rich4368

It's 7,000 miles and six months old. Check engine light came on this morning. The rpm runs wild and mileage dropped to 16 mpg. Seems like the timing is off. I have brought the car in 3 months ago to report lack of power and slow pickup. They ran the computer back then said nothing wrong. Will bring the car in to dealer later on today and update the post with findings.

Fourdiesel

GL 350 or GL450? your sig says 450 - subject says 350

rich4368

You're right! I returned my 2007 GL450 at lease end and been having the GL350 for 6 months.

So the dealer told me they ran some diagnostics and check all the messages and said nothing wrong. In fact the Check Engine light went off all by itself. What can I say? I feel that sth is not right but can't proof. This was the second time that I brought back to dealer and was told nothing wrong. Will pickup the car tomorrow morning and see.

Pinoy

May I suggest going to another MB dealer next time? I had a similar problem with my previous car, not an MB, and the dealer was not able to diagnose & solve the problem ( 2 attempts ). So, I went to another dealer which resolved the problem.

rich4368

Thanks. That's what I will do hopefully in 3 months when I need the service A. It's a real hassle to have to go opposite direction of my normal commute route to go to that dealer (AutoBahn at Belmont) that I purchased from. I will try a Stevens Creek next time.

I also had the tires rotated & balanced at 6,900 miles. Cost a whopping $98 hope that help the life of tires. Called and paged the SA 3 times to ask for status couldn't reach anyone, complaint to sales and service directors, SA called late afternoon said nothing wrong. This dealership's service is getting worst...

rich4368

Here is the update. Pickup the car and the next day CEL came on again. Brought it back to the dealer and was told need to replace the 'Bluetec Pump'. They have to order that from Germany so will arrive in one week. Will update again when the part arrives and installed. I'm excited since all these mysterious 'lack of pickup' issues that I reported from the beginning might be fixed! fngers crossed.

Fourdiesel

The Bluetec Pump would be the pump that moves Bluetec fluid (30% urea in water solution) from the storage tank in the 'spare tire well' to the SCR catalytic converter that converts NOx to N2. If that catalyst somehow became plugged (hard to see how that would happen since NOx is a gas) then sluggish performance would result. Otherwise, if that turns out to be the real problem, then the ECU may be limiting power based on LACK of Bluetec fluid being pumped. Sort of an artificial 'limp' mode where power is limited so NOx will not be produced.

rich4368

Fourdiesel, you're right on. This is what dealer have done: drained the adblue, replaced the adblue tank and adblue pump, refilled new adblue. As the result, I don't feel the sluggishness anymore, still feel the turbo lag though. I am so glad that I was right all along about the sluggishness, just that without the CEL they would never figure this one out..