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Leakdown Cold vs. Hot

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Old Dec 13, 2009 | 04:09 PM
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Default Leakdown Cold vs. Hot

I bought a used 2000 LS1 with roughly 60k on it. I have it on the stand now and just did a leak down to see if there were any serious issues.

All but one cylinder have roughly 15%. One is higher, roughly 20%. There is some leakage through the exhaust valve. I also had a very high reading on another exhaust valve but I douched it with carb cleaner and its number came back up. The cleaning did not work on the one that is still high. So, I am hoping that this might just be some carbon build up.

With all of that said, how much improvement should I expect to see if I were to run this test with the engine warm? Would I pick up 5 - 10%?


Let me know what you think.
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Old Dec 13, 2009 | 06:25 PM
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mine did the same thing when i did the leakdown on the stand. most of the loss was by the rings cuz they haven't seen oil in a while but two were out the exhaust valve. i just chocked it to everything not being run in a while or possibly the lifters not bleeding down all the way enough for it to seal.
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Old Dec 13, 2009 | 07:14 PM
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So did you ever re-test once it was back in the car and warm? what improvement in the numbers did you see?
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Old Dec 13, 2009 | 07:26 PM
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na sorry i just dropped it in my stang this weekend don't even have an ignition controller for it yet.
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Old Dec 14, 2009 | 01:15 PM
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Anyone else have experience with this??
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