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burning oil 2nd gen

12K views 27 replies 10 participants last post by  davedrivesody 
#1 ·
Hi My 04 Odyssey has a little over 222,000 miles on it with original transmission. I was wondering if there was a significant known problems with 3.5 burning oil at extended idling time? Is this normal at this mileage? idling from 5-20 min seems to be recreatable every time. are there any known factors such as rings wearing out oor valves seeping? Or do i just have the case of bad luck. There is absolutely no blow by out of the crankcase and the PCV system is working as it should. Once you drive it hard enough iit will clear up and burn clean until idling in park. Also The smoke that's exciting the tailpipe neither smells like coolant or oil and has a strong smell as if there is plastic, however evidence of low on oil only leads me to believe its burning oil. all of the mechanics I have been to are startled just by the smell. There are no fault codes or drivability complaints.

Please let me know if there are any contributing factors that can cause this.
Thanks
Finnegan
 
#3 ·
I'm at a little over that mileage on my '99 with no problems like that.

One idea though - I know you say the PCV system is working fine, but on mine, a couple of times I had IACV problems. After fixing those by cleaning, I've concluded that the root cause is an oil bath / tar pit that accumulates in the bottom of the intake manifold (which I can only assume is from the PCV system). At some point, this goo migrates past the throttle body into the IACV, causing it to clog, requiring cleaning or replacement.

Maybe you're lucky in not having the IACV issues, or maybe you fixed that without finding the oil bath / tar pit. But you might still have all that oil in there, and maybe under some conditions it gets into the cylinders and gets burned.

If so, you can maybe take a quick look by taking off the throttle body to get a look / feel inside the intake manifold. Or you could just remove it. Very easy to clean the intake manifold thoroughly if you fully remove it. Spec says to replace the intake manifold gasket when replacing, which I did. But it's a metal gasket, and I would not be surprised if re-using it works fine.
 
#23 ·
Excellent suggestion, I too used to lose about a quart of oil every 3 or 4 months until I recently, a few days ago, replaced a clogged PCV valve. As you point out, I am going to try to open the throttle body and see if there is any goo collected there and try to clean it up.
 
#5 ·
This engine is not known for ring wear, but a compression test would confirm that.

The oil appearing at idle indicates that it's being sucked into the engine through the intake system by the high vacuum at idle.

Leaking valve guide seals would be another possible cause. However, check the items mentioned above first. Replacing valve seals would require removing the heads.

Dave
 
#6 ·
Do you ever have to add coolant?
Is it possible that some rubber or plastic trash is stuck to or above the catalytic converter or elsewhere and causing that odor?
Check your PCV valve and also check for suction (engine idling, of course).
Any codes and is your check engine light actually working? (should go on when you first turn the key on)
Are you using the recommended spark plugs? Hopefully not Bosch. Pull a couple of them and look at them, or, if they haven't been changed in over 80k miles, just put in some new NGK or Denso spark plugs as they will most likely be the last ones you will have to install. Pretty good prices on Ebay and Amazon or sometime on sales at Auto Zone etc.
All of the other advice offer is excellent and should be considered.
Buffalo4
 
#7 ·
Thank you Dave, Buffalo4 and all other forum users for your support!!!
I have never added coolant, and the coolant is not milkshake colored. I have recently replaced the PCV valve as it was clogged. There are no pending or current trouble codes. the spark plugs are way overdue as the last record we have is when we bought the odyssey with 90,000 miles on it. The check engine light works and does its precheck before the engine is started and then stays out. The engine burns clean and smells normal when started cold and will only smoke and smell after it has been driven at highway speeds and then idled. I have a good suspicion that its drawing in oil from the valves. I really need the valves adjusted. I also have no record of having the valve lash adjusted. I will start with new spark plugs and a valve adjustment and go from there.

Thanks
Finnegan.
 
#9 ·
Good idea on the valve adjustment. With 220k now, and you got it at 90k, and have not adjusted, you are overdue. I actually doubt that will fix this problem, but in doing the job, you'll be right in there to see if you have other problems.
 
#12 · (Edited)
Good idea on the valve adjustment... in doing the job, you'll be right in there to see if you have other problems.
A little more detail on this suggestion - I still think the issue I mentioned in #3 could be causing problems. When the valves are adjusted, either by you or a pro, the intake manifold will come off. That is a perfect time to take it aside and give it a really thorough cleaning - of the collected tar/oil on the top side of the bottom surface inside the manifold.

I expect most pro's will not bother to clean that. That's just how they normally work; the mentality I've found with most skilled tradesmen :)rockon:) is that the "best ones" (what they pride themselves in, and strive for) are the ones who can get the job done the fastest, and they aim for speed rather than thoroughness. I can't say that's not the best thing for them to do, but that's what I observe. So you may need to be extra insistent that it is cleaned, if you want it to happen. It's really not hard to do.

Glad to hear your TB jobs are ahead of schedule.
 
#13 ·
Man, that intake plenum, with its Helmholtz chambers, does collect big puddles of oil. If you pull off the cover on the manifold's top, you'll see chambers that lead outboard from the center of the manifold. At your mileage, if they have never been cleaned up, I can almost guarantee that they are full of oil and occasionally spilling liquid oil into the intake runner for individual or multiple cylinders.

This is from a 2004 Pilot, but it does illustrate how there are chambers outboard from the manifold centerline that lead to the intake runners. These chambers can collect pools of oil via the PCV system.

Oil entering the intake stream like that, in solid slugs, AFAIK, does not help the piston's oil control ring do a good job. Result may be excessive oil consumption. It's counterintuitive, and I really cannot remember where I uncovered that information years ago, and it is eluding my best efforts at web-sleuthing it to find it right now.

When I clean the EGR passages, I make sure to get rid of that oil. Almost makes me want to install a cheap catch can in the PCV line just upstream from the PCV valve.

OF
 
#14 ·
Thank you Odyfamily, I will take a good hard look, the intake has never been cleaned and my previous PCV valve was completely clogged with oil and sludge. I will clean it and its passages, if that does not work, my only conclusion is that the valve guides are worn out and is destin for a head job at that point
 
#15 ·
Remember, white smoke while the engine is warming up is normal (moisture).
You might even want to try a product to help rings that may be sticking, such as Marvel Mystery Oil added to the motor oil.
Pulling the spark plugs and looking them over might give you some clues.
Don't just assume the valve guides are the problem until you do a thorough checking of other ideas,etc.
A compression test can also be very informative as can a vacuum test. These are fairly easy to do and low cost.
The PCV valve being so clogged can indicate a compression problem (blow-by), and it might just be sticking rings.
Use a high quality full synthetic oil as they seem to do a lot better job of cleaning the engine, etc. than regular motor oil.
After the engine is at operating temp and has been driven, stop the Ody and, with the engine running, remove the oil fill cap to see if there is a lot of blow-by coming out. If so, that usually indicates a ring problem or a clogged PCV system.
Buffalo4
 
#16 ·
I wonder just how much oil is actually being lost. (could not find that info) My 02 with 230k does burn or otherwise lose about a quart in 3000 miles. I mean it's not exactly new...
I did just use some ATP AT-205. I believe at Odyfamilys suggestion. I used a little in the power steering tank and just put the rest in the crankcase once the oil level dropped from the last change. I have to say that it did not make much of a difference so far. Will add a whole pint as soon as it's low from the next change.
Mine does pass smog tests. I think checking and adding oil is just one of the pleasures of driving old cars...
 
#17 ·
The ATP AT-205 is great for rear main seals on the crankshaft, but I have no experience with its use for diminishing valve stem seal leakage.

Every van is different. Our pair of Gen 2's, both approaching 200,000 miles, burn about 20 oz. of oil every 8,000 miles or so. We use Mobil 1 EP.

*sigh* both are due an EGR cleanup. :( More work....

OF
 
#19 ·
In the OP's post #1, he mentioned that blue smoke comes from the exhaust when idling.

Dave
 
#21 ·
It's to the point where sometime soon both heads are going to have to come off due to worn valve guides. The valves have never been adjusted and are clatering pretty good, one day I remember adding 3 quarts of oil at one time to bring oil level into hash marks. either way just doing a valve adjustment I highly doubt will fix the oil burning.
 
#22 ·
...either way just doing a valve adjustment I highly doubt will fix the oil burning.
Yes that's for sure, any more than having a wheel alignment will fix a loose ball joint. :D

Seriously though, removing the valve covers (especially the pesky rear one) to do a valve adjustment would be well on the way to removing the heads. I would pull the heads, replace the oil seals, and then adjust the valves.

I once knew a tech who could replace the valve stem oil seals without removing the heads (small block Chevy V8). It involved injecting compressed air into the cylinders to keep the valves closed. Not sure if this would work on a J35, but maybe something to research...

Dave
 
#24 ·
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There seem to be a few gaskets. Which ones are easy enough to be replaced when opening the intake manifold to clear up goo that leaked from the PCV valve over the years? I guess I would know if I open the manifold but Id like to order the parts before I do that.
 
#25 ·
The only gaskets that you need to be concerned with are the pair of #5's and the single #11.

A few of our Odyclubbers have simply re-used the gaskets with no issues noticed. Me? At the very least I replace #11.

OF
 
#28 ·
Exhaust smoke from leaking valve seals is often seen during or after an extended idle.

The engine intake (throttle body to cylinder section) has its highest vacuum at idle. This vacuum can suck oil into the cylinder through any compromised parts (e.g. valve stem seals, gaskets, etc.)

The sound you mentioned probably indicates that it needs a valve adjustment. This job is obviously also in the valve area, but is unrelated to the smoking.
 
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