lemonade

I test drove a 79' 930 today that looked and drove very nice. The PPI revealed that the compression was between 101-110psi across the board and the engine started and ran very well. Now, the engine would release a small puff of smoke on start up (normal), would not smoke at idle or during unloaded revving or while on boost. However, after the boost and after letting off the gas the car would emit some serious clouds of smoke. I tried it again and again with the same results. Is this a valve guide issue or does it seem turbo related?

Best,
David

PorschePhD

What was the leak down? Typically smoking decel is caused from bad guides or seals. In most cases the exhaust guides are shot in these motors. They get pounded with heat.

The other things it *could* be, oil scraper ring, piston, or turbo. I would suggest a leak down first and see where that comes in. It may tell you all you need to know. Everything but the turbo would show up in a leak down if there is a problem in one of these areas.

notthd

I know I have had a few turbo cars that would puff on start but not again. Since it smelled like gas I was always told it was related to the accumulator and not a big issue. Since serious clouds appear at lift off I would think more internals than turbo. When my 87 was pushing 180K miles on it it would smoke under heavy boost and at startup, yours seems oppisite... I look forward to what others think.