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Leakdown/Compression tests

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Old Jan 24, 2016 | 03:43 PM
  #1  
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mdkrp
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Burning Brakes
 
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From: AZ
Default Leakdown/Compression tests

I would appreciate some help please:

What exactly does the leakdown and compression test results tell me when I am evaluating a 911 for sale? How do I use this to make a decision about the status of the engine?

Also if the test results are acceptable/good, then does it give me any reassuring info on status of head studs (if no rebuild has been done yet)?

Thanks for any insight.
Cheers
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Old Jan 24, 2016 | 06:53 PM
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Jherriott
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Full disclosure... I'm no wrench.

Having said that, for me I feel the only thing the leak-down test does is show the condition of the rings as the valves are closed during the test. I would imagine the head studs would need to be in good shape for the test to be satisfactory. An excessively "oily" chamber may also help improve the numbers even though there is a problem.

I think oil consumption would be the better indicator of valve seal/guide condition.

Hopefully some more experienced voices add to the thread.
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Old Jan 25, 2016 | 02:29 PM
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mdkrp
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Thanks Jherriott.
Appreciate the insight. Let's hear from more "gear heads" as well.
By the way, you and I were both looking at same silver 3.2 from VA last year. Hope you are enjoying it. Looked to be a nice driver.
Cheers
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Old Jan 25, 2016 | 05:06 PM
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Jherriott
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Ah! Thanks brother! I really am enjoying the ride. She's in great shape, yet not so perfect that I am scared to drive the hell out of her

I have some exhaust mods sitting in my shop waiting for spring!
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Last edited by Jherriott; Jan 26, 2016 at 08:32 AM.
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