compression check on '89 corolla all trac

[andrew12159]

OK, Just did a compression check on my '89 corolla all trac sr5 wagon with a 4afe. cyl #1-180psi, cyl #2- 180 psi, cyl #3165-170 psi, cyl #4-205-210 psi. How does this sound? I did the test with the engine cold because of a horrible rod knock. could the high numbers on #4 be because of the knock? Car has 98k on it.

[tashirosgt]

The 1989 Corolla Service Manual gives the acceptable compression for the 4A-F and 4A-FE engines as 191 psi to 142 psi. The 4A-GE is 179 to 142 psi.

(My 1989 Corolla 4A-F engine has all cylinders around 145 psi on each cylinder after 248,000 miles.)

I wonder if one can double check a compression gauge by connecting it to a tire or an air compressor. But I suppose there are things that cause over compression in an old engine. Some one tell us what they are!