I searched the forum, and could not find this problem mentioned elsewhere. I have a 2002 CLK430 with 97K miles on the odo, and it gets decent mileage, and has under 10K on the plugs, frequent Mobil 1 oil changes, regular air filter replacements, etc. etc.

Here's the problem: I will be cruising at anywhere between 25 and 60 mph, and then push the accelerator to Wide Open Throttle (WOT), or very close to WOT. Almost instantly, the motor slows down, and becomes almost unresponsive to accelerator input. If I hold the pedal at 75% - WOT, it v-e-r-y s-l-o-w-l-y accelerates up to cruising speed. It continues to function this way, from stop light to entrance ramp and all around-town driving.

My fix: stop the car, turn off the ignition and restart the motor. And viola ! Now I have acceleration again, as long as I avoid WOT. And no codes are on OBD.

Any ideas from all you smart mechanics out there? This problem has persisted for a year now, and I find myself (naturally) avoiding WOT, which is a real shame with the 430.

 

Weird.

When cruising, does the transmission downshift at WOT?

 

How many miles on your car? The Mas Airflow sensor can be the culprit in so many situations, I would start there. Replace the whole thing or just the element/sensor at autohausaz.com. If you can't find the sensor on their website, call them.

 

No, it does not downshift. What do you suspect?

 

Step 1 - cleaned MAF - problem persists. On to Step 2 ...
Step 2 - replace fuel filter
Step 3 - replace MAF

 

This thread is continued at http://www.benzworld.org/forums/w208...m-strange.html

 

I had a very sluggish 320 which would not down shift and you had to feather the accelerator to make it shift when you used kickdown, changed the MAF and its like a new car, cost £80 and took about 5 mins to do, error code was on but didnt relate to MAF, can't remember what it read but it didnt mention MAF, it was something like oxygen etc etc