JenB

I've been a lurker for a while (learned a lot - thanks!), but wanted to post now to see if others have had a similar issue and seek out advice/experience. And also to give a watch-out to others as well.

I have a 2010 GL350 Bluetec. Bought it in August 2010 new, and it has about 12K miles now. Had an early issue with the suspension/bearings, but that was resolved by the dealer. The car has been terrific since then.

About 2 weeks ago the CEL went on and car went to limp mode. The nearest dealer showed an utter lack of interest in figuring out the problem, so I went to another dealer who has been great so far (where I bought the car and who fixed the prior issue - but farther away).

They have now determined that there is corrosion in the fuel system, including in the fuel tank. They are still trying to figure out all the areas of damage, so I don't even know the full scope of the problem yet. The dealer says they have been in contact with MB USA, and have been advised that this issue comes from water in the fuel, leading to the corrosion. This is also a problem that MB USA says they will not cover under warranty.

I only buy diesel from mostly name brand stations (e.g., Shell). I don't go to any one station since I'm driving around and will fill up as needed wherever I am. But I'm also not going to some backyard refiner to get the cheapest price. Fuel tank cap was never left off in rainstorm/car wash/etc. - no single events of misconduct that could possibly introduce water into the tank.

So I now have a practically new Mercedes with what are shaping up to be some very expensive repairs resulting from just doing the thing you have to do to keep a car running, namely putting diesel fuel in the tank. As I said to the customer service rep at MB USA, if I can't go to a gas station and fuel up my car without worrying about incurring thousands of dollars of damage from that fuel, then the car is really not a viable automobile.

Has anyone else had this problem? I am trying to figure out if this is a one-in-a-million bad luck situation, or one that is more common and thus suggests poor construction/design of the fuel system. Has MB USA also denied coverage under warranty in other cases?

And for those of you with a Bluetec diesel - beware! It would be useful to hear from folks if there is anything that can be done to mitigate and minimize the likelihood of it happening to others.

This is such a disappointment and frustration, as I've been really enjoying my diesel. And I really would have expected more from Mercedes USA....

Thanks in advance for any advice and suggestions! And I'll continue to post as this situation evolves.

ddcha

Sorry to hear about your problem. I wonder if the blend of biodiesel may be causing the issue.

JenB

In a strange way I might feel better if it was biodiesel, but I haven't been using it. Just straight up petroleum diesel bought from retail gas stations.

Makes me concerned about prospects in the future too....

blee911

I have a 2011 GL 350 purchased in late August. I have close to 13,000 miles (lots trips from the Bay Area to San Francisco, LA, Reno, and Tahoe). About one month ago the CEL came on. The car didn't go into limp mode. The dealer took a little more than 2 days to remove the CEL. They claim that the Add Blue level was low or there was some issue with the pump lines. The work order doesn't specifically state anything about the pump lines... this was something I remember the service manager saying. The fault codes were 20E823 and 20E821. This problem came up a few weeks after I had my 10K service done which included filling up the Add Blue tank. It's now been a little over 1 month since then and no problems so far.

I'm concered about your non-warranty comments. Please keep us posted! Where in California are you? I'm in the South Bay (Saratoga).

aeggroup

Can I ask stupid question ? .... What is CEL ?

LEOSOPHIE

Check engine light.

blee911

Never a stupid question when it comes to acronyms in today's crazy world. :-)

Check Engine Light.

LEOSOPHIE

My friend fueled his Duramax which has a water separator in Gorman
Ca. Within ten miles the truck died and was towed back to the station where they had to drain the tank of the water and change the filters. He had some further issues that Chevrolet would not warranty.

Fourdiesel

1) Corrosion to the fuel tank is nearly impossible since the tank is plastic! It IS possible to get a large charge of 'crud' from a suppliers underground tank especially if he just got a large load of diesel delivered immediately before you refilled. Even the most reputable fuel stations don't religiously change the filters on their pump lines.
2) That being the most likely cause - your vehicle isn't old enough to get much corrosion of its own - carefully think back on where was the LAST place you fueled up before you got the CEL and the 'limp home'. Talk to the station personnel and see if you can find out if anyone else complained about dirty fuel from them about the same time as you. If you can, find out when they got a diesel delivery before you purchased your fill up. If you can show that you were not the only one, you MAY have a claim against their insurance.
3) Hope that dirty fuel is the cause because if it really IS corrosion there is a good chance all the high pressure pump parts, injectors, etc might need to be replaced $$$! Also, if it is corrosion, something other than fuel caused it. If it happened very fast, water is not enough.
Good Luck

JenB

Thanks for replies!

I talked with the service advisor at the dealer this afternoon. He said that they have finished the diagnostic and all of the parts that have come in contact with fuel are corroded. They are not done with the estimate but it was at $4,800 so far!

Fourdiesel- really appreciate your thoughts. I do know where I fueled up right before this happened (and can verify with credit card receipt). Also, if corrosion is caused by something other than water, any insight into what that might be?

Don't know if it means anything, but I was on half a tank when CEL/loss of power started.

The reality is I have way more questions than answers!
How is the tank corroded too if it is plastic (per Fourdiesel)?
How long has this been building - was it quick or has it been accumulating over time (but not that much time since I've only had the car since August)?
Can this happen from just one tank of bad fuel?
Is there not a water filter? (I read that the E bluetec has a water filter, which means that Mercedes has some concern about water in the fuel supply. Is there also one in the GL?)

Not only am I concerned for this immediate repair expense, but what the implications are long term and the potential for it to happen again....

I'm also going to check around NHTSA to see if there is any pertinent info.

Blee911 - I'm in SF. And yes, the quick rejection of the warranty is a big concern! Warranty states that anything caused by "poor fuel quality" is not covered. So boom, they just say "bad diesel" and MB USA takes no responsibility. Who knows if that's really even the cause, or just a convenient out. They definitely have nothing to gain by actually digging to the root cause. So now here I am myself trying to dig into the cause....

alx

.. you have water in your fuel. a lot of it. it could be due to two things. your driving and storage habits; ie you keep little fuelin tank and outside temps vary widely when parked for over 24 hours... or two you are buying bad fuel.

one can be argued is a design problem. which the gls do not have as theyhave water separators and i have yet to see one collect any meaningful amout of water

my bet is you are filling up with bad fuel. brand name of fuel is largely irrelevant. fix the truck, buy a case of stanadyne additive and mix accordingly. this will take care of the water in fuel you seem to be putting in...

my 2 cents

aeggroup

If to assume OP got the diesel from one or several Branded stations like Shell or Hess....you suggesting to spend $5K just for doing the right thing - go get fuel from Gas Station.
I think there is something wrong in your advice..or your 2 cents cost much more.

alx

my 2 cents are factual and prolly mimic the dealer/ mbusa stance too. if dealers diag is correct then there are two ways water is presented. one is a design issue that is not presented in the gl. the other is a user problem. if you dont believe me fill up your diesel with gasoline and try to warranty the damage. in the ideal world the owner can take samples of the fuel and have it tested forwater content and then offload blame to gas station. this most likely will not work. the only real solution is fixing the truck and taking care of the fuel quality... which if you dont know which of the offending parties is providingis fixed by adding additives.

really. that simple. is it what the op wants to hear? certainly not. but... dont kill the messenger...

LEOSOPHIE

Branded stations don't necessarily sell branded diesel. My brothers have a Conoco 76 truck stop that sells branded gas but the cheapest available diesel. Arco even calls their diesel in Ca Caminol and not Arco diesel.

mdadgar

Branded stations don't even sell branded gasoline. The trucks are all filled from the same terminal and then brand-specific additive packages are added to "differentiate" them.

- Mark

alx

almost true. brand tankers fill up from the top half to 2/3 of the storage tank. the bottom is left for the nobranders. branders also as you said have their proprietary additives added at a later time.

lkchris

Water in fuel is a problem for all diesels, not just Mercedes.

The fuel filter at your engine is supposed to separate out water, but I suppose can be overwhelmed by a massive quantity.

mdadgar

Ahh, interesting. Thanks for pointing that out.

- Mark

NevadaNick

Dont these cars have a water in fuel indicator ? Every diesel pickup i've owned does and when X amount of water is detected it tells you at which time you need to shut it down and investigate before ruining parts.

Fourdiesel

If it is possible - and by now it might be difficult - try to get the dealer who has the car to get a sample of the corrosion products from the bottom of the tank (which will need to be thoroughly cleaned and flushed anyway). You should take that sample to a reliable lab for analysis to find out how much water is there, if any acids or bases are also present, the 'stuff' that is in the corrosion products etc. That will provide the clues you need to find out where the bad stuff (whatever it is) came from.
If it were me, and I was paying the bill, I would REQUIRE the M-B dealer to provide you with ALL the parts that are replaced. No part, no money! Best to do that BEFORE they start work but it is never too late to try. Those parts that are corroded on the inside will also provide clues as to the source of the problem.
For technical help with the analysis and reports, find a professional engineer that specializes in metallurgy and corrosion. Consult with that engineer. He will also know which labs in the Bay Area are good for your purposes. It may be worth while to pay for his professional advice since it looks like your repair bill will be substantial. If he can help you show how and where the problem started you are a long way to being able to lay off at least part of the cost. Use a PE because his credentials will stand up in court, if necessary. [And I sincerely hope it isn't necessary!]

JenB

Some thoughts on your comments (again, much appreciated - and no, alx, I won't kill the messenger .:

I am assuming that the cause of the corrosion in the system is water in the fuel (fourdiesel - I have asked if the dealer has an idea if this was sudden or built over time, but I have not heard back. Since I don't have an alternate source of corrosion at this time, I'm assuming the dealer is correct in determining it's water).

I usually try to refuel with about a 1/4 tank left, although a couple of times the low-fuel reminder has gone on. But I refueled asap after that notification. I live in San Francisco where the temperature is about as stable as anywhere. So driving and storage habits are not unusual.

I mentioned that I mostly buy my fuel from name brand stations only to make the observation that I'm not going to any really out-of-the-way, off-the-grid sources for diesel. There is not one station I always go to, but all are primarily in SF or along major highways in Calif. - basically sources that any diesel driver would be expected to use.

My driving and refueling behavior is entirely in the range of normal, responsible and expected for any car owner.

As many of you have said, I may have gone to a fuel station with too much water in their diesel. But based on what I've learned (from you all and other research), it is not uncommon for there to be some water in diesel fuel. So then what about filters to remove excess water? Are they on the GL? If they are, do they not have a sensor when they are full? BTW, these are questions I have asked of the dealer and I'm awaiting their reply....

And if the situation is easily prevented by using an additive like stanadyne, why doesn't Mercedes just recommend using it on a regular basis?

I certainly understand that I ran into some bad luck here. But I also am just stunned that I can go from doing a normal and necessary thing like filling the tank at the gas station to $5K+ of out-of-pocket damage without any warning light/sensor/beep/whatever!

Needless to say the answer will greatly affect how I feel about this car going forward!!

And though I keep repeating it, I really do appreciate all the comments. I do like the dealer I'm at, but they don't give any meaningful detail beyond $$ unless I ask the questions (and even then, I'm still waiting for answers). So the more education and information I get the better. And of course I'll post any resolution as it comes.

JenB

(Whoops, looks like I posted before reading your message Fourdiesel...!)

Yes, I have asked if there is fuel left in the tank and that I would like access to it if they still have it. And I've asked the question about how much water could have caused this.

Fortunately California law requires that you be allowed to keep all of your parts, and I've requested those too. Since no replacement work has been authorized yet, old parts had better still be around!

I've also started talking to my insurance company to see if they can bring any of their expertise to sort this out.

This situation definitely warrants lots of questions and answers....

alx

Your fuel filter has a water separator functionality. I have yet to see a gl that would retain water in its fuel filter though. Ask them if they found any water in the fuel filter.

JenB

OK, wow, just got the estimate from the dealer. It is $15K!!

No wonder the guy from MBUSA didn't return my call today.

Got to let my brain process this for awhile....

dgiturbo

OK, lets tap the brakes here for a second.
$15000 to rebuild a (mostly) plastic fuel system that supposedly was "corroded" with water????
Water comes in plastic bottles nowadays!! Also the fuel filter in the center of the engine has a water sensor which should have given you a dash warning light.
Anyways, I went to this web site and found the following prices. The tank is plastic, and cost around 1200. The water sensor is about 100, the fuel injectors run about 2400 for 6 of them, the in tank pump 400, fuel rails 1500, main diesel pump 1200. I may have missed a few things, but so far let's overestimate and say max $7-8000 in parts? At $15000 that leaves a lot of ca$h left over for labor!! And that's for a complete system.

My point is that I have some experience with working with fuel systems, and I find it hard to understand that if you filled up a working vehicle with 1/4 tank prior, how could there be so much water related damage with a system built mostly of plastic parts? (Tank & lines). After the filter, the fuel goes to a VERY high pressure pump and metal lines, then is injected into the engine. I would love to see how water in such a short time, pressurized to over 26000PSI could corrode a metal line designed to carry petroleum based liquids.
Fuel systems are designed to pump and deliver liquids. True your engine won't run on anything but diesel, but your fuel delivery system will deliver whatever non viscous liquid you run through it. Over time, other damage will result, but you had just filled up, and are still on the same tank full. Corrosion by water takes several months, usually with a vehicle sitting. My 91 Mustang fuel tank rusted after I had the vehicle sit with an empty tank for 3 years!!

Also, if the corrosion by water is the issue, the result is RUST. These rust particles will be trapped by the filter, causing it to clog and starve the engine of fuel. So they should show you your severely clogged and rusty filter as a starting point.
Then have them explain how plastic can rust, as all the lines before the filter are plastic, and the hoses are rubber.