Compression Test Results!

Ok did a compression test, from left to right cylindar readings

140 180 185 185


HUUUM could number 1 be my problem. Its been over heating, would this and the overheating point to a headgasket, like a pinhole leak or something

Generally you want your numbers to be withing 10% of the highest number. The other numbers would have to be 154 for your 140 to be an OK number. So i would say it's definately to low. Now you need to try a leakdown test, to see if it could be leaking out of the exhaust valve, intake valve, or a possible head gasket leak, or even a leak in piston seals.

Edit: For checking this, you will need to remove the radiator cap, valve cover cap, and open the throttle body. When you do the test, put your ear up against either of these, the throttle body for an intake valve, the exhaust pipe for that valve, and the valve cover to see if the rings are leaking into the crankcase, and if the coolant is bubbling, it's a sign of a head gasket leak.

Thats actually the number 4 cylinder, and its the least likely of them all to go bad. 1 and 2 get beat up the most, since they tend to run a bit leaner/hotter. I always toast number 2. Odd. Did you do the test again to validate the results? 180-185 is perfectly normal for a 2g motor however, so thats good.

I have been attempting to help 95ClipseGS-T with his problem, but I am by no means an expert. A little background that he neglected to mention:

He recently blew a headgasket and took it to a shop to have replaced. They removed the head, machined it and did a valve job. The head was then reinstalled with a new OEM HG. After the HG replacement, he ended up with a RM CEL. This was fixed by redoing the timing on the motor. Shortly after, the car began overheating.

I suggested that he do a compression test and the results are what he posted above. How hard is it to screw up a HG install? Is it possible that the RM caused him to blow the HG on just the #4 cylinder?

Oh, also, the water pump was replaced while the head was off.

Just thought that a little background would make it easier to diagnose the problem.

Were the head bolts replaced on it to? Are the head bolts on our engines torque to yield, Kevin? I would think the shop would know that though...

Have you checked for any intermix in the oil pan? Coolant-oil mix?

ok I have ARP head studs put on at that time too. The car started overheating before the timing was fixed.The guy at the shop is telling me to flush my radiator, then we will try something else. WTF why would the radiator have anything to do with the compression in the #4 cyclindar lol. I also did the test like 2 or 3 times to make sure and all read real close to the exact numbers.Im going to take it to another shop to have them do a leak down test then bring the results and the car to the other shop and say FIX IT BIATCH

Do that and report back with your results. Cause i'm stumped on this one and very curious.


Edit: The tech is retarded, he's thinking that flushing your coolant will fix it, but it's overheating because there's probably low coolant, which means that the coolant is probably going somewhere, either the oil pan etc.. And that means that there's a good chance there's a head gasket leak, considering the low compression.. Good luck man

Yea that what me and spyder was thinking, that with the low compression and the overheating issue, its pointing to a headgasket. BUT NOOOO! the tech thinks he did everything right(just like the timing on the first try lol)