new compression numbers

[lil corb]

Aight did a compression test the right way this time, here are the numbers

Cyl. 1= 150psi
Cyl. 2= 140psi
Cyl. 3= 138psi
Cyl. 4= 140psi

Car smokes a little blue after when rpms drop when reving up high, does not smoke during reving or start up. PCV valve sucks only one way which I recall means is good. Valve Cover Gasket and Spark Plug gasket is leaking and I think oil is seeping into Combustion.

Are the numbers good? Cars pulls strong, does not overheat, any ideas? or am I worring too much?

thanks

 

[95blackGsTurbo]

I wouldn't be too worried unless you were going to seriously mod your car. 150 is a good number but the rest of them are ok but getting on the worn side. How many miles does your car have? By the fact that it smokes on startup I'm going to guess a lot. Squirt some oil in the cylinder and recompression test it. If it goes up a significant amount your rings are starting to wear. If not, it is a valve sealing issue.

 

[dr1665]

Squirt some oil in the cylinder and recompression test it. If it goes up a significant amount your rings are starting to wear. If not, it is a valve sealing issue.

Sage advice. Wet test the bi***. Sounds like your numbers are a bit on the tired side. Your engine might pull strongly for now, but I wouldn't expect it to last very long if you keep beating on it.

 

[lil corb]

It doesn't smoke on start ups just when letting off throttle, a puff of blue smoke will happen. The motor has 22k miles from what I was told and it was rebuilt 1500miles ago, again from what I was told. New Bearings, headgasket, headstuds, waterpump, etc. From looking at various parts of the motor I could see new stuff installed like new bolts and etc. the mounts look like they are brand new, etc. I was planning on running a 18g in the future. How long will it last you think in this condition?

 

[Dark_Horse]

Were the rings changed when the engine was rebuilt? If they did not set the ring gap properly or if the piston to wall clearance is too loose you will always have low compression. ~1,500 mile rebuild with low compression is what happened to me. Took apart the block and everything was toast.

Like dr1665 said, wet test. If the compression #'s shoot up, then leakdown test to see where you're losing compression from. I'm betting on rings though.

 

[lil corb]

not sure on rings, going to do leakdown test soon. thanks

 

[lil corb]

BTW I vacuum at 18-20HG if that means anything.