# My car lost acceleration while driving why?

**URL:** <https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395>\
**Category:** Maintenance/Repairs\
**Tags:** mercedes-benz\
**Created:** [August 31, 2020, 2:47pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395 "2020-08-31T14:47:01Z")\
**Posts on this page:** 11\
**Page:** 1

<div class="post-metadata">

**Author:** ![mrswendy84\_170404](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@mrswendy84\_170404](https://community.cartalk.com/u/mrswendy84_170404)\
**Post date:** [August 31, 2020, 2:47pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/1 "2020-08-31T14:47:01Z")

</div>

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??

---

<div class="post-metadata">

**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [August 31, 2020, 2:58pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/2 "2020-08-31T14:58:00Z")

</div>

> [@mrswendy84\_170404](#):
>
> the rpms went up but it wouldnt accelerate.

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.

---

<div class="post-metadata">

**Author:** ![mrswendy84\_170404](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@mrswendy84\_170404](https://community.cartalk.com/u/mrswendy84_170404)\
**Post date:** [August 31, 2020, 3:20pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/3 "2020-08-31T15:20:04Z")

</div>

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.

---

<div class="post-metadata">

**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\
**Post date:** [August 31, 2020, 3:23pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/4 "2020-08-31T15:23:40Z")

</div>

> [@mrswendy84\_170404](#):
>
> 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.

---

<div class="post-metadata">

**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [August 31, 2020, 3:25pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/5 "2020-08-31T15:25:33Z")

</div>

> [@mrswendy84\_170404](#):
>
> hes only had it for like 2 years

How old was it when he bought it?

> [@mrswendy84\_170404](#):
>
> 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.

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.

---

<div class="post-metadata">

**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [August 31, 2020, 3:27pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/6 "2020-08-31T15:27:11Z")

</div>

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

---

<div class="post-metadata">

**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [August 31, 2020, 3:42pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/7 "2020-08-31T15:42:41Z")

</div>

> [@texases](#):
>
> Our comments will be VERY different for a 2016, compared to a 1990 model year.

Yes, that is an excellent point.

---

<div class="post-metadata">

**Author:** ![mrswendy84\_170404](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@mrswendy84\_170404](https://community.cartalk.com/u/mrswendy84_170404)\
**Post date:** [August 31, 2020, 5:52pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/8 "2020-08-31T17:52:51Z")

</div>

The year is a 2000

---

<div class="post-metadata">

**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [August 31, 2020, 5:54pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/9 "2020-08-31T17:54:42Z")

</div>

Have you had the transmission fluid level and condition checked?

---

<div class="post-metadata">

**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [August 31, 2020, 6:21pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/10 "2020-08-31T18:21:26Z")

</div>

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.

---

<div class="post-metadata">

**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [August 31, 2020, 8:48pm UTC](https://community.cartalk.com/t/my-car-lost-acceleration-while-driving-why/169395/11 "2020-08-31T20:48:57Z")

</div>

> [@mrswendy84\_170404](#):
>
> The year is a 2000

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.
