MB Fans,
I have a 91 560SEL -- 156K -- all of a sudden I lose power and can't go over 40 MPH, and my limited slip differencial light goes on and off....when it goes on, it feels like a clogged gas line and I lose power. Seems to take off from a stand still OK, but can't really build up speed past 35 Mph before the light goes on....When in park the engine has no problem reving and seems to be getting plenty of fuel....
I think it is some kind of modulator or vacuum line to the tranny or throttle valve switch...???

Any thoughts would be much appreciated...

Benztime...

 

intermittent problem means something is loose.

was the throttle valve connector clean and tightly fitted?

does turning off the engine and restarting corrects the problem?

 

HI Sleepwalker,
I will check the Throttle valve connector but restarting does not help. It idles fine and will rev fine, the power loss happens when I try and go above 35 MPH and then the limited slip light comes on and I lose acceleration.
Thanks Benztime

 

we got such similar problem posted here before, but i forgot which thread.

try searching more.

are your tires of the same size? please check if others are worn out or otherwise..

 

Hi Sleepwalker,
You were right on the money -- I had replaced a front tire temporarly and it was larger in size than the other 3. Odd thing is that it was picked up by the limited slip sensor in the rear. I replaced all 4 tires (needed) and it solved the issue.
No need to check anyother area...

Thanks for the tip and advice.

Benztime