help with compression test results...

93turboteg

New Member
i searched, but maybe not good enough, so try not to flame me to hard..

i dont know the cylinder numbers yet, im using 1-2-3-4 fromt left to right.. but anyways. in that order my numbers are...

165 - 135 - 145 - 125.

the 165 seems good and 145 can pass by the 135 and 125 worries me... since its not cylinders next to each other, i can rule out headgasket i think...

also, there is oil on the spark plug threads, and really bad on the second cylinder, and there was oil on the threads of the compression tester when i pulled it out...

rings? valve stem seals? help!
 

mirrorimg

Well-Known Member
The oil on the thread is probably from the rubber seals on your valve cover gasket. There are 4 spark plug tube seals which usually get overlooked when doing the valve cover gasket.

The cylinder numbers are 4-3-2-1, the rightmost cylinder(nearest the timing belt) is cylinder 1.

There is A LOT of fluctuation in your results. Did you do it after the engine warmed up? Did you crank the engine until the needle stopped increasing, or a set # of cranks? You should redo the test to make sure you did it right. I gave my motor a compression test before tearing it apart and got 195 +- 5 across all cylinders. I'm pretty sure the MINIMUM compression within spec is either 145 or 165.
 

93turboteg

New Member
ah, i did it on a cold motor, i pulled the main pump relay and all the ignition wires and since it was just me doing it, i just held it for a couple seconds on each, WOT...

ill redo it another day with how you said to do it and a second person..

according to ur cylinder numbers, my 3 plug, the one i said has a lot of oil, its going up towards the tip, like near the gap...

the reason im doing a compression test is im burning a HELL of a lot of oil..

i arleady found leaks from the feed and return lines on my turbo, which will be getting fixed soon, and a slight leak outta the pan gasket, but idk, i dont think those would be enough to burn a lot of oil, maybe the turbo one? but ill redo the test either later or another day..

dont wanna get back into it now since my buffalo bills are playing soon.

but thanks.
you seem to be the one helping me a lot on here, i might just start pming you haha
 

mirrorimg

Well-Known Member
It better to have threads on things like this. It opens up information for others to see.

I was burning a lot of oil (n/a, not turbo) so I'm doing a full rebuild. Covering all my bases replacing my rings, valve seals, and valve guides.
 


93turboteg

New Member
alright ahah, well so far you say not to take those numbers into consideration and just redo it with a FULLY charged battery, warmed engine? was i correct to pull the pump relay and ignition wires off the distributor?

and the oil on threads i shouldnt worry about bottom end things? i was planning on pulling off the valve cover anyways cause im thinking about painting my other one and putting htat one on, ill replcae all the gaskets when i do that..

last queston, if the valve cover gasket and seals leak a bit of oil, will that have a signicant factor in where my oil is going? or just a slight amount..
 

93turboteg

New Member
okay so i redid the comp test on a warmed engine with a friend to help watch the needle.. these are the results..

cyl 1 = 135
cyl 2 = 155
cyl 3 = 150
cyl 4 = 165

cyl 1 def seems to be an issue... piston rings?
 
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