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Rb25Det Compression Results

juicy3

By juicy3,
in Engines & Forced Induction

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juicy3 Apprentice

juicy3

Posted
Posted

Hey Guys,

Did a compression test today on my r33 and was Pretty happy until the 6th piston (closest to driver)

Here were the results

1 - 150

2 - 152

3 - 156

4 - 155

5 - 150

and then :((

6 - 90

put about 5 - 10ml of oil in there and it only went up to about 93 :((

Not too happy with that

Could anyone shed some like on what might be wrong and ways to go about fixing it??
I do have a video of the tests if they are relevant to anyone?

Thanks Guys
Josh

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https://www.sau.com.au/forums/topic/426387-rb25det-compression-results/
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SargeRX8 Grand Master

SargeRX8

Posted
Posted

Maybe you could be hopeful, somewhat, and hope for a slightly damaged head gasket in cylinder 6. Before pulling it apart you could do a leak down test. That will tell you if its the head or your piston and if it is the head, is it the intake or exhaust valve.

SargeRX8 Grand Master

SargeRX8

Posted
Posted

How does a leakdown test tell you the difference between any of those? Best I can tell all it tells you is that X amount of air is getting out.

If you hear air gushing out of the exhaust you know you have an exhaust valve issue, if you hear air gushing out of the pod filter you have an intake valve leak, if you hear air gushing out through your dip stick or it pops out, then the seals or piston are at fault as air is getting past them and pushing the dipstick out. If the air is leaking from a leak down test where is it going? Where ever the problem is, that is where the air will be coming out from. Its pretty simple.

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