Keymasterx

Our 2012 GL 350 with 25k on it gave us the check engine light. Took it in and 2 days later, get it back. Dealer says the ad blue heater element went bad. Replaced under warranty. He claims it was replaced with a heavier duty part. There was an issue with the originals. Apparently something about the ones running in the states being insufficient.
Sounded kinda fishy. No recall for a known faulty part??
I don't know. Just wondering if any one else has heard about this or had part replaced. Do I need to worry about it going out again?
Thanks

alx

Yes, there is an updated part for the heater.

It is a common problem with all heaters up to an including my2012. Issue is systemic across all diesel models as they employ the same potted "Ж" shaped heater element. The new element looks identical, but has a different Bosch part number so... Who knows ...

There is no recall as it is not a safety concern. Interestingly enough it is not covered by the 7/70 emissions warranty either. The part is expensive- depending on model it ranges between $650 and $1250 retail and includes the whole bucket with level sensor and piping / lid for the **** pump

Keymasterx

Thanks for reply
Thankfully they covered the repair under my CPO warranty. Service guy said not only is the part pricey, but they have to remove the entire ad blue tank to replace it which is highly labor intensive.
Only good thing is they refilled my ad blue for free as part of the repair !!☺️☺️
Keeping my fingers crossed as to the longevity of this system. I'm loving the range we are getting out of each tank and now that it's warming up, diesel and premium fuel costs are on par.


N

alx

actually, removing the tank is a 30 minute job... putting it back on is about an hour as you need to fiddle with the harness on the top.

Keymasterx

HA! I guess he just made it seem like more work to justify how long it took them to get work done.
Thanks for info.

merlyn412

we have a 2011 GL350. Out of warranty, and the heating element on the adblue tank needs replacing.

Dealer wants ~$2000 to replace.

I'm somewhat mechanically inclined. Has anybody replaced the heating element? Part #'s, or any advice would be greatly appreciated

mike278

Something you can try since there is no cost involved is to remove the adblue tank, drain it, refill completely with water. Let it sit overnight. This will remove the urea crystals that may be screwing things up. Drain the water completely and reinstall. fill it with a quality diesel exhaust fluid and clear the codes. May save you some money. Worst case you'll be out of about an hour or so of your time.

alx

dont bother. it is one of two things.

either his preheater resistance has drifted a bit and the scr module is tricked into thinking the preheater has gone bad or... his preheater is truly bad.

before tearing into the adblue preheater, i would bring the truck into the dealer and ask them to update the scr controller software version to address the drift problem described above. the book says 1 hour for this so... about $140 in the US. even if you preheater is bad, you want the new code in the scr controller anyway.

if that does not fix it - his preheater is reading open across the leads on the connector. very common. unfortunately.

on diy - you can certainly try it. the oem part will cost you $720 on ebay (check for "gl350 adblue preheater"), the dealer will charge $1200- $1600 for the part depending on how they want to approach it - many dealers will not replace the preheater, but instead will swap the whole thing- tank, preheater, pump as a complete unit...

the task of replacing the preheater (part # A1644710975) is not complex, but requires common sense.

you need to drop the adblue tank from the bottom (usually 4 long screws on the four corners of the tank). if the tank is full it might be too heavy to be maneuvered by a single person. you have been advised
take a pic of how wiring harness is secured/ attached so you do the same on re-assembly
disconnect all plugs/ connectors
take note/ photo on tightening ring position (there is a mark on it- if there isnt- make one) so you can screw it back later the same amount of turns. ditto on basket lid - note its orientation
unscrew the tightening ring (a rubber mallet and a screwdriver does wonders)
remove/ unscrew pump from basket cover. notice the little o-rings inside. you will be replacing them with the new ones from the new kit.
detach basket from tank by twisting it (dont remember clock or counterclock- wise) and pulling it out. it will be awkward as there is little leverage with your hands in there.
assembly is in reverse. dont forget the new o-rings
very important - before buttoning everything up make sure you fill up the basket with adblue. feel free to pour some fluid in the pump orifices too (you will see them). this will prime the pump. if you dont- it will never prime and overheat and promptly burn up in the next hundred miles.

KrustyKustom

Alx,

Really appreciate your input on the tank. I have a 2011 and no issues up to now on the tank or heater but does not sound like a killer if I have to drop the tank etc.

Now to find that little oil leak that showed up!

-Krusty

alx

no, it is not a killer repair. fairly straight forward, but requires attention to the little things in there. and priming the basket.

on the leak - if it is leaking engine oil from the back of the engine - it is leaking out of one of two places- either from the intake-to-turbo seals or from the oil cooler.

first inspect if the main turbo intake seal is installed correctly. it can easily be pinched/improperly installed and thus leaking. if it is installed correctly, but leaking i would replace it with a new seal (updated part) along with the little side seal (egr seal) - also updated.

if it still leaks - it is your oil cooler seal. how adventurous do you feel? it is prolly the dirtiest repair known to man on the om642 engine lol... fairly straight forward too, but you need to pay attention to the plastic flapper motor and assembly as they like to break when removed. other that that- it is just a dirty dirty job

KrustyKustom

I do not think I am up for the oil cooler seal repair if that is it! I am going to thouroughly degrease the bottom this evening and watch it for a day. It is leaving a dime size drop when parked over night at the back of the engine. 76k miles so I doubt rear main.

Good idea on the turbo intake seal. I will pull the plastic part off as well and check the red seal which I replaced at my 60k maintenance for good measure.

If its one thing I cant stand its an oil leak...

again, thanks for the experienced input.

krd2023

Our adblue heater died outside of warranty at around 60K miles on our 2010 ML350 Bluetec. After the expensive repair and while leaving the dealer lot, the Check Engine light comes back on to reveal (according to the dealer) the adblue pump died- another expensive repair. After other common issues as discussed in this and other threads, including oil cooler seal repair, the engine seized in April 2015 @ 82K miles and I'm getting zero assistance from MBUSA as detailed here: https://mbworld.org/forums/diesel-fo...ne-seized.html

alx

The pump died shortly after the heater replacement because the dealer did not prime. Their fault.

The engine seized because it uses oil (as all om642 Diesel engines) and you were not checking the oil level as needed. Instead you relied on the oil level Sensor which prolly sludged up and malfunctioned. That is how the om642 engine seizures play out. Oil level should be checked at least monthly via the dipstick.

Good luck

KrustyKustom

In regards to checking oil I actually check mine weekly. And if you drive a lot of short trips, and in cool weather especially I think shorter oil changes are well advised to prevent bio diesel sludge.

Let that diesel run for a minute at least on cool mornings to get that oil pumping.....

samiran

Weekly sounds good.

I'll point out that I think the manual indicates check oil every time you fill up.

I'll also point out that "normal" oil consumption for these is up to 1 liter per 1000 miles, which means that you could be half that, and still have to add 2-4 liters between oil changes.

That's a LOT of oil, particularly because most people don't even check the level between oil changes (arguably most other cars don't need you to.)

But these OM642, it's stupid not to check the oil at least once a week and everything you fill up the tank, you're really playing with fire if you don't.

krd2023

For those interested here, please be aware of systemic issues with certain ML years with the OM642 engine. Mine is a 2010 ML350 Bluetec with engine failure at 82K miles. I've been keeping my dilemma current here https://mbworld.org/forums/diesel-fo...ne-seized.html , with my most recent update on my thread as follows : Since I started this thread in May of this year, I remain perplexed at MBUSA’s virtual silence as it relates to my attempts to resolve a premature engine failure on my 2010 ML350 Bluetec with OM642 engine (which, as you can see from several reliable online sources, is an engine prone to problems). I’ve gone so far as to offer to buy another MB from the same dealer if MBUSA helps negotiate a fair trade-in value, yet MBUSA won’t engage. Here is my status update including some revelations as of today, now almost 5 months since the engine seized and my ML350 Bluetec continues to sit immobilized on the local MB dealer lot:

- The MB-recommended oil, Mobil 1 ESP from the dealer, was used throughout the life of the car and changed at 10K mile-recommended intervals and when the dealer recommended an oil change at services (where dealer services were done at least twice per year since I bought the car new). The oil level on dipstick was within safe operating ranges at all times (before and after the engine seized, and oil level was checked by me at frequent intervals). If oil changes on this car should be done more frequently, then MB shouldn’t recommend this 10K mile interval in the owner’s manual and maintenance booklets. Since 2010, I see that Mobil 1 ESP is no longer the recommended oil (and sources show it’s prone to sludging), the MBUSA Western Regional After Sales Manager I was dealing with no longer works for the company, and the service technician in charge of my car services at my local dealer no longer works there, the dealer can't locate an OM642 for engine replacement because of necessary engine modifications since 2010 and stated that I'll need to go with a different engine model, all for mysterious reasons to me.
- I’ve realized from recent research that I paid partially or fully for premature repairs since 2010 which should have been fully-covered by MBUSA and/or the dealer, including repairs involving glow plugs, adblue heater and pump, oil coolant seal leaks, a lunge or surge while driving sometimes from 1st gear to 2nd but never diagnosed, the engine “stuttered” when first accelerating at random times, battery replaced twice (indicating faulty electrical system but never diagnosed), and more, all of which is documented on dealer letterhead and accessible in MBUSA systems.
- As indicated prior in this thread, the only recent response I’ve received from MBUSA was a standard letter indicating they deem my car is not a lemon and will therefore not provide me with any assistance.