I have a 2002 Civic EX coupe 1.7 vtec 150K original miles.

I replaced the head with a rebuilt head. I haven’t started the engine yet

I did a compression test and the results are #1 190 #2 180 #3 140 #4 220. I did the test multiple times according to the information I found on the all-data website for this engine.

I know these readings are weird… 3 out of 4 are too high.

I have checked the belt timing and adjusted the valves multiple times all according to the information I found on the all-data website for this engine.

I have worked on more than a few engines and have no explanation for the high readings

Thanks in advance for any help someone can offer me.

 

lol @ assuming high compression engine... no .... If I was a betting man A it would be a janky/offbrand compression gauge with a analog dial that you are just reading the highest compression number , B you are reading the compression after a few rotations which the difference can make it bounce up in between compression stroke , "10:1" and is rated between 160-215psi depending on condition of motor , C you have soo much carbon buildup on those cylinders its slightly bumping compression ratio, at the end of the day if its not smoking SEND IT and stop thinking about it , E All-Data is **** and has alot of bad info on it and is terrible for compression/wiring/labor times

 

Thanks for your reply.
Two compression gauges have been used to help eliminate the "bad gauge" idea. They both read the same.
The tops of the pistons were surprisingly clean when the old head was pulled. I did very little clean up on the piston tops to make them very clean.
Yes... I did rotate the engine over for several revolutions when doing the test. Everything I read said this was correct. I did remove the schrader valve from one of the tester's hoses but only tried it on #4. The max reading was 150 without the schrader. With the schrader in the gauge hose it read 220.

 

Thanks for your reply.
Two compression gauges have been used to help eliminate the "bad gauge" idea. They both read the same.
The tops of the pistons were surprisingly clean when the old head was pulled. I did very little clean up on the piston tops to make them very clean.
Yes... I did rotate the engine over for several revolutions when doing the test. Everything I read said this was correct. I did remove the schrader valve from one of the tester's hoses but only tried it on #4. The max reading was 150 without the schrader. With the schrader in the gauge hose it read 220.