Itoyota

So, i have major compression leaks in cyllinders 1 and 2 ... 50 and 75 psi.

Before i tear her apart, how can i test to see if it's the valve or rings for sure. Will a leakdown compression test prove the rings are bad? Couldnt it possibly be the gasket, or the valves?

cormel

Are you noticing any other problems with your rig? Oil have any milky substnace in it or antifreeze have any oil it it? Any excessive white smoke coming out the tailpipe? put some heavier weight oil in the bad cylinders and do the compression test again, if the compression goes up significantly most likely it is the rings. If not then it is the exhaust valves

eric-the-red

A leakdown test will tell you where the loss is; rings will leak into the crankcase, valves into the intake or exhaust manifolds and headgasket into the cooling system, or adjacent cylinder

Itoyota

no oil in coolant or vice versa, what pisses me off is that i just did a HG. The engine has been completely rebuilt and it's doing this. It was all done right, i just don't see what the compression in all my cyllinders is low apperently. 125 was the highest! Other 22re are getting 180 out of their's. WTF! the head has been milled 3x so it should be tearing through tires not rings!

TNRabbit

Who did your rebuild/HG and how long ago/miles?

ovrrdrive

Shoot about a teaspoon of oil in each cylinder and do the test again. If the compression goes up its rings, if not suspect the valves.

It's not 100% accurate, but it will give you a better idea...

Itoyota

ive done the oil in the cyllinders before i posted this thread .. and it went up average 25 psi between both cyllinders... but here is my question

The engine was rebuilt 30 K miles ago, the headgasket done about three weeks now. And the top pressure is cyllinder 4 w/ only 125. Now i have heard that this is low for a 22re and am wondering if it has anything to do with the rebuild. I had the cyllinders bored and bigger pistons put in as well as a new forged crank. SO! here i come to my point.
If the cyllinders all react the same way to the oil test jumping 25 psi /ish. does that mean that i dont have to rebuild again?
Painstaking work im sure you all know.
One more thing, this rough idle ... didnt happen till after my HG!! so maybe it was mechanical or assembly error on my part?

Itoyota

anyone with any ideas, please shout them out. I don't wanna tear the head off ... and then get lost with the problem.

Here is the plan .. ill check the vacuum of ea. cyllinder .. that's what the machine shop that f^&*ed up said to do. If the results are low ... rings.
Ill tear her apart, and need to know opinions here.

WHAT IS THE MOST RELIABLE WAY TO REBUILD OR BUY THE BOTTOM HALF?
i don't want it to due 2yrs down the road, no ÅÅÅÅty parts. only quality, and im not big with bottom end brands or block rebuilding parties.

scrid

Make sure the valves aren't too tight. This could easily cause your varied compression pressures, and rough idle. I like to test each cylinder by making sure it's on TDC compression stroke, and slowly add air pressure through the spark plug hole. If you hear air leaking past the valves usually you will hear it through the intake or exhaust manifold. If you hear it coming from the neighboring plug hole then it's probably a headgasket bown between those cylinders. Start with the worst cylinder first.

Itoyota

Oaky, so ill gap the valve screws accordingly. So, then you set the engine to tdc for number one. Then, you add air how?
I have a compression gauge .. but that doesn't blow air, even if i connect it to a compressor i don't know if that will work?
last, you said what would happen if its valves or HG, but what would i hear if it's rings>?

Itoyota

and by the way, still looking for the best brand lower end money can buy. Other than toyota of course.

DudeBud

you need to pull the valve core out of it. just like a valve core on a valve stem on a wheel

Itoyota

k, then just pump air into it like normal ... k, that's what i figured. You wouldn't have any strong background with bottom end rebuilds?