Hi everyone,

Can't seem to figure out why my 06' C55 has started to rapidly burn oil. I'm receiving a message on the dash that reads something like "add 1.0l of oil at next service station."

The first time I saw this message was about 6 months ago and my car had only been about 5k kilometers since it's last oil change (i typically change every ~10k KMs or less). I added oil (0/40 European formula) only to have this message come up 3 more times over the course of the next 1,500-2k km's. Each time I immediately added more oil. After the 4th time I took it in for a full oil change, I've since driven about 1k km's and just got the message again today.

My car has 119k km's on it. I always get my oil changes done at a very reputable shop in town, McNally Auto. Is this something common? Has anyone else experienced this? It seems as though I need to add about a litre of oil every 1k km's or less.

Thanks!
F

 

I think it's normal to burn a little oil however, when I started needing to add oil, it was my rear main seal. Put it on a lift, get a light, and find the leak.

 

You, either, have a leak or burning oil, going through oil that fast is not normal. Mine has 95,000 miles and never had to add oil between two oil changes.

 

mine burns oil, its normal to burn some.
but having it needing a top up that often is not right.


I had a leak from my rocker cover gaskets, it was just a small seep, but when I had the gaskets replaced the oil use dropped significantly.


I've heard of rear main seal leaks, I'd be checking for leaks if I were you

 

I've always had to add a 1.0l in between oil changes. The car does burn oil. I've never seen a leak and have had it into both Mercedes and local specialist several times with no mention of it to include having my motor/trans mount replace 2 weeks ago with no mention so I'm sure you are just fine. But can't hurt to take a peek.

 

Have you checked you valve cover gaskets lately?

 

I seriously doubt a litre has come out of the covers.

 

Mercedes says 1 litre per 1000 miles is ok on the m113

 

I never trust the computer. If it is low at all it will say to add one?

 

the M113 does use a bit of oil normally, probably depends on your driving.


but a slight seep in the gaskets can accelerate the oil use, or main seal as well.


I daily drive my car, and before I did gaskets it would take 1L every 2-3 weeks. now after the gaskets have been done its more like every 6 weeks it needs 1L of oil.


they have a big sump too, so 1L out of a 8L sump isn't too much, I had a car with a 4.5L sump and losing 1L spelt fair trouble as any more than that would cause the pickup to run dry with high G-forces.

 

When I took my car on my holiday trip, I needed to fill twice only which was almost a 1000km journey. Was about 900 odd. The thing is I wasn't cruising with the car, so I assume obviously if you at WOT all the time it would consume more than normal. Now ever since I got back and seldom open her up, I haven't had to fill the oil for long now.
As people mentioned, from what I read in the Mobil1 booklet the car comes with, these engines in the 24hour Lemans if I recall correctly would consume oil after every some odd hours of racing. So you not exactly in the same situation but you are exerting the engine to its peak when you driving it hard. If you think its something worthy of concern as mentioned, check for oil leaks or do a leak down test and see if you have a low compression cylinder of the 8.
By the way I don't use Mobil1 but a quality alternative oil being Shell Ultra Helix 5W40 oil.

 

Also check under the oil cooler ( the aluminum ribbed rectangle, on top of the front of the engine attached to the left of the oil filter housing). On the C55 and mine in particular, the two O rings in the oil cooler hardened and oil seeped out the side and bottom of the oil cooler. Pretty easy fix, search around here and there is a youtube video on how to do the job in about 30 minutes. Dealer quotes $700 to replace two $15 o rings.

 

Here are the common causes:
-Mercedes issued a bulletin regarding the Valve/breather covers. If the breather covers are dirty/ clogged oil consumption will increase significantly. This is due to the high pressure in the crankcase which re-forces oil to the combustion chamber if the breather covers are clogged.
- Valve cover gasket.
- Rear main seal/
- Front oil port in the timing case.

Good luck.

 

Thanks everyone for the comments. I ended up taking the car to my shop (http://www.mcnallyauto.com/ - site is mysteriously down all of a sudden) to get it looked at. Been going to this shop for 4 years now. Head mechanic/shop owner (Charlie) put it on a lift and said it looks like a rear engine oil leak and would take 3-4 hours just to diagnose. Said it's a big job and the entire engine would need to be lifted out. I took his word for it and brought my car back a week later before I left town on a business trip. I dropped car off at the shop Monday morning (the 18th) and took off to the airport.

Went in this morning and picked the car up. See attached invoice for details on the job and what I was charged.

I have a tracking device on my car through my insurance company (auto merit program). The car was driven:

29 KMs on Tuesday (19th)
64KMs on Wednesday (20th)
44 KMs on Thursday (21st)

I got the car back it was dirty and covered in salt (i carwashed it the day i took it in). I gave it to them with over half a tank and got it back with less than half a tank. Mechanic mentioned to me they drove it a little to test it. I don't have GPS details, but most of the driving occurred between 6:30AM - 9AM and in the evening after 5:30PM.

Is it normal for a mechanic to put nearly 140km's on your car for a job like this?

I mentioned to the mechanic that I'd like to sell the car. I figure anyone who is interested in the car will likely want to talk to my mechanic as to get the history on the car.

The invoice mentions the engine was shampooed, it clearly wasn't.

The MB emblem on the engine of the car is missing.

I've contacted my insurance company whom is going to try to get me more detailed records on the information they might have on the driving that happened in my absence. As of now I can only see the following information.

-total distance the car was driven each day (stated above)
-any hard braking or hard acceleration events that occurred during those days

Tuesday, January 19 5:17 P.M.Medium Deceleration of 17 Km/h in 2 sec
!
Wednesday, January 20 5:28 P.M.Low Deceleration of 12 Km/h in 1 sec
!
Thursday, January 21 6:38 A.M.Low Deceleration of 12 Km/h in 1 sec
!
Thursday, January 2 19:51 A.M.Low Deceleration of 12 Km/h in 1 sec

I am hoping to get GPS information on where the car went and how many trips were done and the distance of each trip.

What should I do? What would you do?

I've spent over $5k at this shop getting repairs and maintenance done on my car over the last 4 years. They know me well. I will depend on them when it comes time to sell my car as any buyer will likely want to talk to my mechanic.

I have 1 interested buyer who is a customer at the shop. He wants to meet me at the shop on the first Saturday of February to get Charlie's opinion on the car.

Feedback appreciated

 

I dont know if there is much you can do. I would be pretty upset though. Have you talked to the shop owner at all?

 

I've taken my C32 to McNally Auto as well (at the recommendation of others from the forum), though it wasn't Charlie I dealt with, but the service manager instead. They seemed to be very honest and up front people; if you ask them about it, I'm sure they'll be able to give you a reasonable explanation for where they took the car and why. If you're not happy with their choice to do so without informing you, I would suggest you voice your opinion to them and see what they can do to rectify this problem.

Based on the info you provided though, it seems to me as if one of their mechs took your C55 to go home and get back to work for multiple days?

 

Another possibility is that someone was joy riding in the car.

I know some shops will move the cars around at the beginning of the day and at the end of the day from inside the shop and parking lot areas. Based on the timing it looks like whoever was moving your car took it around the block several times for a joy ride.

A shop I have gone to had a guy who would smoke (saw this first hand while he was in my car) while moving all the cars around. Needless to say that was the last time I went there due to that and many other reasons.

Either possibility is most definitely worth complaining about as both are very unethical business practices.

Don't say you have the GPS data first, tell them you noticed that the km's were much higher than expected when you got the car back. See what they say first and if it matches the GPS data.