Compression reading

[Tony]

Took a compression test on my M-135 GMC engine.

First reading and then squirted oil and took the second reading..Are these readings ok ? or must I do some engine work?

Cyl # 1st reading 2nd Reading with oil squirt

1 125 140

2 115 125

3 115 120

4 130 136


Thanks,

Tony




5 121 139

6 135 135

 

[clinto]

Looks ok to me for a typical low compression gas engine, but what does the TM call for?

 

[Tony]

the manual does not state any specific compression spec..It does state that 30-40 lbs difference in the total is not a comcern

The increase in compression after the oil squirt, is telling me something,,Should I be concerned?

 

[gringeltaube]

Nope. It's telling you that your rings/cylinders are still OK.