So I did a compression test yesterday and got these results -

145 155 165 125

The previous owner did the 1x1 ARP stud method and it's got the rear block oil leak issue so I was going to have the head gasket done but I wanted to make sure I covered all my bases. I did a leak down test with the following results -

Cylinder 1 (145PSI) -found air coming out of the same PCV recirculation hose and the intake, same areas as cylinder 4.

Cylinder 2 and 3 (155 and 165PSI respectively) - did not perform.

Cylinder 4 (125PSI) - air leaking out too fast to get it to 100 PSI so it wouldn't ever fully pressurize. The places I found air coming were - PCV hose connected to the intake and air coming out of the intake (I removed the filter/MAF and held my hand there and could feel it). I heard no air coming of the exhaust, no air coming out the pcv valve itself (or the oil filler cap), no bubbles in the radiator, and no sound out the exhaust. Opening the throttle plate changed the sound of the air coming out as well.




Questions are -

Did I do it right? I used the extension bar down the spark plug hole method.
If I did it right, what does this indicate? Valve stem seals? The valve seating improperly?
Should I check cylinders 2 and 3?

I thought rings for sure at first but since I'm not hearing it in the dipstick I'm guessing that is a no.

Thanks tuners!
Matt

 

intake valves not seated correctly from the sounds of it. How about the first cylinder? just low compression there?

 

Oops, I updated with more results of the leak down test

 

how many miles on that motor bro and how are you reving it.

 

Rev limiter is stock and I've never tracked it or anything. I've only hit 7500 a few times and have never accidentally done the misshift/rev limiter thing either. Mileage currently is 58900. From talking to Jackon Machine Shop and a few other guys it sounds like the intake valves aren't sealing properly so it sounds like I'm going to have to get a valve job.

 

Stock valve springs and retainers w/ 272 cams? This might be the culprit not sure though.

 

that 4th cylinder is pretty low...