S4 N/A rebuild..low compression and no start

JustJeff · 08-27-2012, 12:22 PM

I haven't been over to the car since posting this, but shouldn't compression be higher than 60psi regardless of whether it's turned over yet or not?

JL1RX7 · 08-27-2012, 02:07 PM

What kind of compression checker are you using? I have heard that unless you use a rotary specific one you don't get accurate readings. Now whether that would 90 PSIg from rotary one to 80 PSIg to no rotary is a matter of one's opinion. Since the gauge is reading pressure it shouldn't matter what's producing that pressure. Anyway just some food for thought.

Getting strong even pulses seems to be the deciding factor more than not. It could be the seals haven't "set" completely and a little ATF or oil might help them along.

need RX7 · 08-27-2012, 03:19 PM

Quote:

Originally Posted by JustJeff

I haven't been over to the car since posting this, but shouldn't compression be higher than 60psi regardless of whether it's turned over yet or not?

Rebuilds usually start off kind of low, especially with used housings. It should come up after running for a while.

I'm not sure if 60psi is 'normal' though.

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08-27-2012, 02:07 PM	#2
JL1RX7 Rotary Fanatic Join Date: Feb 2008 Location: Front Royal, VA Posts: 487 Rep Power: 18	What kind of compression checker are you using? I have heard that unless you use a rotary specific one you don't get accurate readings. Now whether that would 90 PSIg from rotary one to 80 PSIg to no rotary is a matter of one's opinion. Since the gauge is reading pressure it shouldn't matter what's producing that pressure. Anyway just some food for thought. Getting strong even pulses seems to be the deciding factor more than not. It could be the seals haven't "set" completely and a little ATF or oil might help them along.