I just did a compression test on my evo, just to know where I am with it.

I got 145 across all the cylinders. I believe thats in spec, I think 138 is the minimum, but it seems low.

Since it's not in just 1 or 2 of the cylinders does this mean there is a problem?

 

Evo 8 or 9? Reason I ask is because according to the manuals, the 2 have different compression numbers....

 

Was the engine warm? Battery level? Did you have a booster connected to ensure each cylinder see's the same cranking amps. Also, it is more important that they are all the same rather than a "low" reading. In most cases a problem can be revealed when one or 2 of the 4 are reading low. If all 4 are on the low side, then you may just be seeing normal wear.

 

Evo IX 30,000 miles. Just picked it up a week ago.

Alan, can you post the different compression numbers? Just for informational purposes.


Thats what I was curious about, basically if they are all the same not much of a chance of a blown head gasket, or leaking rings, bad valves... i.e. Car might not be in pristine shape with 160 across the board but should still be ok?

Engine was warm, no booster or anything else special. Just pulled the plugs and disconnected the crankshaft position sensor. I'll be changing my oil this coming weekend as it was on the low side, and it's due for a change anyways. Would that affect the numbers?

Thanks guys,

 

Lack of booster on the battery would have somewhat of an effect. Also amount of crank time you allow.

Consistent numbers across the board are a good sign though.

 

i think it says that they all need to be within 15psi.