Oil consumption despite ring job

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1998 CRV with 100,000+ on the clock started burning oil 1 quart per 700 miles. I pull the spark plugs and see tops of pistons 1 and 2 wet with oil. #3 and #4 pistons are dry. Also, I don't have a smoke plume from the exhaust pipe after starting the engine after an overnight park nor any smoke when I pull away from a stoplight. Alright, it doesn't look like the valve stem seals, which incidentally were replaced 3 years ago. There are no oil leaks I can see on the engine.

So I had the indie shop change my piston rings with originals from Honda. There was also some wear on the conn rod bearings,so these got changed as well. I myself measured the ring gaps after inserting the new rings squarely into the bores using the pistons to push them in, and they were within spec as per the shop manual. So I assume the bores are not well worn. Cylinder walls were glass smooth. No scratches anywhere. The rings were installed correctly as per the shop manual I had. Shop didn't do a cyl hone, as they thought honing would increase the bores slightly. After the engine was put together with new head gasket and oil pan gasket, she's purring like a kitten. The oil level stayed steady for a few weeks but after 700 miles, the oil consumption has reappeared. Same rate as before - a quart every 700 miles. I changed the PCV with a Honda original but still no dice. Why would the oil be good at the start? If the bores are more worn than I thought, wouldn"t the oil consumption be bad from the start and improve as the rings got seated? Any thoughts on what to look at next?
 
Walls were glass smooth--good, but did you still see crosshatch on them? Or where they shiney in some spots with cross hatch in others?

I don't think pushing rings in, and measuring the gap, is the proper way to measure. Actually I've never heard of that method, although it makes some sense... Problem is, I don't think it will register on the low areas of the cylinder wall, where the wear occurs. And it requires tight control over the gap itself. Where did you put the ring gap when you did this? on the major or minor thrust surface? or 90 degrees from that? I'm not sure if it matters, but am curious... Also, did you push the ring down halfway the bore?

How do the plugs look now?

Oh: how long have you run this for, after the re-ring? takes a while for rings to seat.
 
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It could be a lot of things including a poor job of honing the cylinders, improper installation of the rings, or you're barking up the wrong tree and the valve guides are the problem. Drive it a thousand or so miles and see if consumption tapers off maybe the rings need more time to break in.
 
I was always told to hone cylinders to "break the glaze," otherwise it would burn oil prodigiously as the rings would not seat. Yes, you are removing metal from your cylinder walls, but this is made up in the honing by the cross hatch pattern which will allow rings to seat and control the oil "slipping" past the rings allowing it to burn in combustion.

As far as measuring the ring gap the way you did, that's the way I was taught.
 
Anything is possible, but rings are generally not the reason for oil consumption on Asian engines. Its usually clogged oil return holes on the piston making the oil control ring non-functional. The piston oil return holes need to be drilled out, removing hardened carbon deposits. Then simply put the old rings back or add new rings. The rings don't really wear unless you have 300k+ Even then, I didn't see anything unusual, crosshatch had little if any streaks on the few honda and toyotas I've been involved in teardown. (we are talking about oil control, not compression which is another discussion.) Worn valve seals are also a common source of oil consumption, Asian all-aluminum engines don't dissipate heat very well, cook rubber seals after a while.
 
*slaps head* Ok, I was confusing measuring bore wear with measuring ring gap. Makes perfect sense to measure gap that way. Duh. Sorry for that off-tangent.
 
I always push new rings down the bore with the piston to check ring end gap and as far as I know that is the accepted method of checking end gap. Before installing new rings in a used bore, the use of a glaze breaker is critical as installing new rings without deglazing the bores will usually result in the new rings not seating correctly. Cylinders will wear bell shaped from bottom to top so the bores should also be checked for taper and out of round before deciding to install new rings or to rebore the cylinders.
 
Originally Posted By: berniedd
Cylinder walls were glass smooth.


No cross hatch visible? That is your problem. I would have measured and honed them.
 
The 97-8 CRVs also had issues with burnt intake valves from what I have read. Do you know that the head is in good shape?
 
You did okay with checking the ring end gaps but did you do it at the top, middle and low parts of the bores?

Its a poor mans way of checking bore taper but it works fine. You must break the glaze with a hone so the new rings can seat properly, a flex hone will do it.
The by the book way is measure the piston O.D. and the bore I.D. in 3 places in the bore after busting the glaze then the ring end gaps the way you did it.

As someone posted you might have bad guides or stem seals, did you redo the head?
Did you get enough distance between the ring end gaps on the pistons especially the 3 piece oil control ring?
 
Originally Posted By: Trav

You must break the glaze with a hone so the new rings can seat properly, a flex hone will do it.
The by the book way is measure the piston O.D. and the bore I.D. in 3 places in the bore after busting the glaze then the ring end gaps the way you did it.


+1 this ^^
 
for all re-ring jobs: you must break the glaze with a hone. Glass-smooth means rings aren't seating and sealing properly, and oil will definitely seep past the rings into combustion chamber.

You need to pull the engine apart and redo it.

Q.
 
Originally Posted By: DrDusty86
drive it like you have stolen it to seat the rings.


Definitely worth a shot before tearing the engine apart again. You can do it in a lower gear so as not to risk life and limb and of course, a ticket. Keep an eye on the oil and engine temp so your next post isn't about a blown engine.
 
+5 or whatever on the braking glaze/glass smooth issue.

There had to have been some crosshatching. It's very rare that I find an engine that has worn out it's iron liners to the point of being totally smooth. I tear down engines with 300+ on the clock and you can still see crosshatching. But even without a rehone it'll be very difficult to get those new rings to properly wear in.
 
Did you run a good bore gauge that reads in .0001" through the cylinders ? If not you have no idea how much out of round or taper there is. An engine with that many miles is not going to be a candidate for a simple rering job. Spring loaded or ball hones only follow whats there and in most all instances make things worse not better. As already stated you can't just put rings in without honing. The cross hatch and the grit of stone used is very important for rig breakin.
One other thing, cylinders after honing should be wiped clean with a paper towel soaked in WD40. When the paper towel comes out clean then you are ready to install the piston and rings. You can clean with soap and water all day and think you are ready, then try the WD40 and see just how dirty it still was.
 
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Originally Posted By: demarpaint
It could be a lot of things including a poor job of honing the cylinders, improper installation of the rings, or you're barking up the wrong tree and the valve guides are the problem. Drive it a thousand or so miles and see if consumption tapers off maybe the rings need more time to break in.


Cylinders were not honed.
 
Honing the cyls is key, but it is a messy job as you need to wash the cyls after honing.
Proberbly why the shop elected not to do it.

Also, some brands of aftermarket rings (like Hastings) accommodate out of round cyls better than others.
 
If the ring grooves on the piston are worn too wide, the ring can float up and down and will pump oil up to the combustion chamber. Checking ring side clearance is often overlooked during rebuilds, but it's just as important as the other measurements.
 
who eats these type of job? original post suggests that OP is essentially dictating what the shop is doing aka he is taking the full responsibility?

who did the initial diagnosis? who suggested the rebuild? what is the warranty on the rebuild?
 
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