Cold compression test?

[92Rustang]

How much of a difference will I get in ta cold test compared to a warm test. I did the test with the intake off and a broken valve spring so I could not start the car and warm it up. I know that a warm motor will better seat the rings, but I had a wierd reading.

1 160
2 175
3 175
4 175
5 145
6 150
7 150

Wet

1 150
2 175
3 175
4 175
5 160
6 160
7 175

I find it wierd that that the drivers side is worn more than a passenger. And number 1 compression went down on the wet test?

Know before I added the top end I and never removed the valve covers. With cobra intake and basic bolt ons I ran a best of 13.6 @100 mph and 13.80's all day. I would not think if I had this compression problem the car would run so good.

[PKRWUD]

Those numbers are very inconsistant. I'm suspicious of the gauge. There is no way that a cylinder will lose compession by adding oil. I also find it odd that there is so much cylinder/ring wear on one side and not on the other. I would recommend borrowing a quality gauge from someone and trying it again.

Take care,
-Chris

[exgmguy]

I agree. Oil will always raise the number unless you have a wasted valve. Usual 5.0l compression numbers are around 160 psi.

[92Rustang]

Thanks guys I figured something was wrong. The gauge I have is new and it is a ATD cylinder compression gauge. Anyway I got my springs today and will try and install them tomorrow. I will do another test once I get it running. Thanks for the help guys.