Leakdown and compression tests were OK. Mechanic (Jim at Eurowerks here in Charlotte... recommended by PCA) said car is in great shape...
I have learnt to live with it. The only drawback is the smell...

sschmerg

Loren:

I am going to respectfully disagree with your assessment re synthetic oil. Based on the evidence and studies I have read, synthetic oil protects the engine better than a conventional oil ever could. There is certainly nothing to indicate that it performs worse than a conventional oil, as you suggest. There is no "time will tell" on this issue...synthetic oil has been used in consumer applications for about thirty years now, as Mobil 1 hit the market in 1973-74 worldwide (no affiliation).

The risk then, it seems, is in not using a synthetic oil. Of course, one must perform a cost-benefit analysis to determine whether the extra cost of the synthetic is justified.

-Sean

Lorenfb

All my Porsche shop customers tell me that switching is not a wise move.
These guys have been in the business 20+ years. The older engines were not
designed for synthetics. Also, why risk heat probelms on a air cooled engine
because of the synthetics. The long term effects of petroleums are well known
for air cooled engines.

"Based on the evidence and studies I have read"

What evidence & studies? I'm sure these were done on air cooled 911 engines
run long term, not.

Cost/Benefit analysis:

Cost >> 0, oil premium cost, repair costs - potential shorten engine life vs known
engine life
Benefit ~ 0

Cost/Benefit = infinite

Dave Thomas

And yet PORSCHE NOW RECOMMENDS SYNTHETIC FOR ALL APPLICATIONS. So you're smarter than Porsche.

Loren's ability to be a complete *** = infinite.

Lorenfb

All most can do is name call!

lewis9113.2

Why not just use a blend......'best of both worlds' I would have thought?