Compression numbers?THOUGHTS???

[dohcfiend]

i looked at a replacement motor a few days ago and i came back today and did a compression check.

here are the numbers:

6=150
4=150
2=120
5=150
3=135
1=125

looks like the lowest one is about 20% different than the highest. should i snatch it up or keep looking?

[BMFH]

RE: Compression numbers?THOUGHTS???

Hello All

A cylinder leak down test will tell you more about how good of shape everything is, it is a time consuming process, but you will know exactly where and how much compression is being lost by listening for excaping air and you will have a gage reading showing the percentage of compression lost.

Hope this helps make a better decision.

John

[blk92z34getrag]

RE: Compression numbers?THOUGHTS???

That is pretty low that means you should definately leak down the cylinders. If 1 and 3 are both lower you might have head or block problems...

Don't forget to listen for hissing out of anywhere (oil fill cap, spark plug holes, intake and exhaust...).

EDIT: Sorry for practically repeating what was already said... I'm exhausted and didn't see if there were other posts.

[pepsi_coke]

How efficent would a leak down test be if you have a high mileage motor? Or would that not play an active role at all ?

-Jay

[blk92z34getrag]

You could have a million miles and it wouldn't make a difference. The test will tell you how much your cylinder is leaking and where it's leaking to (by listening for the hissing from the places I mentioned).

[Scott205]

I am thinking since 1, 2, 3 are all pretty low... they probably ran the engine low on oil or coolant, burning that end of the engine a bit more. If you plan on replacing the rings and/or pistons.. sounds like a good one.

[SappySE107]

They should really all be higher than 150 too. I wouldn't get it unless you plan to tear it apart first. It may need rings or a valve job or just a gasket, but something is going to need to be done.

[dohcfiend]

as long as it runs long enough to get out of my driveway for the next buyer i do not care. sorry been slacking on the update. the car that cam with the motor, i am going to flip it and build my engine with the profits.