My car lost acceleration while driving why?

Hi, so my husband was driving his Mercedes yesterday on the freeway, he said he was going about 65 mph when he pushed on the gas pedal it went all the way to the floor and the rpms went up but it wouldnt accelerate. He pulled over and turned the car off for about 10 minutes and then it started working just fine. Does anyone know what this could be caused by??

That sounds like a failing transmission.

How old is the car?
Is the Check Engine Light lit up?
How many miles does it have on the odometer?
and, perhaps most importantly…
When was the trans fluid last changed?

There may be other possibilities, but a failing transmission would be my prime suspect.


Truthfully i dont know when the transmission fluid was changed hes only had it for like 2 years. Not sure on the mileage either. He’s not had any issues with it until now though. I really hope its not the transmission he’d have to junk it theres no way we could afford a new trans for a mercedes.

Then the cost of a replacement vehicle is also going to be a problem . The logical move is to pay a shop for a diagnostic to see what really is wrong and what kind of shape this unknown year , ? miles and model Mercedes this is.

How old was it when he bought it?

Sadly, this is probably true.
Just so that you are both aware of it for the next car, trans fluid & filter should be changed every 30k miles. When you buy a used car, if the seller can’t prove–via receipts–that vital maintenance has been done, you have to assume that no maintenance has been done.

Please tell us what year car this is. Our comments will be VERY different for a 2016, compared to a 1990 model year.


Yes, that is an excellent point.

The year is a 2000

Have you had the transmission fluid level and condition checked?

Sounds like a transmission problem to me. Check the fluid and see if it’s brown or black. If so, that’s a huge problem.
Even a transmission with clean fluid can suffer major problems because in this case it’s full of 20 year old seals which influence various pressures and any or all of those seals can fail or weaken with age.

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Unless you have documentary proof that this 20 year old car has had its trans fluid changed 5 or 6 times so far, then evidence of a failing transmission becomes more and more compelling.

For your cars in the future:
Change the trans fluid every 30k miles/3 years (whichever comes first) in order to forestall trans failure. If you buy a used car w/o hard copies of its maintenance, you have to assume that NO maintenance was ever done.