M113 - losing 2L oil/1000Km - rebuild or replace?
 

Hey guys,

My M113 is using or burning a lot of oil. Current mileage is 144,000 Km.

Just did a 1000 Km round trip and my 1998 E430 required 2L of oil to be added. On the way down (500Km leg) and 'low oil' warning came up on the instrument cluster. I added 1L of oil, Elf 5W30 (229.3). On the way back (perhaps 500-600Km later), the same warning came on again. Added another 1L. When I got home, I checked the dipstick and the oil was at the lower 1/3 mark.

I occasionally get a puff of blue smoke on startup, usually after the car has sat for a while. I thought valve stem seals, but every tech I've spoken to says they haven't seen this on an M112/113.

No significant leaks, the ground under the car is bare. However, I haven't inspected the entire engine thoroughly yet.

When running, the car doesn't visibly smoke at all (cats sucking it up?). Car runs and idles well. Even when accelerating hard, there is no visible exhaust.

Mileage is decent - I got approx. 600 Km on about 70L of gas on mostly highway.

When I bought the car in April, it wasn't showing any blue smoke at startup and it got perfect zeros on the emissions test. Consumption seems to have gotten worse since then.

Before I go further, I am wondering what the next steps should be? Could it be anything other than rings/valves? If it is the rings/valves, I am leaning towards buying a used engine rather than rebuilding (cost is about half).

Any advice? TIA.

This is killing me. I love the way this car handles and drives and the chassis is in excellent shape. This car was babied at the dealer since Day 1. However, it seems to have gone 17,000 Km between oil change intervals (as per FSS) on regular (non-synthetic) oil up to about 60,000 Km. Dealer used Quaker State. We don't have the lawsuit extended coverage up here in Canada, so I'm probably on my own as far as Mercedes corporate is concerned.

I wonder why the suit hasn't been filed in Canada. I think I'd offer MB Canada a deal - fix your car and you won't file the class action.

Wow. That's terrible. I'd go over every square inch of that motor to make absolutely certain that it's not leaking somewhere.

However, a leak that large should be immediately obvious. Then again, so should that level of oil burning. The oil does not just disappear though, it's either being burned or leaking out.

Keep us posted. My hope & guess is that there's a leak, but that may be Pollyanna-ish.

It sounds like the piston rings are sticking. It's not uncommon for M112/113's. My shop re-rings about one or two every month to resolve oil consumption complaints. Before we tear them down though, we perform a borescope inspection of the cylinder walls. Every now and then we find severe scoring. In these cases we replace the engine block with a set of fitted pistons.

ILUVMILS - that is my biggest worry, that the rings are toast.

I'm just trying to decide what to do next. try and de-sludge it as best I can and pray, or just get another engine.

I pulled the engine cover (plastic one) and looked around with a flashlight. What I found is some leaking around the passenger side valve cover, just under the MAF. There is plenty of dusty-looking oil gunk there and several of the coil packs look wet with oil. Also some fresh looking oil around the spark plug areas on that side.

So there is a leak.

However, there is absolutely no oil under the car in my garage where it sits all night. So these leaks must be minor. Unless perhaps they leak more under high load and then stop once parked?? :confused:

Also - looked under the oil cap and down into the valve head area and I saw reddish-brown sludge. It wipes off easily with my finger. Looks dirty inside as well. I could post a pic later if that woudl help?

I'm wondering if I should pull a valve cover to see how bad the sludge is. Perhaps I should try some AutoRX or flushes to try and clean the sludge? I know manufacturers state not to use it, but at this point my trust in Mercedes' advice is suspect to say the least.

It kills me to see a beautiful car like this, which has been babied - and I mean babied - since Day 1. I have about 40 pages of records from the dealer to prove so. Service booklet inside the glovebox has also been kept up to date.

And now I'm guessing when I pull the valve cover, it'll be a mess of sludge, slidge, sludge. :mad:

Maybe babying it too much was the cause for the oil consumption as some cars like to be driven hard to seat the rings properly.

Find a stretch of road where you can hit 60mph the do a lot of engine braking to achieve a high vacuum condition.This will hopefully free up the rings more.

300B, Been there and done that but thank you for the suggestion nonetheless!

Interestingly, my leak is identical to that described by this guy here -

http://forums.mbworld.org/forums/showthread.php?t=198556

He has started a poll on it as he thinks it is a common leak spot on M112/113. Who knows, but it's interesting it's the identical area I have a leak.

Similar experience
 

with a totally different engine, so the particulars might not be the same but the concept is.
After I bought my 300E I changed the oil to synthetic (as I always do). The oil consumption started to increase and got as bad as 1Qt in 800 miles-with no smoke or leaking-before it suddenly dropped off to less than a Qt for 3000 miles-where it has remained. My theory is that the synthetic oil set about cleaning the oil control rings which increased consumption and once the rings were clean, the consumption ceased.
Sounds like you switched from the QS dino oil to the Elf, which may be the cause. You might try living with and closely monitoring the consumption for a while before dropping big $ on engine work. In the meantime, check the compression and the spark plugs to see if there is a problem isolated to one or a few cylinders.

If you're at 1L/500km, I bet you'd see some oil fouling on the plugs if the oil is finding its way through the combustion chamber. Before buying a new engine, inspect the plugs and do a compression and leakdown test. Even on new fangled engines, some good old diagnostic work is in order...

Hey John!

Good to hear from you. Maybe you could just run an oil pipeline from Alberta to my garage...:D

Yeah, I've decided at this point to bring it to my local dealer and see if they will help in terms of a leak test and potential help from Mercedes. I've got all my documentation in order and it shows that the engine ran on dino up to 80,000 Km with 17,000 Km intervals - all done at the flagship dealer in Toronto no less.

Failing that, I may try cleaning the sludge out with something like Auto RX. Yeah, yeah I know, snake oil and all that...but this product has some convincing independent reviews all over the web. From Bimmer owners in Toronto, to some members here on the forum. Even on the BobIsTheOilGuy forum, it's getting praise in terms of actually working.

At this point, if Mercedes doesn't help, I don't really have anything to lose by trying the product. I'm as skeptical as the next cynic, but I may as well try this product and see if it can help.

I'll post updates/info/pics as I get them.

Thanks to all for the advice, it's appreciated.

Synthetic oil by itself should clean it out.

Pull the plugs and take pic's, I'd be interested in seeing how they look. Keep them in order cylinders 1-8 so you can see how its burning.

Yeah, I may get some wrench time in this weekend, if I do I'll post pics of plugs.

Hat - it's been running on synthetic for well over a year, good synthetic too. Elf Solaris since April, which is a Group 4 (PAO) oil, made in Germany.

You should see what it looks like inside. :eek: I think a good synthetic with detergents can clean some gunk, but when it is heavily sludged from thousands of Kms of use, I think something stronger is required.

I'm not hoping for miracles either, I'm guessing this engine is toast.

At this point I'd dump the ELF which doesn't seem to be helping the situation and switchover to something more appropriate like Valvoline Maxlife.

http://www.valvoline.com/pages/products/product_detail.asp?product=101

Thats a group 3, I beleive the Elf is a group 4.

10,000 mile OCI on dino oil?? :eek::eek: On an expensive engine like that??

Man, that gives me the willies just thinking about it.