normal compression readings
parts68
03-15-2006, 08:14 PM
just did compression test on a 95 that dealer said had 2 dead cylinders.
I did this cold(I know warm engine is most accurate but I needed to do this
while some other things were disassembled,preventing me from driving it.)
Lowest I got was on cyl #2 @185 and it looks like no carbon on top of piston.
the rest are all 200-220.
I dont see anything wrong with this except some carbon build up on piston tops.
Im going to do the top engine cleaner/piston soak overnight to try and loosen up some of the carbon.
Ive heard that GM top engine cleaner is made by someone else and can be had much cheaper in that brand.
Any ideas who makes it?
What is normal compression?
FSM says 140-170 but that seems low for over 10:1 compression
I did this cold(I know warm engine is most accurate but I needed to do this
while some other things were disassembled,preventing me from driving it.)
Lowest I got was on cyl #2 @185 and it looks like no carbon on top of piston.
the rest are all 200-220.
I dont see anything wrong with this except some carbon build up on piston tops.
Im going to do the top engine cleaner/piston soak overnight to try and loosen up some of the carbon.
Ive heard that GM top engine cleaner is made by someone else and can be had much cheaper in that brand.
Any ideas who makes it?
What is normal compression?
FSM says 140-170 but that seems low for over 10:1 compression
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