964 compression test results
 

Cylinder psi leakdown
1 190 5%
2 195 8%
3 190 5%
4 195 8%
5 198 8%
6 195 5%


Are these numbers good, or are they the beginning of the end of this 964? It is a 93 with 107,000+ miles.

:)

It's not even the beginning of the beginning for your engine.

-Andy

If you are really worried about this, don't! These numbers are fine - actually a little better than fine. The most important factor in a compression test is consistency between cylinders. A good rule of thumb is to have no more than 10% variance between the cylinders. You are looking great in this regard with about a max of 4% between 1 and 5. Good cylinder leakdown readings should be below 8%. You are on the high end here but that is by no means "the beginning of the end". You've got many, many miles before you'll need a rebuild. If I were you I'd just drive and not worry about it. After all, what else is there to do in Del Rio! I spent a summer there in 1983 doing an Air Force training program. It was a pretty sleepy place back then. Merry Christmas. <O:p</O:p

I think 1% to 3% hot leakdown is ideal. These numbers, especially bundled with compression results are acceptable.
Oil consumption rate would tell you more about necessity for top end rebuild. Is that info available? I would not assume because you have acceptable compression and leak down that you are not in need of valve guides.

Not trying to scare you, but I bought a non running 3.6, which was supposedly rebuilt. I had to pay for a complete rebuild again. Proceed with caution.

Doug

After that many miles, producing those numbers means they were well maintained miles. This would indicate proper driving, oil changes, and warm up cycles. I would say its unreasonable to find any better numbers on a 110,000 mile engine.

The car is immaculate. These numbers are from a car I'm considering buying.

I'm moving to CA this summer so I know I'll have more choices out there. I don't know if this is the best time to buy though. Have you seen house prices in CA!

The compression numbers look darn good. The leakdown isn't spectacular, but certainly not anywhere near a deal-breaker situation. They are consistent, that's the main thing, and you don't know how accurate the testers gauge was either. Higher than 8% and I'd start to do some more homework....

The leakdown numbers are fine. I would concern myself more with where the leak is occuring.

Also, was the motor warm, hot, cold? This also plays into the equation. If you pay for a leakdown, and the shop/mechanic does not tell you where the leaking is occuring, kindly ask for your money back.....

Cheers

Compression and leak-down tests
 

I had a friend help me doing compression-tests on my old 2.7. The compression on all cylinders was 9:1 and it came straight up, it didn't need the engine to turn several times to get there... My friend was wery impressed by this, but this is by no means a leak-down test, what is the difference?

And if the compression on all cylinders is even and good, can there still be problems?