btungcab87

Because of the amounts of oil being burned and my last battle of fixing the fun car ruled out:

Stem seals
Valves
Timing
Coolant Loss

With the amount of leakage bumped up to 35% in cylinder 4 and 15-20% in the other 3 I decided to pull the engine apart this morning (only took 2 hours, not bad)

I see cylinder wall scoring on the exhaust side and also scoring on the pistons. Looks like normal wear for me on the engine that's had 130K miles on it now, but like always a second look never hurt anyone. Just a recap:

Car smoked out clouds of thick grey smoke on idle and throttle (if anyone says its coolant just leave the thread now, its not coolant), Leak down test showed 20,15,20,35 from cylinders 1-4. Changed out PCV, Stem seals, and checked the valves in the head. Compression range at last test was 178,175,178,175.

Question is, would you run these pistons again? I have the new rings and am ready to install and file them. Just coming from a 2 stroke world where this amount of rub would mean a new piston set. I am unsure if this is normal for a 4 stroke engine.

Also I have a hone that attaches to the drill. My cylinder walls are well within spec still, do these cylinders look like a hone is needed? The scoring on the exhaust side is light enough that my fingernails do not catch.

ezone

If you can't hang a fingernail in the scratches on the cylinder walls, that's supposed to be acceptable.

Scratches in the piston skirts won't pass oil, but deep scratches in the cylinder walls can.

Skirts look scored like it may have been run low on oil and/or run hot with swelled pistons.
This is the engine that was run severely overheated?

Maybe it's got a a manual trans and the engine has been 'lugged' at too low RPM?

Some scoring is average, but to what extent I can't say. Second piston pic looks typical but the other 3 are iffy IMO.
Most of the pistons I see these days are teflon coated on the skirts and still have some wear on them.

Measure clearance of skirt to cylinder wall. If clearance is too big they may piston slap all the time (piston slap while cold is typical and expected though).
Did it do this (piston slap) before you took it apart? If noise wasn't a problem I would reuse them?

Were the oil control rings stuck in their grooves?
If this was a severe overheat, they may have just lost their spring tension and can't seal well.

I would sure hope that filing ring gaps should not be necessary if you got standard bore size rings and standard bore block.

btungcab87

This was the engine that was smoking, never overheated or had issues with coolant. Coworkers car that she has given to me after her and her bf bought a new one.

No noise from the engine. Just severe smoke that ended up being 2 quarts of oil a week as time went on.

Oil rings in 3,4 were so carbon imprinted that the rings were gummy and on top of that I could not separate them easily just now. Upon removal the oil rings have fair amount of carbon build up on the pistons groove.

ezone

The one that quit smoking for a little while after messing with the PCV Valve?

In the pics the rings didn't look really stuck, I didn't know if you already worked on getting them freed up or not.
Do you think the rings were the cause of all the oil smoke?

Ok....Any bearing wear that would indicate it ran out of oil?

No noise is good, that means all the wear on the pistons isn't causing a noticeable noise problem. I'd reuse them (for a cheap out). Same for bearings.

Clean the ring grooves out, slap new rings in, and run it? Sell it?

btungcab87

Had the block honed and installed new rings. Still same damn issue. Bleh time to leave it for a while.and rethink or find a cheap donor engine.

Planning to sell when it's running

ezone

Did you ever investigate deeper into the PCV system (crankcase baffle box) and valve cover breather tube areas?

btungcab87

Yup all cleaned out when I had the top end apart. Going to do another leak down test and see what it says when I get home today.

Question about the valves. I had cylinder 1 at TDC, took the head off and found that the valves in cylinder 4 were loose, I could wiggle them even though they were seated in the head. Wondering if maybe my valves or head is just shot?

ezone

You mean clearance between valve stem and valve guide allows play, or clearance between rocker arm and valve stem tip (valve lash adjustment)?

Valve stem seals hardened and can't flex with valve movement?
Oil return holes in the head are not clogged with sludge?

btungcab87

Valve stem seals are new, oem honda.

The clearance of the valve to the head. Adjusted the valve lash to spec, but noticed that when I had the head off the valves didn't seat tight to the head. A lot of carbon build up but cleaned that up before installing.

Oil return holes are clear and oil flows steadily.