Compression test results! 0-60-90-180

[Spoolin4Ever]

Ouch this sucks bad!

I thought I had an injector died, I have no CEL, but I had the CEL before when heat soaked injector pulse. I had an oil burning problem because of the oil return line clogged a little, so I would seafoam frequently, I was getting ready to fix the oil burning problem with a high heat hose.

Well I noticed the car was kinda slow, so I seafoamed it (actually I used MMO as always). TOok it for a drive, still not faster. I filled it with premium and a little MMO in the gas which usually works great.

Took it for a drive, still kinda slow "owe well" getting late went home.

Next day driving it to work I noticed about halfway there that it was missing.

I figured it was the injector on cylinder number 2 (because before with the cel on heatsoaked injector I disabled injectors and number 2 was the culprit).

Well I decided I better do a compression test to see if that could be it. Turns out cylinder #2 has 0 compression, cylinder 3 has 60, cylinder 4 has 90, and cylinder 1 has 180.

Could this be a jumped timing belt or do I probably have some burnt valves?

Also I did a head in which I replaced one bunt vlalve 20K ago. I used brand new stock head bolts, I never re-torqued because I thought with stockers you don't have to.

Currently not using any coolant.

One other thing is that for many of these miles, the coupler that holds the air filter to the turbo, it was off part way, so lots of the time I was sucking unmetered air and running lean, during THAT TIME< it did use lots of coolant, I'm assuming really hot in the combustion chamber and head. But since I fixed the coupler and refilled coolant, it hasn't used any. So did I weaken my valves running hot or could this be jumped timing?


Anyone have an opinion with this type of results? 180-0-60-90

It runs like it's runnning on 3 cylinders basically.

 

[delta448]

That 180 is pretty high for stock compression pistons in a 1G, I do suspect timing is off. However, it is almost impossible that you'd get 0 anywhere and not have a bent valve, hole in a piston or other major mechanical problem.

Do check your timing, but I imagine you're still going to have to pull the head to fix this.

 

[olddsmer]

Put a little oil on top of the pistons and do another comp check.
See if your numbers come up. Do a leakdown test after that.
That should tell you if you are going to have to pull the head.
That zero number does not sound good.

Good Luck
Regards
Greg

 

[400hp93talon]

Im betting its a jumped timing belt....if the cams are off enough it could make one show zero and all the other cylinders would show strange numbers too I doubt you have a hole in a piston or something seriously wrong but I could be wrong.

 

[92AWDHX40]

Those numbers dont sound good, time to pull the head.

 

[400hp93talon]

Those numbers dont sound good, time to pull the head.

Might as will do it to get rid of all the what if's and find out for sure instead of playing the guessing game.

 

[SpawnedX]

Try a different compression tester first.

 

[Spoolin4Ever]

Is it at all possible that if I re-time the timing belt, I could come out with no bent valves? (Assuming it jumped timing?. If it is possible, I will look at resetting the timing belt. If not at all possible (if you are sure there has to be at least one burnt valve or piston for these compression results, I will probably just wait till spring to mess with it).

Is it POSSIBLE to reset the timing and not have a burnt valve or piston? Or does that ALWAYS indicate a burnt valve or piston with these results? Anyone seen similar and it was just the timing belt and it didn't bend a valve?

 

[delta448]

If you correct the mechanical timing and repeat the compression test, you will have your answer.

I honestly think you have a least one bad valve on cylinder 2, but if the timing was off during the compression test I can't guarantee it. Who knows, maybe you're packing 8.8:1 pistons in your bottom end and just forgot to fill out your vehicle profile.

 

[keltalon]

Those numbers dont sound good, time to pull the head.

I agree! you won't really know until you pull the head migh as well go ahead and do it because with those numbers the head will have to come off anyway. It could be another burnt valve, blown head gasket, broken ringland or perhaps a hole in the piston. Sorry to hear please that your car is down please let us know what you find. Some people get upset and down in the dump when this happens and post their issues on the forum and never post the finding of their issue or whether they were able to fix the problem or not.

 

[Spoolin4Ever]

Well it's stock 1G pistons...

No coolant burning or mixing with oil

I'm pretty sure it did jump timing, looks like I didn't torque the tensioner bolt tight enough probably.

I was just curious if it's at all possible that it is just the timing off and could it have those results without a bent valve (possibly).

I will reset the timing first and try another compression test before pulling the head.

I will probably wait till spring... Since most everyone is saying I will need to pull the head, and not one person has seen timing jump and have zero compression in one cylinder and still have it NOT have a bent valve.

 

[ramsack]

If timing is off then all four cylinders will suffer bad compression, it's not like there's a belt and a cam for each cylinder.

 

[delta448]

If timing is off then all four cylinders will suffer abnormal compression, it's not like there's a belt and a cam for each cylinder.

180psi of compression is pretty high for a 1G. Standard OEM compression is 165ish for the 7.8:1 CR pistons, with the service limit at 120ish.

 

[ramsack]

Who cares about the actual number as much as the difference between the cylinders? If it's the same tester used on each cylinder I would give two shits if my compression tester read 120 as long as my car operated correctly and I didn't have crazy blowby. A leakdown test is the real test on condition, not seeing how high you can get a gauge to read after repeated crankings. Maybe he had someone swap in a non-turbo 4g63 and it's blown to hell...multiple things to consider, but to sit here and pine on why one cylinder is at 180 and that's too high when the others are 0, 60, and 90 is pointless.

 

[delta448]

...multiple things to consider, but to sit here and pine on why one cylinder is at 180 and that's too high when the others are 0, 60, and 90 is pointless.

I respectfully disagree. In my opinion it is not pointless. To me it is a clue as to what his problem actually is.

A reading that high indicates one of four things to me:
1) He didn't do the test right.
2) His engine has higher compression pistons and the bottom end is now completely fubared.
3) The cam timing is misaligned such that cylinder 1 has all 4 valves timed to act as intake valves, and cylinder 2 has them timed such that the valve heads are now embedded in the piston or combustion chamber
4) A combination of any two of these.

I do not wish to argue further, and I respect your difference of opinion.