Mercedes-Benz Forum banner

Tensioning aux belt.

1310 Views 10 Replies 3 Participants Last post by  ssanmor
Hello all.
I suspect that my 190E 2.3 8v (1992) auxiliary belt is not correctly tensioned, because it makes noise and also "screams" when the car is cold and I press the throotle pedal suddenly, for example.
It has a kind of pipe pointing upwards with a screw in it, besides the power steering reservoir. Could anyone tell me if I can tauten the belt more, simply by tightening this screw or is it a bit more complicated?
Any help is very appreciated.

Thanks!!!
1 - 11 of 11 Posts

· Registered
190e 1.8 Manual 91
Joined
·
8 Posts
You can adjust the belt by loosening the big nut on the tensioner at the front of the engi...

You can adjust the belt by loosening the big nut on the tensioner at the front of the engine and then turning the long adjuster nut at the top of the engine.
If the belt is cracked you might want a new one.
I have read other people say that the tensioner can stop working so if you turn the adjuster and nothing happens that is your problem.

There is also a shock absorber that stops vibration in the tensioner and when these wear they rattle.
You might be able to see it rattle in Drive with the handbrake on.
 

· Registered
Joined
·
96 Posts
Discussion Starter · #3 ·
Thanks, Duncan.
The thing is that I took the car to be repaired a few months ago becaus...


Thanks, Duncan.
The thing is that I took the car to be repaired a few months ago because the fan clutch didn't engage. When they returned me the car, the fan worked OK, but the noise appeared. I took it to be revised. They removed and refitted the belt but now it is the same or worse, so I suspect (hope) that the belt is simply not correctly tensioned.

Thanks!
 

· Registered
Joined
·
96 Posts
Discussion Starter · #4 ·
So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should...

So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should I meanwhile press the tensioner against the belt or something so it doesn't loosen even more or, on the other hand, it is enough to leave the tensioner free and tighten the vertical nut in order to tension the belt?
Perhaps too a basic question, but I haven't done this operation never in any car.

Thanks!
 

· Registered
Joined
·
96 Posts
Discussion Starter · #5 ·
So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should...

So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should I meanwhile press the tensioner against the belt or something so it doesn't loosen even more or, on the other hand, it is enough to leave the tensioner free and tighten the vertical nut in order to tension the belt?
Perhaps too a basic question, but I haven't done this operation never in any car.

Thanks!
 

· Registered
Joined
·
96 Posts
Discussion Starter · #6 ·
So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should...

So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should I meanwhile press the tensioner against the belt or something so it doesn't loosen even more or, on the other hand, it is enough to leave the tensioner free and tighten the vertical nut in order to tension the belt?
Perhaps too a basic question, but I haven't done this operation never in any car.

Thanks!
 

· Registered
Joined
·
96 Posts
Discussion Starter · #7 ·
So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should...

So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should I meanwhile press the tensioner against the belt or something so it doesn't loosen even more or, on the other hand, it is enough to leave the tensioner free and tighten the vertical nut in order to tension the belt?
Perhaps too a basic question, but I haven't done this operation never in any car.

Thanks!
 

· Registered
Joined
·
96 Posts
Discussion Starter · #8 ·
So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should...

So If I loosen the big nut in the tensioner and adjust the vertical nut at the top, should I meanwhile press the tensioner against the belt or something so it doesn't loosen even more or, on the other hand, it is enough to leave the tensioner free and tighten the vertical nut in order to tension the belt?
Perhaps too a basic question, but I haven't done this operation never in any car.

Thanks!
 

· Registered
2001 PT Cruiser
Joined
·
6 Posts
190E tasks

Just a little side note, based on your posts...I just bought an '86 190E. As usual, my next purchase was a Haynes manual to go along with it. The current US manual, as far as I know, is for 1984-1988 models and may be very helpful in answering your questions. Belt tensioner adjustment is covered in Chapter 12 ("Electrical System"), part/section 6, on page 231. For later 190E models, the Haynes UK site shows a manual available for 1983 to 1993 model 190Es. Not knowing your location, I thought I'd throw that out to ya'. Hope this helps, as I've found the Haynes manuals very useful for a variety of tasks.
 

· Registered
190e 1.8 Manual 91
Joined
·
8 Posts
You just undo the big nut at the front. Then turn the adjuster one way for tight the oth...

You just undo the big nut at the front. Then turn the adjuster one way for tight the other way for loose. You should feel it getting tighter
 

· Registered
Joined
·
96 Posts
Discussion Starter · #11 ·
Bad news

Last friday I took the car to a Mercedes dealer to have a look at it: the told me that the belt was too loose and, as they hadn't time to tighten it, they explained me just the same as you. I took the car to a local garage (non-mercedes): they loose the big nut, turn the vertical one and... the screw loosed totally from the tensioner piece. Now the belt is much more loose and the car screams as mad. They told me to take it to Mercedes because it seems complicated to return the screw to its place.
Perhaps I will have to change the tensioner and shock absorber at Mercedes. How much do you calculate???
Thanks!
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top