B16, B18, B20
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By foxtuning65
#184687 I got a gsr motor in my hatch. I just had the bottom end rebuilt in April of '08. Today i tested my new compression tester out and got a reading of

1-205 psi 2- 155 ish 3- 170ish 4- 200ish

I was told that a head gasket could cause compression test numbers to be very down. Is this my problem? The car runs fine until i pop vtec then it gets hot sometimes. It also blows coolant back into the resevoir when i beat on it a little bit. I am going to replace the head gasket either way. But would the head gasket cause low compression numbers?
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By teal_dx
#184713 it could. If so it may be leaking between #2 and #3 cyls. Definitely #3 for sure. Your symptoms describe compression from the cyl leaking into the coolant passages which push coolant into the overflow. Then you have air pockets in the coolant which causes overheating.
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By Greasedmonkey
#184714 Valve needing to be adjusted will cause lower numbers as well.
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By foxtuning65
#184725
Greasedmonkey wrote:Valve needing to be adjusted will cause lower numbers as well.


I am going to do it all this weekend hopefully. I just could not see my rings being shot. I am definitely going to put a new head gasket on with arp studs this weekend. Then ill retest it and see where i am. I just wanted to make sure that this is also a symptom of a blown head gasket.
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By teal_dx
#184734 It could just be a bad seal. I've had that happen and the HG was cracked between cyls 2 & 3. Another time the HG was fine, just had a slight leak. I replaced it anyways.

Be sure to heat cycle & re-torque the ARP's properly. :thumb:
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By foxtuning65
#184740
teal_dx wrote:It could just be a bad seal. I've had that happen and the HG was cracked between cyls 2 & 3. Another time the HG was fine, just had a slight leak. I replaced it anyways.

Be sure to heat cycle & re-torque the ARP's properly. :thumb:


Yeah i was just checking on it tonight to make sure i do it right. :thumb: