I have a OBD2 LS motor in my EK now, and it is burning a lot of oil..On daily driving, no high reving, im still losing a quart a week...I've narrowed down the problem just a little. A few weeks ago my head went bad and I replaced it, but I discovered that my engine was still shooting alot of smoke from oil..What do you think the problem is and how can I fix it?

 

I will post a copy of a previous post on how to test for the cause of oil burning tomorrow, its too late right now. If I forget, bump.

 

Your head went bad so you had it replaced? Do elaborate on this; it's peak my interest.

I don't know how the head can just magically go bad. Was it warped? Did you have burnt / bent valves? Were the valve seals no good?

If you just had top end work done and it's showing signs of burning oil, take it back.

 

my head has nothing to do with this topic, however I had 2 bent valves, and one valve got so hot that it actually chipped off and a piece fell off of it Back to the problem at hand..what is causing my engine to lose soo much oil??

 

Do a compression and/or leakdown test. It could be anything from valve seals, piston rings or a scoured cylinder wall from any debris/broken valves/etc..

 

Compression test will tell you if you've got a major issue, like "why isn't this cylinder firing?". Leakdown will tell you what's wrong and where. If all you have access to is a compression tester then use it.... and if numbers are low then put a tbsp of oil in the cylinder and retest... if it goes up, rings...

I'm losing about the same amount of oil, compression tests always come out perfect. Did a leakdown this weekend and discovered issues with intake valves on two cylinders and exhaust valves on one cylinder and one cylinder that's well within spec.

A quick "where's the oil going" visual:
Constant blue smoke, more throttle... more smoke. More than likely, rings... sucks

Puffs of smoke on occasion, clears up or spews black smoke at higher throttle. Smokes more when cold. Downshifting to slow the car down and then getting on the gas yield a big blue cloud. Valves/guides/seals are your likely culprit.

"but my car is blowin black smoke!!!"
and you're losing oil? Your plugs/o2 sensors are getting fouled from the oil and the car is running richer. There's just too much carbon in the smoke to see the blue stuff...

 

Ignore any of the posts that tell you to do a leakdown and compression test to check for oil consumption. They are wrong, they won't tell you anything.

When you do a leakdown or compression you are testing how well the engine seals air only. The piston has three rings on it. Two compression rings and an oil control ring. The oil control ring is what keeps oil from getting into the combustion chamber and causing the smoke. You could take the oil ring out and still have great compression and leakdown numbers - actually they might be better because the extra oil would help seal the cylinders. A leakdown or compression test can not tell you aything about the valve seals because they are outside the combustion chamber.

There are typically two areas that cause excessive oil consumption like you describe - the rings and the valve guide seals. There are tests you can run to determine which way to continue troubleshooting. Either way will require teardown if oil consumption is excessive and PCV is OK.

First test:

Have a buddy drive behind you to observe for smoke. Communicate on mobile phones to make it easier. Put the car in third and bring the RPM to about 1500 or so and then stand on the gas (make sure you are on a safe, straight road) until you almost hit redline. If the car blows smoke on hard accel it has faulty oil control rings. Period. I will attach a previous post as to how this happens at the end of this post.

Second test:

Again have a buddy driving behind you. Bring the car up to a decent speed and then downshift it so the RPM are about 5-6000 and let your foot completely off the gas. The engine should be revving high and the throttle completely shut so there is high vacuum in the intake manifold. If it smokes on decel it has a bad valve seal(s). It may take a few second for it to load up and smoke due to the catalytic convertor.

You can try to narrow it down to 1 cylinder by looking at the plugs. Check for any plugs that stand out as different especially oil fouling. If the plug only has deposits on one side of the plug, suspect the valve seal that side of the plug was pointed at. Oil control rings usually get stuck due to carbon build up in the ring lands. You might try adding a quart of transmission fluid (because it has a lot of detergent) rather that engine oil to help free them. If you have a valve guide seal problem you need to check valve to guide clearance or your problem may come back if the clearance is excessive.

Also be aware that if you, say, rebuild the head and the bottom end is pretty high mileage the good sealing head is going to exacerbate any problems with the bottom end so even though it wasn't smoking on accel before, it might now. The reverse is also true if you do the rings but not the head.

One more thing: Oil smoke is always blue, it is never black. Black smoke comes from rich combustion. The 'blackness' of the smoke is free carbon caused by the dissociation of the hydrocarbon fuel in a shortage of oxygen. There is not enough O2 to spare and create CO2 like it would if it were leaner.

This is a technical description of what is happening from a past post:

Hope that helps.


Modified by Scott_Tucker at 12:55 PM 7/24/2006


Modified by Scott_Tucker at 1:01 PM 7/24/2006

 

It seems my car passes both tests. When I downshift to high revs, I see smoke burning from my muffler. When I nail it and vring it up to high revs, the same. More smoke when I downshift though...

 

How many miles are on the engine?

 

about 90k, but the previous owner beat this engine to f***, so the low mileage really doesnt mean anything

 

well thats your problem....time for a rebuild!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by onepoint6i &raquo;</TD></TR><TR><TD CLASS="quote">well thats your problem....time for a rebuild!</TD></TR></TABLE>

I agree, If the previous owner beat the expletive out of it he probably didn't change the oil either. It's definately possible it's got stuck oil control rings and bad valve seals or excessive guide clearance.

It is possible your cat's loading up and that is why you are also getting smoke on decel (this is a long shot) try bringing it up to 5-6k rpm really gently, hold it there for a few seconds (to try to burn any oil off the cat), then let your foot completely off the gas. If there isn't any smoke this time your valve seals may be OK.

In reality if the oil control rings are stuck you're going to have to have the head off anyway so you might as well replace them as preventative maintenance.

 

What exactly is involved in a rebuild, do I have to take it to a machine shop or can it be done at home with simple tools, what do I need to buy? How much will it cost?

 

This is the problem my civic has, I just replace the head, and it smoking...and it seems to fit the criteria of bad rings. if I rev it , put it in 3rd gear and mash on it, it blows smoke out... blue smoke. If I put it in neutral and rev it 3 or 4 times...it starts blowing out smoke. Rings?? WHen I start it cold in the mornings... it doesnt smoke...

 

sounds like me...I am gonna need rings too i believe..A bottom end rebuild is in need

 

Well I put new rings and rod bearings, the car doesnt smoke anymore. So if your car smokes the harder you drive it, and the harder you drive it the more it smokes...it must be rings.

The oil rings were wore down flush with the surface of the piston. The ring gaps were closer together, like they were still compressed. They almost look stuck . From what I could tell, when the car got overeheated, the tiny upper and lower oil retainer, lost their strength, they are much thinner than the compression rings.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lexluther &raquo;</TD></TR><TR><TD CLASS="quote">

The oil rings were wore down flush with the surface of the piston. The ring gaps were closer together, like they were still compressed. They almost look stuck . From what I could tell, when the car got overeheated, the tiny upper and lower oil retainer, lost their strength, they are much thinner than the compression rings. </TD></TR></TABLE>

It is not uncommon for low-tension rings such as those used in Honda engines to collapse when the engine overheats. Was there any carbon behind the rings which may have been causing them to stick?

 

There was some carbon, especially on the bottom of one of the thin oil retainer rings. I guess thats what there called. One on top and one on the bottom, and an accordian band in the middle. There was a little behind the compressions rings also, but not bad. the compression rings were pretty good, 180psi+ in all 4 cylinders. But I put new ones when I replaced the oil rings. I havent checked the new compression, I dont think the rings are seated yet. It doesnt seem to have the overall power the old rings had. It might be the tighter tolerences, I am not sure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lexluther &raquo;</TD></TR><TR><TD CLASS="quote">There was some carbon, especially on the bottom of one of the thin oil retainer rings. I guess thats what there called. One on top and one on the bottom, and an accordian band in the middle. There was a little behind the compressions rings also, but not bad. the compression rings were pretty good, 180psi+ in all 4 cylinders. But I put new ones when I replaced the oil rings. I havent checked the new compression, I dont think the rings are seated yet. It doesnt seem to have the overall power the old rings had. It might be the tighter tolerences, I am not sure.</TD></TR></TABLE>

That was the problem. There was carbon behind the oil control rings which could then not expand against the cylinder walls. Because of this, enough oil would not get scraped off the cylinder wall and the oil would travel right past it (the oil control ring) and into the combustion chamber where it would be burnt.

The reason your rings haven't seated is because you needed to use a bottle-brush hone to break the glaze of the cylinder walls. The cylinder walls need to be rough so the rings will conform to the shape of the cylinders. You might never be able to seat the rings but you can try by going half-throttle from about 3000 rpm to 5500 rpm and then immediately let your foot off the gas and let it decellerate in gear. Do this several times. Gas pressure behind the compression rings forces them against the cylinder wall and on decelleration vacuum draws oil up onto the cylinder wall and prevents it from scuffing or scoring. You may need to do your runs at full throttle since you didn't hone it.

 

I did hone the cylinder walls. I have put about 300 miles on the car, it doesnt smoke, it just doesnt have all the power, well I cant say that, it just seems weak on low rpm's.. almost like I am hauling a heavy weight around. I took it up the interstate today, got up to 80...it runs out pretty good until you go up big hills and it pulls it down some. Maybe its running normal, I know it only has 92hp, but it seemed stronger before. maybe its in my head.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lexluther &raquo;</TD></TR><TR><TD CLASS="quote">I did hone the cylinder walls. I have put about 300 miles on the car, it doesnt smoke, it just doesnt have all the power, well I cant say that, it just seems weak on low rpm's.. almost like I am hauling a heavy weight around. I took it up the interstate today, got up to 80...it runs out pretty good until you go up big hills and it pulls it down some. Maybe its running normal, I know it only has 92hp, but it seemed stronger before. maybe its in my head.</TD></TR></TABLE>

I apologize, I think I mis-read your previous post. The oil control rings may be working well while the compression rings are not seated. That's a possibility but I couldn't tell you any further without driving the car.

 

How long does it take fo rings to seat?.... Maybe I didnt hone the cylinders enough.

 

compression test???

 

I am scared to do one.

 

I'll just say that I"ve heard two methods of seating the rings. One is the easy-slow-low-rev method... and the other is the flog-the-dogshit out of it... allow to cool... repeat a few times... rings should be seated...