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View Full Version : NO smoke but 60 psi compression across the board? SR20det redtop

filluptieu
09-04-2010, 08:23 PM
I have a s13 redtop with 60 (+/- 4 psi) in all four cylinders. Strangely enough it does not smoke at all and idles just fine, but when full boost kicks in, which is at 7 psi (stock) I dont feel the complete pull from the car. could it be head gasket? or valve seals?

Thanks for your input guys and gals!
I LUV MY S13
09-04-2010, 08:31 PM
hows the oil level?
filluptieu
09-04-2010, 09:40 PM
Perfect, right in the middle of the dip stick. i just replaced it as a matter of fact. does that mean that the exhaust or intake valve seals are shot? because if it were the head gasket it wouldnt be all four cylinders right?
Z33dori
09-05-2010, 09:48 AM
do a leak down test.

it i will help you determine where you comp is bleeding out from. Possible Intake or Ex valves
KoukiMonsta
09-05-2010, 01:45 PM
Perfect, right in the middle of the dip stick. i just replaced it as a matter of fact. does that mean that the exhaust or intake valve seals are shot? because if it were the head gasket it wouldnt be all four cylinders right?

yes this is correct. i once had a crazy issue like this. but mine was ~100 across. and leakdown was like 20,60,20,60(%)....didnt make any sense, pulled the motor tore it down and dont see anything too bad...

hopefully a leakdown test will give more conclusive results for you.

my plan is for new rings, valve seals, and a few other nicks n nacks.

get back w/ results!
brndck
09-05-2010, 02:11 PM
do a leakdown and doublecheck to make sure your cams are installed properly. if one is a tooth off the valves may not be seating when its supposed to be compressing.
I LUV MY S13
09-05-2010, 03:15 PM
Perfect, right in the middle of the dip stick. i just replaced it as a matter of fact. does that mean that the exhaust or intake valve seals are shot? because if it were the head gasket it wouldnt be all four cylinders right?


well reason i asked is because if you were low then there may not be enough oil to seap through valve seals, Head gasket, rings etc.

Now if it were the head gasket it doesnt necessarily mean it will or will not affect all cylinders. It could be a small ridge that warped or a whole left side etc. Best thing to do is a compression leakdown test then go from there
filluptieu
09-05-2010, 04:29 PM
I want to do one but I dont have a compressor unit and im sure shops will charge an arm and a leg for it. Is there a tutorial on how to make sure the cams are in correctly? The car drives fine, just no top end... And I did check the timing on the chains and its correct. ill add a video of it idling.