1e63sAMG

I got off work and started the car and immediately noticed almost no power when accelerating. OBD scaned no code and no CEL. Turned the car off and on and same issue. The car has maybe 20% power when accelerating. I tried to floor it and it picked up and got a random full power. Slowed down to stop and back to same limp mode. Even when in manual mode when flooring the car it does 0-20 in 5 seconds and then randomly either 100% or close to 100% power. When in neutral the car revs all fine and seems to be all fine. When in drive doesn't want to move.

Second owner, never modded. Have had the car for almost 2 years. 87k miles. About 6 months ago had changed all the plugs and 3 coils.

Any idea what's wrong?

PeterUbers

what is the whistle?

I wonder if your accelerator pedal is bad ..

they are cheap on eBay used

Do you have a sprintbooster?

also is the hood slightly open?

have you looked for animals in the intake or something blocking the throttle body?

bdubs

I had an ignition coil going bad that wasn't throwing a CEL but I was noticeably down on power. It would come and go...then eventually was bad enough it would throw a CEL. Prior to the CEL, though...I wasn't anywhere near as low on power as you...maybe 20% down, it just felt sluggish and "off". When the CEL popped on, the car bucked like crazy going on/off power. Hopefully, you can track the issue down quickly.

1e63sAMG

I am waiting for a CEL. When I accelerate it literally doesn't want to move and then suddenly it's like I'm launching the car with full boost until I come to a full stop or off the throttle. And the reason why I don't think it's coils it's because when in neutral it revs like there is nothing wrong with the car. Only loosing power when on load.

I.T. Guy

Sticky throttle body?! Or faulty drive by wire connection? Or gas pedal sensor thingy that tells how much throttle to give?
I don't know where any of these things are, but if I went old school on what you are describing I'd be looking at carburetor throttle blades springs and and linkages all the way back to the gas pedal too.
Can you scan throttle position etc. with a hyper-tech?

1e63sAMG

All of that makes sense could possibly be a throttle body issue. It feels like the engine is not having enough air or gas. I have talked to couple of mechanics and will eventually take it in. I went ahead and put some Jectron fuel system cleaner and pumped full tank Chevron to eliminate the bad gas issue.

Also to mention I pulled the battery and let it sit for an hour and after reconnecting it the car drove all fine for about 20 miles.

PeterUbers

Whistle?

literally takes 3 min to take the pedal out and disconnect -- make sure you leave door open for 5 minutes before going in and taking it out

PeterUbers

https://mbworld.org/forums/e-class-w...al-sensor.html


https://www.ebay.com/itm/18418748825...mis&media=COPY

1e63sAMG

I could look at the pedal but if it was the pedal or throttle body related wouldn't it happen when on neutral also? Literally when the car isn't moving and I shift to neutral it starts revving all fine and it limps when shifting back to gear.

PeterUbers

Not necessarily but to each their own

and will you discuss the whistle or was that a typo?? Lol

1e63sAMG

The whistle is at low RPMs not at idle, more like when you are at 10-20% on throttle and when there is load on the engine. Almost feel like it's when the turbo is spooling. When the RPMs are high it's either gone or not loud enough to be heard. Sounds similar to having a broken supercharger bearing on M113 (E55).

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PeterUbers

vacuum leak possible; also do a tcu reset

https://mbworld.org/forums/c-class-w...on-sensor.html

Tcu reset:

https://mbworld.org/forums/c-class-w...tcu-reset.html

GinDistiller

Invest in an iCarsoft MB2 scanner instead of waiting for a CEL. They are all of $130 on Amazon (less than an hour's diagnostic at a dealer...). These actually scan the ECU, not the OBD2 portion which I have found to be very latent in Mercedes to trigger a visible CEL. Almost guaranteed you'll have some kind of pending or active code with how you describe it driving, and you can/should also scan the TCU which this can do. I have found it invaluable while owning German cars.

If you don't find any error information, go into the OBD2 menu and you can visibly graph certain channels while driving. It's not quite datalogging, but if you're getting a throttle spike when this happens it will be very obvious. Or if timing is being pulled massively for some reason etc.

My vote is likely the gas pedal, but I would also check the ECU harness for oil intrusion which is very easy to do and a common problem that can cause all sorts of electrical headaches if it hasn't been caught in time...

Best of luck!

Baltistyle

It’s a classic symptom of coil pack. Many times when failing they will work in some rom range or at some temperature but not all. Likely the whistle is from the turbo because the coil is catching on a starting higher rpm vs “ramping”.