Lioninstreet

It seems from trolling MBW that the Mercedes diesel, particularly the post 2011 in the ML, is fraught with issue specifically related to oil sludging causing turbo and engine failure..

Im in the market for a 11-12 facelift Rclass with the newer design motor (possibly considering 09-10 as well) and was wondering if anyone could comment on their higher mileage experiences with their MB diesel.

Thanks in advance.

efzauner

I had a 2008 CDI and got rid of it at 200Kkm for a very low mileage 2011 350 Gas. My colleague had a 2010 and also traded it in for an Infinity.
I will not get another diesel. Period.
Both of us had oil cooler leaks. Mine under extended warranty. His cost $7K to fix
I had a $3k particulate filter replacement and an injector relay also replaced under warranty. Injectors go faulty at almost $1k a pop. After the VW emission fiasco I read up on Bluetech and it is very complicated.

On top of that mine got very noisy over 120K km and the dealer said it was normal. Yes as diesel injectors wear the combustion is less than ideal at low loads as in driving around town. I just winced every time at the rattle and clang. It really detracted from the overall driving experience.

So. go for a Gas... what you pay extra on gas you will save on long term maintenance and repairs.

marc hanna

Mine has been quite reliable. All the cooler leak issues of the past have been resolved, but I can definitely understand how those who got stuck with the repair bill might have a bad taste in their mouth. I generally don't think MB services the diesels properly in North America. 9 times out of 10 they replace an injector when only a seal replacement is necessary. That's a 10 cent part versus a $800 part. Poor quality fuel in North America also causes premature injector and high pressure pump wear. This can be resolved through fuel additive to bring it up to Euro standards.

I've had a few diesels and in general, I prefer them over gassers.

thetonka

The bad service was a huge part of the problem Ford had with the 6L Powerstroke. In international trucks the engine was really good, but due to some changes Ford made and TERRIBLE training most 6Ls ended up appearing far less reliable then they were.

The Bluetec is a really complicated engine, but if you dig into it it is a well engineered and well laid out engine. We are stuck with a couple of parts that have high infant mortality(cooler leak), some bad emissions stuff(not really MBs fault since much of it is mandated), and a lack of really good Diesel Mechanics. The one shop I was going to has lost my business due to some incompetence and the tech arguing with me that my '09 needs a waste gate. If you can not understand that the VGT turbos do not have or need waste gates, why would I trust you to work on my car?

The 6L Ford guys have a large number of aftermarket companies that have parts to fix pretty much all the problems with the 6L. Now, you can by a 6L Truck, Excursion, or Van and put on or replace enough parts that the engine will put out a HUGE amount of reliable power.

We do not seem to have the same drive for aftermarket parts and repairs as the Light Duty truck market. I will be looking into upgrades next year myself. While I am not looking for massive power adders like I did with previous Light Duty Diesel Truck, I will be looking at upgrades to faulty, or failing parts. Perhaps a tune. Whether you are will to go to these lengths or not is a big factor in buying a MB diesel out of warranty.

Lioninstreet

From what Ive been reading here on MBW a lot of the major failure issues are caused by sludging. Am I wrong?


In shopping for a used BlueTec (particularly from a indy dealer where they are mostly found) how in the world would you know if the prior owners were religious about oil changes with the proper oil?


It almost seems safer to hold a revolver to your head...

marc hanna

There are far from a lot of sludging issues. Out of the millions of these engines that have been produced, there have been about half a dozen sludge issues reported, and they all appear to have been related to improper oil/oil change interval.

Sludging tends to be a rapidly occurring event, so if you're looking at buying a used BlueTec, as long as your change the oil immediately, any risk of sludging is also immediately resolved.

I don't know the exact numbers, but there have been over a million of these engines produced per year since 2005. That's well over 11,000,000 engines (probably almost double that). If 6 sludge incidents occurred, that's a 0.0000005% sludge failure rate. For all intents and purposes, a non-issue.

Lioninstreet

Granted, once I'm an owner I can resolve any continued issue relating to sludging. So my concern is more related to any damage caused during the prior ownership that I'm inheriting. Immediately changing a maintenance protocol wont restore any potentially existing damage.

That issue aside, thanks for the input marc. I've noticed your posts over the few years I've been on MBW and you're pretty well versed in dealing with diesels. Me not so much, only gassers.

Maybe I should post this in the diesel thread but lets say I do get a diesel, what types of repairs should I expect during 50-75k of ownership?

marc hanna

Most repairs are tinkering type repairs. A hundred dollars here two hundred dollars there; but if you go to the dealer, it's a thousand dollars here a thousand dollars there.

Repairs I have done over the last 40,000kms:
Glowplug controller: $150
Wheel speed sensor: $35
Turbo actuator: $0
Rear right brake calliper: $180
Brake line fitting: $150
Injector seal: $5
Transmission fluid replace: $350
Everything else is routine maintenance

thetonka

I'm curious what your $0 actuator repair was. Do you have a thread on here about it, or can you post some details?

marc hanna

I did post somewhere. I re-soldered an electrical connection in the turbo actuator - it's a common fault on these Hella turbo actuators used in many makes and models - NA, Europe, and Asian. No problems since.

The alternative was an entire replace turbo which = $$$$$$$

thetonka

Thanks. Makes sense.

I suspect I have a leak but I have yet to find time to troubleshoot. Under constant load it will drop pressure, throw an under boost code, and go into LHM. I've checked the vanes and they look ok and move freely.

After my next business trip I'll be taking it apart and looking. Any tips and tricks I can find I collect so I can do this once and not drag it out.

thetonka

Marc, looks like you posted info in this thread
https://mbworld.org/forums/gl-class-...-cuts-out.html

marc hanna

Yes. That's the one.

Take off the cross-brace and engine cover. Then blip the throttle to see if the actuator arm is moving. If it moves, and your turbo vanes and bearings are intact, then the issue is not with your turbo. If the arm doesn't move, then disconnect the linkage at the actuator arm, see of the linkage moves freely, if it does, then the issue is likely with the actuator, if it doesn't, then the issue is with the adjustable turbo vanes and your turbo will need to be rebuild or replaced. In the case where the actuator arm does not move after disconnected from the linkage AND when you blip the throttle, then your actuator is faulty. From there you can either try to repair it yourself or buy a rebuilt one.

thetonka

Thanks Marc, these are all things I have either done, or plan to do.
I am not new to diesels, cars, or even electronics. Having spent some time under the hood I have to say that even with the complexity of these engines they are well engineered. Everything has a place, a bracket, a tab, or a mount.

Lioninstreet

I actually read your thread on the actuator repair a month or so ago Marc, pretty recourseful If I do say so myself. So your saying that in 25000 miles you only had the following diesel related maintenance?

Glowplug controller: $150
Turbo actuator: $0
Injector seal: $5

Granted it sound like you know what you were looking for but that's still pretty impressive. What was the mileage when you started with your R?


Have to admit I'm still pretty gun shy considering the additional wear sludging causes an engine and turbo prior to my ownership.

marc hanna

I bought it with 80,000kms (50,000miles) and now it has 124,000kms).

I've done other routine type maintenance like brake pads and rotors, oil filter, fuel filter air filters, etc etc.

It does have a very slow leak in the steering rack now, but I'm going to see if that will clear up with a little No-Leak (not the Lucus stop-leak).

thetonka

I've got a leak in my steering rack to, with 125,000 on the odo. Interesting.

Lioninstreet

My indy seems to feel that the steering rack leak becomes common across the GL, ML, R platforms with 80k+ miles.