My 190E engine noise become obvious if the car travel above 100 KM/h, but the loudness
generated is inconsistence, like a waveform, high and low. Anything below 90km/h is perfectly smooth. Any idea what to look for ? BTW, how do I check the fan belt is
at right tension.
Any help will be appreciated.

Have you checked to be sure that the coolant fan is turning off when the engine is cool enough? If the fan is on all of the time it will be noisy.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Yes, the coolant fan is off when
engine is cool, I have try to switch
off the air cond but no change.
The aux fan is a bit noisy but it is consistense.
Beside that noise, when the car travel
down hill and I just apply little presure
on the accelator, a loud engine sound is also generated (sound like air intake).
BTW, the filter is clean and both motor mount are new.
Could it be something relate to the belt tensioner ?
Thanks in advance.
AL

[This message has been edited by altan (edited 05-28-99).]

Does the noise occur in any other gear at the same engine speed? In other words is the noise related to the speed of the engine??

Yes, the noise become obvious at 3000-3500
RPM while car travel at 100-120 KM/H.
I have not try to shift to lower gear
at that speed.

I know this is hard to diagnose
but is there any proper way to
trace this type of noise.
It happend when the car travel
above 90KM/H and then release the
accelator. I tried shift to N (idle RPM),
but same thing.
Could this be the rear diff or wheel
bearing ?.
Thanks you.

The diff's are known to fail.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Assuming the diff is failed, can it
be repair or I got to replace it ?
Is this a major repair and what is
the expected cost ?
Thanks Benzmac again for your help.

[This message has been edited by altan (edited 06-03-99).]