Replacing my Ap1 motor with a 2004/2005 Ap2 motor, while shopping around I'm asking for a compression test & leak down before I purchase. Now if I'm purchasing a ap2 motor with it out of the vehicle what compression results should I be expecting? Cranking by hand basically. I know perfect is 240psi according to previous threads I've read. Would the results be lower with the motor out of the car cranking by hand?

Thanks in advance,

Shane

 

Yes they would be extremely low, you need the starter to turn over for a few times before you get the readings. It's almost impossible to do by hand using a socket and handle, speaking from experience. best bet is to have them power the starter.

 

...which you can still do with the motor out of the car. So long as the starter is still mounted, they jump a battery to the starter to force it to crank.

I wouldn't trust numbers that come from a seller. Be prepared to bring your own well charged battery, set of jumper cables, and compression tester (which you can rent from places like AutoZone). Along with research beforehand to make sure you know which cable to jump where to kick the starter.

Test it yourself before you buy. A leakdown would be nice, but that takes more time and more equipment (including a compressor). So you may have to make due with just a compression test.

 

He said the battery he used was a little slow. He's in North Carolina, seems pretty reputable from the info I've gotten already, he's also a member on here. Not sure what other options I'd have here.

 

what he said.