So I had crankshaft pully bolt strip and break off which prompted a mild engine rebuild. I broke my H22 motor down, replaced piston rings, valve seals, all other gaskets and o-rings I came across in the process...now I'm burning oil like a mother f'er. I burned 1/3 of a quart today in 5-10 minutes of idle. Compression is 220-230 in all cylinders. I've read that valve stems or oil rings are the likely suspects, but both were replaced (granted this was my first rodeo regarding those). I know the valve stems were seated well as I was very careful on that. I also was sure to line up the piston rings properly. Not sure what troubleshooting steps to take at this point. Would appreciate some help. Thanks in advance.

 

leakdown will help pinpoint

 

Everything that I've read suggests that a leakdown test can't confirm a problem with valve stem seals...also...after letting car cool a bit, it appears I only burned half of what I thought...maybe 1/6th of a quart. Started reading that until piston rings "set", it's expected to burn oil. Couldn't find anything on "setting" the rings. Just happens over time?

 

The rings should seat in the first minute or two. On the engines I build they never burned oil. Did you set the piston ring gaps to spec? Also, with the h22 engines they are frm lined cylinders and cannot be honed the conventional way.

 

If the valvetrain is all proper and you have solid compression my guess is going to be an improper hone or there are scores in the bores. I'd also recheck the valve seals. That's a LOT of oil to be burning with compression that good.

 

Thanks for the replies guys...

Ring gaps were to spec at the time I put the piston install tool around the piston. Took a little shimmying to get them in, but I imagine no more than anyone else would have had.

I didn't do any honing. Cylinder walls were real smooth...no scoring whatsoever.

Not sure what I'm looking for in rechecking the valve seals (I imagine you mean the valve stem seals as opposed to performing a leakdown test on the valve seat). That they're snug in place?

 

Yeah, as good as your compression is I doubt a leakdown test will do any good, that just tests if it's going out the rings, out the intake valves, or exhaust valves. As reticent as I am to recommend the cans-o-goop you find down Aisle 7 at Oreillys, I don't see how you have anything to lose by trying a bottle of valve stem repair or similar. With that oil consumption a teardown is coming anyway.

Unless...The oil is dissapearing into the combustion chambers? At idle its possible that the head gasket has freakishly failed and is allowing oil into the combustion chamber on intake stroke. What do your plugs look like?

 

I don't see how I could have good compression with a failed head gasket...

Will have to wait until the weekend to take a look at plugs. Then I guess I'll take another look at valve stem guide seals. I used the ones from an Amazon "gasket kit"...I know some people loathe those...

 

confirming that you replaced rings and did NOT hone the worn bores?

 

It will not.
You are correct. A leak down test will reveal nothing as it relates to oil leaking.

Many DIYs(and even some"pros") seem to think so, and this is beacuse they have never built an engine and/or do not understand how the construction of the engine works.



There are no tests(or testers) to find oil leaks. Only clues and vigilance will lead you to the leaks.

Here are some loose rules regarding leaks:

If the valve guides are leaking the vehicle will tend to smoke the worst on first start in the morning. You can pull one or both of the manifolds and look for signs of oil. (there should be none at all.)
If the rings are leaking you can look into the cylinders and look for evidence of "washing" around the pistons. Meaning the area around the outter edges of the pistons will be cleaner than the center.

In either case the vehicle will likely exhibt smoke under hard accel. You can have some one follow to confirm.


With the amount of oil you're losing, Id suspect the rings.

 

i bet new oil control rings never set since there was no crosshatch on the bores.

 

The smooth bores...correct.

This appears to be directly from Honda.


SB618958 #18939

1990-2001 Prelude – Honing Fiber Reinforced Metal (FRM) cylinders 2000-01 S2000

All S2000 and 1990 and later VTEC and SI Preludes have Fiber-Reinforced Metal (FRM) cylinder liners. FRM honing is not required unless the cylinder has deep vertical scratches that run the length of the bore. Cylinders with light colored spots or flaking cannot be corrected by honing and must be replaced.

To hone FRM liners, perform the following:
· Use a rigid hone (not a ball hone) with GC-600-J or finer stones for nonferrous
metals. The honing pressure should be 200-300 kPa (2-3 kg-cm2, 29-43 psi).
· Use an oil type honing oil.
· Hone at 45-50 rpm to a 60 degree-crosshatch pattern.
· Do not stroke the hone more than 20 cycles.
· After honing, thoroughly clean the engine block of all metal particles by
washing with hot soapy water, then dry and oil them immediately. Never use
solvent; it will only redistribute the grit.
· Some light vertical scoring and scratching is acceptable if it isn’t deep enough
to catch your fingernail, and doesn’t run the full length of the bore. (rm,sn)