Out of curiosity I hooked up my compression tester today to my healthy 1990 944S2 Cabriolet and found the following:

Mileage: 134,371
Test: Engine at operating temperature, dry test
Cylinder #1: 191 psi
Cylinder #2: 189 psi
Cylinder #3: 186 psi
Cylinder #4: 194 psi

The engine pulls well and I'm happy with it but it seems everyone else who has posted results on this model engine gets 210+ psi in each cylinder. Does this just mean my engine is wearing down? 134k doesn't seem like a TON of miles on such a well maintained engine... What kind of effect would this have on horsepower do you think? I assume the only thing I could do anyway would be a rebuild, which I won't be doing, but I am curious nonetheless what others have to say.

Thanks!

 

Sounds fine to me really

 

They are excellent ,You couldn,t ask for better at that mileage.

 

Those look fantastic.

 

I am not an engine guy, clearly, and this car has been running so well lately its starting to make me paranoid, hence the unnecessary checking and worrying haha. I should drive it instead of trying to find issues lol. Thanks all!

 

they are really good results particularly as all the cylinders have comparable compression results.

 

What are the reference values for all the 944 variants regarding the compression results ? Is there a table or something similar ?

 

In my further research I have discovered that the absolute values are not very valuable because there are far too many variables to be able to compare accurately. The more important part is that all the numbers are within a small range, which mine happen to be. It would appear that if one is concerned with the engine needing a rebuild a leakdown test would be preferred. Even then though you are dealing with relative values (in that case percentages) which are not easily compared against any sort of benchmark.

That was what I have gathered...

 

couldn't have put it better Ron.

 

good results. what you are looking for is that the numbers are close to each other which the are.