Thimee

Been loving mine, so much that I bought it at lease end - it's a pity that the only way to get a proper engine in a ML/GLE seems to be limited to 63's. So my plan it to just keep mine forever and forever with an extended warranty.

Sadly however everything mechanical will eventually break. Driving home from the grocery store, I had an odd feeling of no power. I wasn't going very fast, mostly suburb streets, so less than 30MPH. About a mile from home my "check engine" light came on, and the car went into limp-home mode.

So I pulled out my old OBD reader, put some fresh batteries in and found that it was throwing a "Turbo Pressure Failure" code (P0299). Called the dealer up, they suggested I get it towed rather than driving it (just in case), calling Mercedes Roadside assistance was a great experience, professional tow truck driver came in under an hour, with SMS alerts telling me when he would arrive.

I was hoping it would just be something simple like a sensor, or perhaps an ECU reprogram. However she's spent two days at the dealer, and they're replacing what sounds like both turbos?! They had to order special parts (flanges etc), so it's taken a bit longer than normal while they're couriered over to the dealer. Hmmm. Is this unique to my car, or has anyone else run into this problem? Is there a recall for this specific engine that anyone knows of? Or perhaps the dealer is just "fixing EVERYTHING" (read that in Gary Oldman's voice) since the car is under warranty?

Nanook

Unfortunate situation but...hmmm...maybe an opportunity to call Renntech ?? for a turbo upgrade

Thimee

Haha, that's tempting - I get the feeling that there is tons more power available on that particular motor. My friend has the GL450 with the same motor configuration, however his one has a quoted 50 extra horses for some reason, probably ECU software configuration?

Though my factory default configuration is pretty dangerous, in the first month of ownership I got 3 speeding fines, arrgh. I had to learn to be a gentle driver with this one... The on-tap power still amazes me, even after several years of ownership. Was driving up in the mountains with friends the other day (Berthold Pass, CO), I casually overtook a slow little Hyundai that was struggling for breath up at altitude. Looked over to see the guy next to me clutching the seat in fear, he didn't realize how easy a big motor makes overtaking in small spaces. Also snow tyres, what a great machine for mountain driving.

Perhaps once she goes off factory warranty in 2019 I'll have to look at the Renntech option...

At least this turbo failure didn't happen while on a long trip, she's still in the shop (4 days now) but once I get her back I'll see if I can chat to the tech to find out exactly what went wrong. Probably metal fatigue? Though I only have 25K miles on the clock. Hopefully there is no "issue" with this particular model of turbo. Guess even big machines such as United 232 fail when metal fans crack and break.

Thimee

A quick update - turns out that turbo replacement is quite a serious operation, involving a complete engine and transmission pull. Glad I have the warranty, this would no doubt be a very expensive operation.

The dealer has been great btw, they have really good techs, service advisors etc. So I'm glad it's in their hands and not some backyard mechanic for something this complex!

Here's a pic that the SA sent me earlier, really interesting to see what is really under the hood!

sonicboom188

Question, did the dealer informed you what might have caused the failure?


Thanks

Thimee

No - apparently there was no visible damage that they could been seen (such as broken vanes or snapped shafts etc.), so this one was quite tricky.

Here's the final scope of work - once they got the parts (of which there were lots of seals and stuff for an engine and transmission removal), it took two days. The dealer did a fantastic job though, no squeaks or rattles, everything looks very methodically put back together so I'm pretty happy with the repair.

I asked out of curiosity how much this would cost in not under warranty, it was about $2,500 in parts and almost $2,300 in labour. Glad I'm covered through 2019

Oh, I'm also quite gentle on the turbos - when I get home there is slow surface street driving, then a minute of idling while waiting for the garage to open etc, so lots of chance for turbos to cool down. Same thing when away, I'm usually in a parking lot looking for spots etc, no I don't believe this was a mechanical failure due to turbo overheating. Mot of my driving for the last 25K since new has been highway, constant 55-80 MPH, occasional overtaking but by and large fairly sedate.