I have owned my bluetec for 6 months and the same issue is present. When i am coming to a stop by coasting, engine deceleration, and then i roll through a green to take a right hand turn, i hit hte accelerator and the car is almost like DEAD. no shudder, no issues EXCEPT it takes like 2 seconds for anything to happen, then a MASSIVE rush of power.

It only seems to do this if i let the truck coast almost to a stop and then want to get back on the throttle.

Ideas?

 

Welcome to the wonderful world of turbo lag. This is normal. The engine has been at idle and the turbocharger has stopped spinning quickly. Your transmission is in a higher gear for coasting than you need or want. You hit the throttle and the engine needs to produce exhaust pressure to spool the turbo and the transmission needs to downshift before you can get any real thrust. The tip here would be for you to paddle shift to a low gear in advance of coming out of the turn to hasten this process just a bit. Of course, then you'll be in a manual mode for a few seconds so you might have to upshift using the paddle. Lag from one larger turbo is typical, but oh that sweet torque when she hits...

 

I think we have the same car. 2013 ML350BT and have the same PIA issues.

Everything else is expected, at coasting speed, merging and overtaking performs as expected. Its a 5000 lb SUV and not sports car but that tubo lag at street speed is really annoying to the point that I'll will never go back to diesel. While the range is pretty awesome vs. petro, where I live there is a premium on diesel over premium gas. Basically, my cost per mile is about the same had I purchased a 4matic. If I had to do it again, the 4matic would have been a better choice.

The two things that really annoy me about this car is when driving:

The turbo lag that you experience. For me, it usually happens when trying to switch lanes in street driving. In city driving its very typical to be behind a car that suddenly slows down. You slow down to about 15mph, then sees right lane open, but a car is fast approaching. You signal, then floor it...the damn thing just sits there...turbo spools then you get a rush of power. Sometimes too much power then brake again.

The other thing that I noticed even with 2014GLE petro is during a K-turn. My street is 2-way traffic and sloped towards the sidewalks a bit. I would make the 1/2 turn (now facing and sloped towards the sidewalk), full stop then put to reverse, gas it and nothing happens (it sometimes rolls forward even) until the transmission engages, then depending on gas pedal position, you may get a jolt in reverse. Lag isnt as obvious going from reverse to drive, by mostly from drive to reverse. Almost feels like Drive, Neutral, then Reverse. Its all fun and dandy until you see a car coming to take your parking spot.

I read somewhere that there may be a software update for the lag when shifting from drive to reverse, but the other problem is turbo lag explained well by the previous poster.

I have an engine light appointment next week, I think this time I will have a mechanic ride along to replicate the problems. Hopefully they have a software update to reduce the lag instead of just saying that everything is normal. Maybe I'll have him do a K-turn on 11th ave when cars are coming and the lag is pretty scary.

Any creaking in your dash and radio area? Got a fix if youre interested.

 

Yes to the creaking tip! ( thread hijack)

I think I read once about the drive reverse delay, research TSB or the forum so you know the answer and how to direct the dealer, imho.

Agreed, the dreaded lag hits under the low speed cruise to merge scenario in alarming way. Still, I really like this big boss truck.
Except now I'm hearing creaking...

 

This will not eliminate all the creaks, but may reduce some by the radio and HVAC area.

Hard plastic in contact with another hard plastic surface will creak. For me, the flat ledge below the LCD(between the two vents), silver plastic frame around the radio, black frame around the HVAC control, and center console silver frame will creak by just pressing it with my finger.

Youtube ml350 radio removal for detail, but basically remove silver radio frame by pulling it up from bottom right corner first. 4 metal spring clips go into 4 holes to hold it in place. Found one of my clips rattles and needed minor adjustment. I used WD-40 on a Q-tip to coat(lube) all contact points including the clips and ledge sides. That eliminated the creak coming from the silver frame and ledge.
Pop out the HVAC control (also 4 clips, a little more care is needed). Black frame with the two large knob cut-out is held by 2 screws. Once that is removed, clean and lube the part that touches the button module. This is less successful because the button module is hard plastic and snapped on the housing (didnt want to mess with that).
Radio removal is pretty easy as per video. Its also a CD holder, so its pretty heavy. Somewhat surprised by the amount of insulation behind the radio. Radio slides into a metal track using two round metal guides. While it fits nicely, there is some play especially metal on metal. I would guess over a bump, it may cause a tap. Instead of using double sided foam tape (too thick) , I used double sided tape that comes with a window insulation kit. It gives a little tack and cushion on the two metal round guides. Then make sure the anchors that lock the radio in place is nice and tight before tightening the screws.
Everything pops back in place after a thin coating of WD-40 on all internal contact surfaces.

Middle console. Just sprayed some WD40 on a business card and slid the card between the cracks where the creak is coming from.

Yeah, we need to do this on a $60k car. I realized there is also alot of creak from the center display (rmp and speedometer gauge). Those silver accent pieces just snap onto hard clear plastic. Just push it with your fingers and you can hear the creaking. Had a 2014 GLE loaner, it was alot more solid. Didnt want to blast it with WD40 and risk getting some inside the glass....sorry ....clear plastic. Still working on a solution.

Maybe I'm getting use to the car, or maybe its the placebo, but I have less of that Japanese car sound.

4 things I keep in my cars at all times..multi head screwdriver, duct tape, flashlight, and WD40.

 

You can potentially save the world with duct tape.
Thanks, now I have a new project of playing with my plastic trim this weekend.