Anyone know how to fix oil burning?

[TomO]

I agree that the leakdown test is needed as Honda motors tend to wear Valve stem seals before rings. But sometimes replacing worn valve stem seals can wear out old rings faster.

Sometimes doing both at the same time are required, but the leakdown test will tell which is worn worse.

[brucepick]

I've been dealing with oil loss issues in my '97 Civic, about 230K miles.

A lot of my losses were through the valve stem seals and even the valve guides. It got bad enough that I got check engine lights all the time. I had a couple shops do a compression test and the second shop put a camera scope down the spark plug hole (into leaky cylinder) to look around, found a burned valve. Those scopes can't see the full circle of each valve in the cylinder but he did see the burned one. I decided to trust my rings, after filling the cylinders with Marvel Mystery Oil and after many days they were just as full as when I started. Be VERY careful dipping sticks into spark plug holes to dipstick the oil pool inside!!

So I had the head rebuilt. They replaced four of the 8 exhaust valves and all the valve guides. Of course all the valve seals too (rubber part). No more check engine lights and it runs very smooth after that.

It's still losing some oil. I noticed it on the bottom of the oil pan and suspected the oil pan gasket. However: I've seen it showing up the transmission housing, to the left of the engine. That oil is from the engine's rear main seal, which now likely has 230K miles on it, and 14 years. A pain to replace, but if you also need any clutch work you get access to both when you open up that area.

Early on, I tried many of the usual "fixes" for bad seals. Marvel Mystery oil, also Seafoam (not really for seals), Gunk engine flush (a thinning kerosene type treatment, you idle it 5 minutes to clean out stuff then drain all the oil + refill), and more. No luck with any of them. Also "high mileage" engine oils. No luck there either.

I've had some luck with two different "magic potions" in the oil that helped the rear main seal. Both are from Barr's, the radiator leak fixit people. The first was Barr's Rear Main Seal leak treatment, about $11 per bottle. That stuff worked pretty well. The labeling states in several places that it's specifically for leaky rear main seals. It's pretty thick but I'm sure it also uses additives that help it succeed. For the next oil change I used Barr's Engine Seal treatment, only about $4 per bottle. Helped but not as good; the results didn't last till the next oil change. Next time I'll use the Barr's rear main seal treatment instead.

Hope some of this helps!

[brucepick]

Originally Posted by JasonG

There is another possibility,

You may have carbon stuck rings.

Pull the spark plugs.
Rotate the engine so no pistons are at TDC
Using a funnel, fill the cylinders with kerosene
Let sit overnight.
...
Wiggle the crank a bit.
...
Replace plugs.
Drive for a day or two.
Change oil again.

IMPORTANT: The plugs have to be out when you work the crank. JasonG's post above does have you do it that way but I want to point it out specifically. If you rotate a cylinder that will try to compress air, when it's got liquid in it, you can bend the crank or damage valves. Because you can't compress a liquid, and something has to give.

Also, depending on how much you wiggle the crank, you might have some kerosene come out at you. BTDT.

[user removed]

I advise against a hone and re-ring on high mileage engines. Go with a re bore and new pistons and rings.

Let me explain. The wear pattern on a high mileage engine is a taper from the highest part the rings reach to the bottom of that same reach. Then you have the sharp ridge above the highest contact point above the top ring.

If you hone and leave the ridge and the wear is significant the top ring will break and all of your effort is wasted. Even if you cut the ridge off and then hone you still have the taper flexing the rings on every revolution. Careful measurement of the bores will reveal the severity of the taper, and a crude way to check is to measure the ridge and then just below the ridge. If the difference is more than a couple of thousandths of an inch, then you should bore and replace the pistons and rings as well as main a rod bearings.

If your time is cheap and the ridge is very slight then you might get away with a home and re ring, but in most cases when it is that small you will not have oil consumption problems related to rings. I have heard of people just taking everything apart and cleaning it up and reassembling. They got lucky when the rings were stuck and could not do the job.

Just advice from experience, take it for what it is worth. No need to post nasty responses, to me it is a shame to do 90+% of the work and then not fix the real problem which is a tapered oval shaped cylinder bore with a nasty ridge to slam the top ring which now does not have a wear pattern that matches the ridge.

regards
Mech

[Snatcher]

Like the others say, check the valve stem seals. Pretty easy if you're comfortable with cars and you know how to change a timing belt. Seals alone for a 8v car should be like 8 bucks or so. Thing with honda's are they tend to eat oil regardless but not like you said.
[I'm in no way liable for what you do to your car]
It's fairly easy. Take stuff off that's connected to the valve cover. change the gasket while you're at it. Remove Timing belt. Remove camshaft. remove lifter, use valve spring compressor tool (the one that's made to be used while the head is bolted on to the car. pull out retaining clip pull the valve out with the seal. Change it and to install, do the opposite of removal. Make note on how the cam was placed in. Time it (get it at tdc, two full revolutions from the crank. Let it idle for 20 minutes and check the tension(if it's a manual tensioner, check it regardless) you'll most likely need to re-tighten it. check it every day for a week or so, then after a month it really shouldn't loose tension and you'll be fine.

Use the thickest oil that you can use to reduce oil burn, but it's thicker, which isn't so good for economy.

or go to a junkyard and pull out the same motor and drop it in lol.


Good luck, i hope for the best!!

[mwebb]

i use a pressure transducer in the oil stick tube , sealed to the tube , snap the throttle to WOT , wide open throttle and record the pulses synced on spark from any cylinder -

you will be recording blowby pressure in the crankcase , the leak that gets by the piston rings during combustion

the average pressure must be about 0 in psi or hg or kpa or what ever else you choose - no pressure pulse should be any different than any other

of course
you do not know what i type of -
none the less in an extreme case , such as yours a balloon sealed on the oil stick tube will suffice , the balloon must not expand or blow up at WOT snap if it does , the piston rings leak too much and the PCV valve can not flow enough to relieve the pressure
==========================
intake vacuum , measured at the fuel pressure regulator , vacuum gauge teed in , should be at least 18" 20" is better at hot idle , but more important
there must be no flutter in the needle as in zero flutter , any flutter at all shows a leaking valve -
+++++++
"high mileage oil" is garbage and should never be used for anything except fuel in your heating oil tank -
read the ACEA specifications on the back of the bottle
if it does not show
ACEA A1 B1,A5 B5 good or ACEA A3 B3, A3 B4 much better
do not use it
if there are no ACEA specifications , Unless it has the OEM specification for your engine
DO NOT USE IT, read more at the BITOG forums

one thing dogshnit oil causes is
carboned up piston rings , which may be your problem

[brucepick]

Re. test do not guess -

"none the less in an extreme case , such as yours a balloon sealed on the oil stick tube will suffice , the balloon must not expand or blow up at WOT snap if it does , the piston rings leak too much and the PCV valve can not flow enough to relieve the pressure"

Wow. Super idea. Wish I'd known that back in Feb. 2011 when I had my car's head redone. I think the rings are OK but I'm gonna check them with a balloon or a latex glove stretched over the dipstick tube.

[oil pan 4]

It really sounds like the engine has had it.
It likely has lots of ring wear and cylinder bore taper hasened from lack of oil changes.

Only time I have really seen carbon jamming up the oil rings is in diesels that were not getting the oil changed often enough and were likely being serviced up with gasoline spec oil.

That honda engine is likely so old the valve guide seals are not at all functional.

A quart of oil per day is likely not all due to a head related PCV and valve guide type of problem.

[Frank Lee]

A quart of oil per day is likely not all due to a head related PCV and valve guide type of problem.

I disagree. When those little valve guide seals split the oil pours right past them.

[JasonG]

Frank Lee is right.
We have seen them split in half and fairly fallen off.
Combine that with worn guides and the burn a ton of oil.

Warning on doing the valve stem seals the way Snatcher describes :

Be sure to bring each piston to TDC before you remove the retaining clips.
Drop just one of those valves, and you are pulling the head
Shoving a piece of rope through the spark plug hole will hold the valves tight to the head making getting the keepers back on much easier.