compression on d16z6
 

I'm looking at buying a d16z6 from a guy on the board. He did a compression test on it and said 150 135 135 150. Anyone know what the specs are for compression on this motor? Or if that compression is any good?

that seems a little low but still good

wow, that's hella low. prolly a head gasket problem between cyl 2 and 3. IMO, those numbers suck. look to rebuild it.

These numbers are poor...and unfortunately I too was very interested in buying this motor.

My motor was tested for compression and the results were 180-183-180-160. After changing the spark plug in #4 cylinder, it was back up to 180. But I'm still burning oil.

The seller said it ran strong and has taken good care of the motor. If the numbers are really this low, he would have to really push the motor for it to perform.

Is there any possibility that the test was done wrong? What conditions affect the results. Cold motor?

there are no conditions that affect the comp numbers... they should be hella higher. the throttle should be kept wide open, that's all.

as a matter of fact, I think the threshold level published in Haynes/Chilton is 130 psi. 130 psi basically designates a dead motor. it's junk... time for a .020 punch, new rings, bearings, general cleanup work, and a reworked head.

:cry: the hunt for a good z6 continues.

well, you're gonna rebuild, no? so buying a junk motor is no biggie? I'm prolly gonna be getting a junk motor to play with.

This z6 was going to be a replacement for my current z6.

warmer engine will yield higher compression numbers

i have a good z6 in pieces right now and junk z6 in my car :cry::cry:

Stock compression is 184....
Sorry to say....but that motor is pooched.

Did another comp test...warm engine....WOT....which i didn't do last time. 180, 180 170, 160. So engine isn't pooched....still runs strong....was just interested in gettin some numbers so i could tell the buyer.

looks like i was wrong ...

you want to look at the difference across the cylinders mroe than a 10-15% difference motor is toast....and do the test with throttle WO to let max air in......

so what is it that would cause cyl 3 and 4 to be lower?

could be headgasket, rings, or valves... etc

I'm a little confused by this statement...you take the plugs out to run the test. Therefore, there is no way for a plug to affect the test.

I can understand if the tester is not in there tight but to change a plug and have your tester read different #'s just isn't possible.

FYI - I just did a test on my Z6 last night just for comparisons sake.

185-180-190-195

I'm sure the numbers can be more consistent if I took my time but I did the whole test in less than 10 minutes.

wow HAPPYD16 :D that's some good numbers

It'll be a lot happier when I run 10 pounds through it :)