Question about compression test w/ low battery

I just finished doing the motor for the 95 neon, and we went and did a compression test to make sure all was well. The battery has not been charged in a while, including the old compression tests we did with it when the motor had bent valves, so it couldn’t have been too strong. The motor barely turned over, as if the battery was on its last leg.

Anyways… the compression was terrible, ~ 30 across, accept for one that was in the 50’s. My question, with the battery having such low juice, and the motor barely turning over the 5 times for the compression test, is it possible for that to affect the compression test, or would the compression test be the same no matter how fast the motor turned over?

Thanks guys,

–mark

And since I want to use the new smileys… :walter:

I asked 2 people so far, and they both told me it would read really low, so i’m starting to feel better about myself, lol.

my saturn junkyard engine made 0 compression when I tested the compression. turns out the problem was the lack of oil on the rings. a couple drops in each cylinder and I had 185~ across all cylinders. The engine had been sitting so long there was no oil on anything.

yes you need a good batery.

Yup, its true! I did it again with my STi as a jumper car, and it was 120+ across. I did it again, and it was 160. It just has to work the rings and the carbon off the valves I think. Its been a while since this car run.

Woo woo

–mark

Good too see some progress on that thing!

yeah, I cleaned it up TONS. re-tapped every thread under the hood, de-rusted anything, and then re-painted anything that i prepped. Removed the a/c, egr, evap purge, got the timing cover on, and cleaned up everything REALLY nice.

Should run this week.

–mark

Awesome, glad everything worked out well for you. I knew it would live again once in the right hands. So when is the turbo coming into play? :cool: