So I went on a roadtrip portland > LA. On the trip the oil light came on. I thought huh that's weird so I stopped at an autoparts store and oil was at "min" on the dip. So I put in a quart of mobil1. Thinking perhaps the dealer messed up and underfilled it. Drove another 500-600 miles the low oil light comes on again. Sure enough close to min again. WTF? The exhaust tips and back of the car is fairly sooty. What the heck could be going on. Is there any possibility that this won't be a hella painful issue? I'm so disappointed. Y'all know I have only had the car for a month or so.

Any input would be very appreciated.

Thanks

HT

I would naturally say it's fairly normal, but then i saw you were missing a zero on that number there. I have to fill up a half quart or so every five thousand miles, but 500 does mean something is wrong.

Pop the hood, make sure you don't have a massive engine leak? Check for soot and dirty crap that doesn't belong; if it's caked on the engine or anywhere in the engine, you've got a problem. Head gaskets tend to go out easily on most, if not all w202's, and older mercedes in general, contribootin' to the majority of smaller engine leaks. In other words, lets hope your head gasket is only the problem lol...

Good luck

There is no oil leaking that I can tell. The tailpipe and back of trunk is quite sooty. Wish I wasnt 1000 miles from home. So a leaking head gasket would cause the engine to burn oil, or leak it?

Sorry to hear this. Your story reminds me of being out of town when a mass air flow sensor went out on my car - ruined my weekend.

Best of luck to you....remember all will work out.

I'm not an engine mechanic, so my knowledge may be limited; i'm going based on my own experiences myself and/or knowledge that i have researched online. But a leaking head gasket would more likely than not lead to leaking oil into the engine bay. Small, but definite. My car has a leaking head gasket too right now.

The m113 e43 in our C definitely burns oil, as does most AMG engines, ESPECIALLY if you are using Mobil1 0w40 oil. So in other words, burning oil is natural with our cars, but it should be nowhere as much as with your situation.

Do you have pictures of the tailpipe? If you have a friend to videotape or to watch, go to an empty street. From a dig, floor the car. If you see blue smoke come out of your exhaust, that's burning oil right there. And that shouldn't be happening. Worn piston rings perhaps, IF blue smoke is coming out.

I notice no smoke from the rearview. I hope I can get home drama free and just keep topping it off.

High oil consumption under certain conditions is normal. mine will burn 1qt every 10k mi in normal driving, but then can get as high as 0.5qt in as little as 200mi if track driving.

Normal hwy driving shouldn't result in high oil consumption EXCEPT if you haven't done much long distance driving in a long time.

I would be looking for a leak first. Most common places are at the back of each of the rocker covers. the other thing to look for is block breather hoses (there are 3 hoses, the 2 smaller ones block up at the rocker cover fitting).

Both are simple fixes, If you can't find any leaks then I wouldn't be worried about a one-off high oil consumption, if it does persist though then it's worth looking into.

That would explain why I have to add a quart every 2-3,000 miles.

Gets annoying after a while.

Hmm, well I have been driving the **** out of it. Good food for thought. I will still do my due diligence but just knowing that lots of WOT may be the cause lifts my spirits a tad. Thanks for the info.

1 quart per 500 mi even on a AMG motor is too much. You either have an external gasket/seal leak, which you would have noticed on the ground or you can smell oil burning after you park it. If not then its the value seals or oil rings are going away. Check for blue smoke on start up or when you back off the throttle on the freeway. How many miles are on it?

If the motor was leaking that much oil you would know all about it when you park overnight.

What car you driving on this trip.

Inexpensive things can cause oil consumption. They're inexpensive if you can do the work. Check the oil cooler. The o-rings are known to fail. Oil will run down the block, coat the undercarriage, and leave the back uber sooty. Check the valve cover gaskets. Although, a quart in 500 miles is an Exxon Valdez sized valve cover gasket leak. I must be getting old. The Exxon Valdez was over 20 years ago.

If a few valve guides on the intake side have worn out then you’re actually passing most of that oil down the exhaust. Bad intake guides create a vacuum that sucks oil from the valve train area, down into the combustion chamber. Short of a diesel, you can’t actually “burn” that much oil (32 ounces in 500 miles). "Burning" synthetic oil is ESPECIALLY hard. The oil usually goes out the exhaust. That much oil flowing out the exhaust will kill the O2 sensors very shortly. They don’t live long in an oil rich environment. Dead O2 sensors should give the car a lousy idle. The cats don't play well with oil either. The next time you need a quart and the engine is very hot – have a look at the primary cats. If one (or both) are glowing orange, that’s an indication the oil could be passing through the exhaust. In that case, the tail pipe should be damp (and if OBDII is functioning right - a CE light should be on). If valve guides on the exhaust side are bad, the crankcase will be pressurized, and you’ll probably blow a gasket (although not a head gasket). The same is true for rings. Bad rings will cause increased oil consumption AND pressurize the case. Remove the oil filler cap while the car is running. Is a lot of pressurized air coming out?

If I had to make an interweb WAG, I’d say oil cooler seals. They see pressurized oil and can loose a lot if the seal is bad enough. A professional diagnosis would involve a look underneath (you can't hide an oil leak that passes 2 quarts), followed by a leak down test. The leak down will point to the guilty suspect. If you're still in SoCal, pop into Mr MB Motors (5557 Reseda Boulevard # A, Tarzana, CA 91356 Phone 818-708-8086). That's the best indy I know of. He'll diagnosis it for a cheap price AND get it right the first time.

Hopefully it's a cheap fix and NOT the reason the previous owner sold it.

Yeah the car just doesn't seem to be leaking underneath the engine and the back is very sooty. Currently it's running like a top. Revs great, pulls hard, idle is great, the engine sounds great.. It's really vexing. We are heading back up to Sacramento for a few days. I will poke around. Hopefully the problem will not progress to a more advanced stage but going through that much oil just can't be good. If it is going out the exhaust that's going to be costly if I fugg up the emissions equipment. Ok well I really appreciate everyone's input - it helps to have your ideas as starting points for figuring this out.

how many miles do u have on the oil, and what oil is it?? over used oil will burn very easy and will slipp past the rings too.

Are your valve covers leaking?? I had this issue a little while ago and was burning oil ( I was able to smell it). Resealed the valve cover and BOOOOOM no more oil smell or leak.

I never had to top up with any oil on my C43!
Is it because I pus-y drive my car most of the times and when the devil in Mr. Jones comes out then drive like a thief?
However I never noticed my car burning oil!
Is it good or bad not burning oil?

I think that the sooty deposits on the back of your car indicate that you've got oil running through your combustion chamber in some fashion and coming out your tailpipe. (may or may not be completely burning). The air turbulence at the back of the car deposits the small particle or droplets there. In the old school we called it burning oil and that was usually rings or valve guide seals. MarcusF has some good advice IMO.

I've never had to add any oil to my C43 between changes and I check it regularly. I get it changed once a year, or at 4-5K miles. Mobil 1 0W40. The oil has stayed very clean in between changes (light color, no burnt smell). I've been pleasantly surprised by the C43 in this regard. I chalked it up to fine quality parts, metalurgy and machining. I've wondered about those cast-in silicon-aluminum cylinder liners, but heard of no problems in that area.

I once had a SBC ZZ3 crate motor. Brand new, and it burned a quart every 500 miles. That thing sounded like a diesel when it started up cold. It was supposed to be a premium hi-po crate motor, but it was a POS!!!

OT - When are you going to be in Sacramento?



I would be more than happy to buy you a beer and discuss cars.

Yr oil consumption sounds a bit heavy. I'm using 2 qts in 3000 miles or so but I've also got what looks like a valve cover gasket leak and some leakage from a small transverse crack on my sump plate. Will sort these out shortly.

Pretty sure hes there right now, Hoontastic is a real nice guy. You would be fortunate to have his company

@ justin - thanks dude you rock but I already jetted home.

and thanks to 503 for the kind words... i just drove back today. We came back a day early because of work crap. Ok, so the car is definitely not leaking oil that i can tell. I could find ZERO evidence of drips. The under carriage seems dry and the ground underneath has revealed NO spots of oil. The car is also running extremely well. The tailpipe while blackened from soot is not caked with "wet" oil.

When i check the dipstick the oil is still brownish clear but with some blackened sooty particles and has a slight smell of fuel.

I had to put in about 3 quarts of oil during the course of the trip from Portland > Sac > LA > Sac > Portland. I imagine it needs some more but I just got home and am in lounge mode now. I have no check engine light. The car idles awesome. Runs awesome and gives ZERO indication that there is any problem other than the oil consumption.

My ml430 which weighs about half a ton more (and thus works hard given my foot) in the course of 35k miles has burned ZERO oil. So something is definitely wrong with the c43 but its a mystery. I hope I can somehow diagnose this thing without racking up the hours with my indy shop.

503 maybe we could meet up and you can give it the once over. I'm not expecting much but you ARE way more familiar with the car than I am at this point. Anyway - again thanks to all for your support and ideas... we WILL figure this sh_t out!

More than willing to help, give me a call

I add a full quart about every 2k miles. So, I don't think 500 miles is ok.

ugh, I know!

I drive pretty hard, I mean really hard, and only have to add 1 quart every 4-5K miles