I’m still having intermittent start-up issues with my 2008 GL320, I have 207,000 mile with no catastrophic issues, just normal wear and tear.

In Aug. 2014 she went to my dealership for tires and frontend alignment. I got a call stating that they backed into a pole and damaged the vehicle by the fuel tank (left rear panel). They repaired the area and all was good.
Then in Dec. 2014 car wouldn’t start, so my private mechanic (PM) replaced the battery and stated that the fuel pump went bad, replaced them both. One week later truck wouldn’t start again, it was towed back to PM and he said the pump went bad (could have been a defective part) he replaced it.

Jan 2015 I started having slow acceleration (no oomph, when I floored it to access the freeway) when driving. My PM cleans the exhausts system. Got power back but two weeks later truck won’t start again. Had it towed again to my PM, he sent the car to MB dealership close to him, they stated that pump wasn’t installed correctly and generic battery was installed, they replaced both parts and they said that the transmission was going bad and it needed to be replaced at $8,000.

Others have stated that the issue might me slug in the fuel system, dealership stated not likely what is causing the intermittent start-up issues.
Truck runs great when it starts, no error lights. The intermittent start-up occurs about after 12-18 (+/-) start, it then becomes difficult to start; it sound like it’s starting however it never kicks into it actually starting. It can take 10-50 minutes to eventually start. At first I thought it was when the car was hot (after driving), now it happens when the engine is cold. I took the truck into MB to get diagnoses this week after it taking me 50 minutes to get it started and the “Check engine” light came on. MB is saying I need a new turbo assembly because the electronic throttle actuator is bad. Also, there are NO signs of the turbo going bad, I have full acceleration, no smoke, no noise, no oil leaks and no excessive oil consumption and the oil pressure is ok.

What I don’t understand is how the turbo is used during the starting process of the vehicle. I thought the turbo boost power while driving. In short one dealership says its transmission $8,000 and another says turbo assembly at $6,100.

I don’t want to keep wasting money on diagnosing. I don’t think it’s the Turbo Assembly! Can someone explain how the turbo is used during the starting of the truck?

Thanks

 

I would make them agree to refund your money if it doesn't fix the issue. I did the same thing on a repair. I told the dealership what I thought was causing the issue and they told me it was something else. I accused them of throwing parts at the problem and told them if what they were doing did not fix the problem the work they did was no charge. Make sure you write it on the service ticket so you are covered.

I really feel for the diesel GL owners. Just so many problems. My 450 has been the tightest and most reliable vehicle that I've ever owned. It is even more reliable and better built than my 210 E class. Still drives and looks like new. Just love it. The only things I would change would have been to add the tow package and lifetime Sirius subscription when I purchased the car.