Justin9212

We are planning on having a 3rd child in the next year or so. With that comes the need for 3rd row seating. I once owned a Chevy Tahoe and the 3rd row was a joke, also it averaged 14mpg, so I'm not doing that again. I really was considering the ML diesel, but it does not offer 3rd row. Now I'm looking at the GL and like everything about it more anyway. I'm looking for an 07-09 because depending on miles that is what I can afford. Any of them will be over 100K miles. I am a mechanic by trade, I own a small German auto repair shop.

With that said, what do I need to know about the 07-09 GL diesels?
What changes happened between the years?
What are the common failures?
Just looking for first hand factual answers and experiences. Not what you have heard or read online.
Thanks guys!

N_Jay

I think it is all there in the threads.


My personal experience is with a 2008 I bought last January with 96K, and now have 113K (Very early '08, as I was looking at an 07 also that had a production date only 1 month earlier)
I had the Glow Plug model show a failure as soon as I went below freezing on the way home. My guess is the module had actually failed earlier, but the car was never below freezing on TX.
Common problem, easy fix.
I have a very small oil leak. (Guessing it is either the turbo intake or the oil cooler)
The dealer tried to tell me I had a BIG leak in the cooler when I accidentally left the oil filler loose and dripped about a 1/2 quart down the side and under the engine. (I wonder how many oil cooler failures are misdiagnosis?)
The third row is a lot more usable than most, but not perfect in how you get in. (Has to be right side, and seat has to be able to tilt forward.)
Third row even fits adults, and the extra moon roof helps to make it feel more comfortable back there.


Biggest change is that '09 got the urea tank and lost the spare tire.
We tow, so I did not want to be without a spare so I targeted '07 and '08 cars.
Knowing what I do now, I would have been less worried about the '09 and could have hung a spare on the trailer.

SmokinReefer

Be prepared for the dreaded oil cooler leak and its $4,000 repair bill. It can be an annoyance for months, but it will get worse and require repair.

Be prepared to replace the heater in the AdBlue tank. That will be another $1,500 when the CEL comes on.

And for some reason I've had to replace a fuel pump in each of my three diesels within the first 50K miles. I just took delivery of a new gasser because of the diesel repair costs. I did keep my 2010 diesel with 107K miles though.

Maintenance costs are high on these things when the miles get high. You need to get an extended warranty as it would eventually pay for itself. But with my experience, I would never buy a newer Mercedes diesel with 100K miles, unless I was a good German import mechanic!

N_Jay

If you want to be well schooled, you need to review both the GL320 (X164) and ML320 (W164) forums, as well as the Diesel forum.

Just remember, that a lot of people without problems never participate. These types of forums provide a good understanding, but often are biased a bit towards the worst experiences.

Since you have a German Auto shop, you should easily handle any of the issues that come up.

Fourdiesel

For some real world / real time repair data go here: http://www.truedelta.com/

Justin9212

Do the transmissions hold up well? And transfer case issues?
Is the 07-08 preferred over the 09+ or the other way around?
Does fuel economy change between the two?

N_Jay

The later Bluetecs get a little better mileage, but I think the improvements may be after 2009. (Check the spec numbers)


I think the trans are all the same. Lots of people here with well over 100K and no drive line problems other then a front differential bearing issue that a few report. (no personal experience)

BlownV8

The transmission will suffer from a bad turbine speed sensor or a bad valve body. It's around $1K if my memory serves me correctly. I have around 160,000 miles and no issues to report on the tranny. I have a 450 but I believe the transmission is the same other than the transmission control unit.