i understand if a cylinder is bad (psi) then you put a cap full of oil in it and try again, so what does the oil do? just a question thx

 

If the pressure goes up considerably, then you know that it is the piston rings and not the valves/guides.

The oil will coat the ring and provide a better seal which raises the compression.

 

how much psi is considerably to much? becuz mine is 180 across the board. i just want to do this to see if all the rings are worn out. 180 seems still to low.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TypeR0186 &raquo;</TD></TR><TR><TD CLASS="quote">how much psi is considerably to much? becuz mine is 180 across the board. i just want to do this to see if all the rings are worn out. 180 seems still to low. </TD></TR></TABLE>

It depends on the gauge; if the gauge has a lot of volume before the 1-way valve, the measured compression will be lower. Test your gauge on another car to see if 180 psig is low.

 

When you did your test was the motor warm and was the throttle open? A warm motor gives a higher and more realistic reading than a cold one.

John

 

the motor was warm and WOT, followed cspeed how to. my brothers gsr got 175psi across. im assuming the gauge is correct.

 

Your compression should be fine, since it is consistent at 180 psig. Your gauge just reads low.

 

Yeah, 180 is fine as long as all the cylinders are within 10 psi of each other.