My very reliable GL 550 has started chuddering (if that is actually a word) when accelerating from a stop or at low speed while climbing up a small grade. There are no indicator lights on. My mechanic placed some gas additives to clean the injectors but has not really helped. Other potential problems he threw out there was possible fuel pump, but without any indicator lights illuminated the diagnosis is just guessing.
Any thoughts?
Thanks in advance.
Dave

 

Could be miss fire. Check spark plugs and coils.

 

Torque converter is a possibility at that mileage.

 

Drive train related at that mileage, prime suspect would be torque converter. If it feels like it’s skipping that would be the transfer case chain.

 

For those that remember what it was like to drive a stick (manual transmission),
The chuddering feels like starting in first gear and releasing the clutch too quickly, just before the stall. Or starting in second gear.
Driving this weekend the chudder was felt again at low speeds but not at high speeds climbing hills.
Performance otherwise was been very good.
I noticed that if I feel the chudder going up a steep grade, like on a dirt mountain road, if I manually use the paddle shifter to get a lower gear I seem to be fine.
I know it's difficult to make a diagnosis via the internet but does this sound more like a power train problem (torque converter, etc) or a fuel management problem (injector, spark plug, fuel pump).

Once again TIA

Dave

 

When on an incline, Does it feel like the car is starting out in a higher gear and then downshifting to first in drive or reverse?

 

Yes. Feels like starting in higher gear but doesn’t down shift to lower gear.

 

It’s supposed to take off in second gear.

 

Oh really? I have been wondering about that. There is no sport or comfort setting for the tranny like on my S550. How does one start off in first if they want to?

 

D1

 

I have the 550.

Just so we're all on the same page here, no matter what gear you're in or how fast you're driving, if you double tap the gas pedal twice it will always drop a gear for acceleration purposes, correct?

 

Never tried that…but to be sure just use the flappy buttons on the back of the wheel to manually shift.

when you start off normally downshift one gear, you’ll feel the shift and the center screen should read D1. Which means you started out in second. Other 7G implementations such as the R class has a Sport / Comfort button that in Sport starts out in 1st gear.

 

I assumed that it started out in 1 because there wasn't a sport or comfort button.

 

Has anyone tried Instant Shudder Fixx by Lube Guard in the X164 to improve or resolve these type of symptoms?

I do 100% agree with anyone who says they don't believe in the magic bottle fix, but the reviews on Amazon and YouTube are hard to ignore...

 

i wouldn’t try this. I find the reviews on Amazon and YouTube hard to believe most times.

 

The failing motor mounts on my '14 GL450 caused a shudder on acceleration that went away after 10-15 mph. Then if you were driving at say 45 mph and got on it a little, you felt the shudder. Dealer replaced under CPO warranty Aug 2017 at 46k. Now at 80k with no reoccurrence.

 

Agree. Many of the high ratings sound suspiciously the same and many of the low ones sound like the reviewer didn't follow directions or was expecting miracles for the price of peanuts.
And most liquid fixes just gum up the works to hide, not fix, problems.

 

That transmission will cost you thousands to replace, plus it's a headache considering the electronics have to be programmed to your VIN. Not in a million years would I consider putting additives in the fluid.

 

Totally agree with that, if there is an issue with the internals, there is an issue, needs to be addressed, no magic additives will fix that, fresh ATF is always good but again, if the issue is bigger, it will not cure it.
I`m a bit skeptical about the additives and not using anything, tranny, engine or any other fluids, just do your oil changes, fluid changes in time, keep the levels sufficient and its good. The rest is marketing gimmicks.