Mercedes-Benz Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1
I wanted to change the engine oil on my 12, GL350 and when I removed the engine cover I found a lot of oil on the front of the engine. The bottom half of the engine is covered with oil. Also the serpentine belt is worn out and there is rubber all over the place from the belt. I purchased the vehicle not too long a go and I know the engine did not look like this when I got it. Currently there are no codes that would indicate there is a problem, the oil is low but there is no indication that the engine ran without oil. I was slightly on an incline when I checked it. I will check it tomorrow in level surface. I have attached a few pictures. Please let me know if this is a common problem with the engine or am I the lucky one. I can do the work my self I just need to know what am I getting my self into.

Thanks.
20190902_215817.jpg
20190902_215907.jpg
20190902_215840.jpg
20190902_215939.jpg
 

·
Registered
Joined
·
592 Posts
Looks like a simple oil leak, just have to find it and replace the gasket/seal, maybe valve cover? Or somewhere at the front of engine? Definitely a new belt ...Good luck.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #3
Hi Tony,

Thank you for your reply.

I looked at the engine diagram and the oil cooler is located on the top of the engine about half way on the engine. It seems to me that the problem is lower on the front of the engine. How likely is it that the oil filter gasket that goes between the housing and the block would cause the leak?
Last night I started cleaning the front of the engine and worked on it about 1.5h... made some progress. I used engine degreaser. It was removing it slowly. This morning I went and purchased some WD40 along, some oil and some dye.
I also checked the oil and there was none showing on the dip stick (has me concerned). If the oil level was too low should the oil level sensor detect the low oil level and send a warning? I looked online to see if I can find some information about the oil level needed to activate the oil message but could not find anything. If there is any info available I would appreciate it.
 

·
Registered
Joined
·
592 Posts
Best way to find the leak is to get it clean, then full of oil obviously, then run it, and wherever oil is coming from, that would be the leak. What a mess. Every Mercedes I've ever owned, about 20 of them, have all had a light that comes on if you get about 80% of a quart low. This is a feature I really like because you can't let it get so low that the engine burns up, as long as that light works... I have not been low on oil in my GL so I don't know if it does the same thing. But it would be a first if it doesn't have a little picture of an oil can that lights up when you get a quart low! Maybe another GL owner will add info here about this. ! With a leak as bad as what you've got it should be clear where it is coming from, once you get it cleaned up good and shouldn't take much running for it to become evident. I looked at my owners manual and it says nothing about the Low oil level warning light...
 

·
Registered
Joined
·
30 Posts
Discussion Starter #5 (Edited)
Hi Tonylinc,

Your input is greatley appreciated.

Over the past week I have been scrubbing the front of the engine so I can see what is what. You are correct what a mess.
I used a small paint brush with a lot of engine degreaser and managed to clean the front of the engine. I also changed the oil. I was concerned about the quantity of oil left in the engine. It turns out that I had about 5 quarts left in the engine. This is good. Looking at the manual on page 246, it talks about the low oil level warning. I still cannot figure out where the oil comes from. I added the dye as you suggested.

Yesterday I took the drive belt off and the top idler pulley was rough looking. It had grooves in it from the belt. This brings me to another questions. As I was taking the belt off, I noticed that it goes over the pulley, but the pully is smooth. Shouldn't the pulley it be groove? Looking at the belt diagram, the belt goes over the pulley and it seems that the pulley should have groves in it to coincide with the belt. How is yours? I will call the dealer and see what they say.

After I cleaned the front of the engine, I took it for a ride. I will let my wife drive it to work for a few days and see what happens.
 

·
Registered
Joined
·
592 Posts
Some of those idler pulleys don't have grooves. Just make sure they turn freely and don't feel like there's gravel in their bearings. Often those are cheap to replace, I got new idler pulleys for around $30 or less for my ML320. If you have it all back together and it is running fine, I wouldn't worry. The pulley witrhout the grooves, probably just turns by friction, or is just there to hold the belt in its place. I have not looked at my belt yet, with 144K miles it is hopefully not the original belt!! Think I'll go have a look at it now.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #7
Spoke with the dealer rep. and the idler pully should be grooved. Purchased it for about $50 and installed it. I also replaced the O ring that is in the inlet pipe. I have 2 more O rings coming and we shall see what happens after.

Thanks
 

·
Registered
Joined
·
592 Posts
Did a little more research and found the housing the the oil filter goes onto, has seals that can begin to leak after a while. Replacement seals are only around $15. A telltale sign that your oil cooler seals are leaking is if your belt tensioner is dirty, the oil gets on there and dirt sticks to it. Also there is a grooved idler pulley and a smooth idler pulley. The site has a video of a guy replacing the oil cooler seals. This is for the M273 (V8) and M272 (V6).
 

·
Registered
Joined
·
592 Posts
Regarding the idler pulleys one is grooved and one is smooth. RockAuto has both and has part numbers for those, and cost about 23 dollars each. I found a Gates belt tensioner on amazon for only 56 bucks so now I've ordered all those, and read too that if you have a M273 engine and don't know how old your thermostat is, you should buy a new one as well. So I ordered one of those, around $80, they are not a normal thermostat that would usually cost around ten bucks, ..Wouldn't ya know. For the slightly leaking oil cooler lines Amazon has the Mahle kit of seals for those at a cost of about $13 and that FCPEURO page shows a diagram of the pulleys etc and also I found a video of a guy replacing the oil cooler seals making it look like a very simple job. Belts I found around $40 Once you renew most of these parts at the front of the engine, you're good for probably 60K miles before needing to think about them again, maybe even more. FCP EURO has kits for these cars like instead of just spark plugs, comes with ignition coils too, and kits for the belt/pulleys/belt tensioner, all in a kit. Pretty nice. I thoughy my GL was running perfectly but with 144K miles once I replaced the coils at about 30 bucks each, I am sure glad I did, it really runs well now. I'm going to have my indy replace all the belt stuff and thermostat when all those parts arrive. Happy motoring!
 

·
Registered
Joined
·
30 Posts
Discussion Starter #11
I still have not figured this out. Purchased the O rings. Installed them, along with the new serpentine belt and the grooved idler pulley. Last week my wife called me and she said that she heard a noise and the steering wheel got stiff. I told her to turn around and go home. Luckily she was not too far from home. When I looked at the car the serpentine belt was gone and was wrapped around all the pulleys. Friday went to the dealer, got a new belt and took off all the things in front of the engine that has an O ring. I also checked the turbo and the impeller has play. Does any one know where I can get a rebuilt kit for the turbo? I will upload the video shortly.

james.calton1 - you are correct. I do have the 642 engine.

thanks.
 

·
Registered
Joined
·
592 Posts
Sorry to hear it is still having issues. For the belt to be coming off like that I would think that one of the pulleys it drives on has got to be defective, maybe power steering pump or anything else the belt runs on. Maybe the alternator pulley? There's gotta be a culprit in there somewhere. I am not familiar with that engine but I doubt the turbo is belt driven? If it were my car I'd take it to a good indy who knows these cars. I know an indy who is freelance but I know a little more about Benzos than he does. I also have a foreign car shop locally but they aren't very cheap. Is the leaking oil issue all fixed up?
 

·
Registered
Joined
·
30 Posts
Discussion Starter #14
Thanks tonylinc.
I have inspected all they pulleys and do not see anything out of ordinary. The belt was brand new. It was two weeks old. I went to the MB dealer and they gave me another one under warranty. The turbo is not belt driven. No turbocharger is.

The oil leak is still not fixed. I ended up taking all the plumbing on the air inlet side all they way up to the turbo, which is located in the middle of the "V" all they way back. There, I found some oil pooling inside the turbo. Checked the radial play of the turbo and, in my opinion, had play. Thinking that the oil can be coming from the turbo, I took the turbo off and checked it. The radial play turned out to be around .01". I also I called Turbokits.com and spoke with a tech there, ( which by the way was very knowlageble and was not trying to sell me anything. He provide pricing and answered all my questions). He stated that Garrrett turbos have some play even when they are brand new . "The bigger the turbo the more radial play.". He also stated that turbos can have some radial play but not axial play. When oil is pumped through, they center them selves and the radial play disappears. Last night I reinstalled the turbo and this evening I will try to finish up the car and see how it goes.

Also I found that the air filters were really dirty. My guess the previous owner did not take replace them as required. Since the right quantiy of air was not being introduced into the engine, more air is being sucked from the crank case, thus, more oil was being sucked through the intake. Well, at least, that is my theory... for now.

Thanks.
 

·
Registered
Joined
·
592 Posts
When I got my GL I bought it from a used car dealership that describes themselves as having "fine cars highly serviced". Once the car was mine, I looked at the air filters. Filthy. At least 20K miles, maybe more. Cabin air filters, same, although that's typical. The sticker atop the windshield indicated a few thousand miles to go on the oil change. I changed it anyway and when I removed the oil filter, the oil filter said Made In Korea. Seriously, who is going to put a korean made oil filter in a Mercedes? Basically everything on the car that could be "serviced" was in need of service. I commented on how the tires looked new. Sales guy said "YES, we changed those because the tires that were on here had cracks in the rubber". Closer examination showed the tires were made in 12th week of 2016. I guarantee this dealership had not spent a penny on servicing this vehicle, at all. This small dealership had not so much as sprayed Windex on the glass, on this car. Hell, it was lucky to have air in the tires!!! I'm saying all this because you mentioned air filters. I also learned that putting the air box on top the engine on these GLs can result in improper air intake if you don't get the airbox on perfectly right, resulting in a Check Engine Light... and it is quite a hassle to get the airbox on right, at least on the V8, what a design!!! The eighth or tenth time, it is definitely on there correctly now! I do believe however that it was the ignition coils that were causing the Check Engine light to come on, because once I replaced those the car runs noticeably better. Just lucky for me that all the stuff I serviced is easy to do, somewhat fun, and fairly inexpensive as well. But I feel sorry for that dealer's other customers. Trust NO car dealer in the World!!! New, Used, it doesn't matter, if they are talking, then Lies are being splashed around the room. This jerk even said he had a Carfax, multiple times, never got it. He said YES we have service records. Those consisted on ONE Page receipt for some power steering fluid. If I hadn't had three (four?) martinis before buying this car I would have had the sense to know this guy was a liar. The guy came to realize that I knew more about these cars, and diagnosing/servicing/repairing Mercedes in general, than he does, and asked me to become his partner!! Is that going to happen? Absolutely not. No snakes in my future, thank you. It's just lucky for me that the car is in great shape and runs beautifully, having now been fully serviced..... by me. I found Mann air filters and oil filters are so easy to get on amazon, and they are good filters, I don't know why people neglect their air filters so much. MB2369. I hope your theory works out!!
 

·
Registered
Joined
·
30 Posts
Discussion Starter #16
Thanks for sharing your experience. I feel your pain. I purchased the vehicle several months back for my wife and the sales man stated the same thing. He said that the car was serviced at the dealer and pulled the car fax for me and it was all there. Liars. Never trust a salesman. He told me that the previous owner did $4000 of suspension work, did not know what type. In any event. I am sure i will figure the oil leak out. I just do not have that much time to devote to it. While I am at it, I think I will replace the transmission fluid just to be sure.

In mine the air filter boxes are not that difficult to remove and install. I have the OM642 engine which is the V6 diesel. Slightly different than yours.

I also shop on Amazon as well, I also go to the dealer. Over the years working on MB's I have developed a good relationship with the parts sales man and I get a discount on the parts.

How many miles do you have on yours? Oher than routine maintenance, did you have to fix anything?
Thanks,
 

·
Registered
Joined
·
592 Posts
Thanks MB2369! I haven't had to fix anything. It has 144K miles on it. looks runs and drives like it is new. Thank you. The way the air filter box fits atop the V8, it is hard to make sure the mouth fits perfectly over the oval shaped thing it's supposed to meet up with. And there is a wire spring at the back that's supposed to slip over the top and hold it down. The first seven or eight times I put it on, it was probably not on there 100% right. Practice makes perfect, now I know it is on there right! Kind of different from all the other Mercedes I've owned. I also drained and refilled the coolant about seven or eight times the other day... spent the whole day. That's a whole 'nother story. It isn't easy being OCD I guess!
 

·
Registered
Joined
·
28 Posts
I had a similar experience with the oil leak that looked like your. On mine, which is a GL320 Bluetec diesel, it turned out to be the o-ring for the little triangle looking plastic box in front right behind my oil dip stick. The o-ring is where this box attach to the metal engine part. It may (or may not be) the same on your.
 

Attachments

1 - 18 of 18 Posts
Top