Hi all, I did a compression test on all 4 cylinders. Cyl # 1,2,3 show 220 steady, but cyl# 4 pressures up, but doesn't hold as the needle slowly drops. did it 4 times with same results.

Am I doing something wrong? If not, what else could it be?

 

Probably just the hose connection or valve is leaking. It's a one way valve so that you can manually release the pressure after you are finished with each cylinder.

 

If 1,2 and 3 are good, then my guess is either a valve or rings on cylinder 4, check valve lash on cylinder 4, may just have a "tight" valve. 94

 

It was user error on his part. The pin wasnt sitting correctly on his tester. We did it again and it held at 215.

However, i do need to adjust my valve lash, since im hearing a slight ticking noise