tranmission problems? / acceleration problems?

Question

hey all , i have a mercedes 350sdl. it has lot of miles on it (over 175k) but it still runs well. Today I noticed something odd. When I would accelerate above 40/45mph, i would hear a hissing sound, sort of like air hissing out of a leak. Also the acceleration wasnt working correctly, I could barely get above 50mph - the rpm was spinning up but the car wasnt accelerating like it should.

I took it to the mechanic who knows the car well, and he found I had very low tranmission fluid. We filled that up and I did some test driving in the city around his shop, and it ran normally - I was very pleased. He told me if it went back to the same probably there might be a fluid leak.

But when I got onto the highway to go home, my acceleration felt not as strong as it should when going for exapmle 50-70mph. It was fine going from stop to go, however.

Any ideas? and I still don't know what that hissing sound from earlier was.. but I haven't heard it since,

Thanks.

the acceleration problem on the way home was minor ... nothing like how it was accelerating before I got the fluid filled up. I would hit the gas pedal and the engine would rev up to 3000 or so rpm and yet the car would only actually accelerate to around 20mph... i wasnt going above 30mph until I got the fluid filled because I didnt know what was wrong and didn't want to damage anything.

Anyway, what I felt on the way home was nothing like that... the car seemed to be running normal, just the acceleration from a high speed to a higher speed seemed a little slow - like it was not getting enough power.

where would i go to get the tranmission inspected, and other parts in general... not like a $30 jiffy inspection but a more thorough one.

I trust my independent mechanic he knows foreign cars well, but it would be nice to get a second opinion from a more professional/organized place (but not like a jiffy type place)

thanks

Answer 1

It is transmission problem,take it dealer and daignose and he will tell right answer, if it need new transmission get it done from dealer only, don't go any there else, because i got same problem and i went to aamco transmissions and they told 1500 first and when they opened transmission they told 3300 which is just 3000 in honda dealer and aamco transmission is not good in fixing transmission for imported cars.

Answer 2

I would have a certified transmission specialist do a diagnostic on the vehicle to make sure there is not a leak. You don't want to wait for the symptoms to occur again if there is a slow leak. That would put uneccessary wear on your transmission and might cause extensive damage.

If may be that because your car is older and has a lot of miles that your transmission fluid is oxidized. In that case, you would need to totally replace it and keep checking it at regular intervals.

Always do a filter check, too!

Here's a helpful site:
http://www.samarins.com/maintenance/simple.html#automatic

Answer 3

You didn't say whether you had the transmission filter changed.
If you haven't changed it, have it flushed and change the filter.
It sounds like it is all in the trany. Also check the lines going to and from the transmission. Check it for leaks. And check the vacuum line when the car is running to hear if it leaks.

Answer 4

Take it to a transmission shop and they will test the pressure regulator and check a couple other parts like the gear pump and the fluid pressure governor. They can also change the fluid and filter.....