I'm looking at a 91 964 Turbo and called a well known shop with 40 yrs experience to get a PPI done. When I asked about the compression/ leak down I was told on these 964/Turbo cars it wont be accurate, the reading will be all over the place. He also told me Bruce Anderson had a write up on this in Excellent magazine.

So where does this leave me? How do I know the engine is in good shape?

 

I really don't understand why this is true for a Turbo.
Does not make sense. Maybe they can elaborate .
Elliot

 

I've done leakdown and compression tests on 965's and never had an issue. I would like to read Bruce's article though on it.

 

I agree w/IAPorscheDoc. Never had an issue. You could consider sending and oil sample to some place like: http://www.dalube.com/clsinfo.htm. At least that would indicate any likely significant bearing or ring issues, but the leakdown is kinda critical, I would not compromise on getting a definitive result.

 

I would get a compression and leak down test done somewhere else, how else can you verify the compression and condition of the rings, head gaskets, and valves, which could set you back $5-10,000 in repairs.

 

I did take it to another shop and these were the readings I received.

1 125 5%
2 125 6%
3 125 4%
4 125 5%
5 125 6%
6 130 3%

Oh and I bought it

 

Well Done! Sweet! Enjoy!