4.3 Compression

[jdtower23]

Looking at a used 4.3....'95....took a compression test today....didn't write down the exact #'s....highest was 180....all others were 155-170 except for one that was only 135....didn't want to bother the guy to do anymore tests since he was a 3rd party...

Is the 135 cylinder a major problem? I actually have another set of heads if it may be valve related....

Any advice would be appreciated....

Thanks

 

[brunolund]

Re: 4.3 Compression

you'll need to do more tests to determine why low comp., put a few squirts of oil in that cylinder. if comp comes up, it's the rings. if not, it could be valves or a head gasket. i'd doubt it was a head gasket, cause i'd think it would be way low then. if it is the valves, put that cylinder at TDC on compression stroke, and pressurize the cylinder with air. you should be able to figure out if it's going out the exhaust or intake valve. just be careful, the piston may get driven down rotating the crank 180 degrees, along with all the pulleys.

 

[180shabah]

Re: 4.3 Compression

....didn't want to bother the guy to do anymore tests since he was a 3rd party...

It's not your fault he chose to represent the seller. He took on the responsibility, so there is no need to feel like you are bothering him.

Continue testing until you are satisfied.