w211 fan noise

[MorrieC4rbrook]

Good morning. just to see if anyone can help me. W211 seems to go into a purge mode where the fan makes a loud up and down noise. The car goes into protection mode and shows an eps error. I have had a diagnostic done and has shown no major errors. Had any error codes cleared and car serviced. Ok for about a week and started again. unfortunately it seems to happen more at night. The car does ample motorway miles every day.

 

[mersum1es]

Low voltage. Check battery/leads/earth straps/charging voltage/aux battery (if any, again not full car info given )

 

[MorrieC4rbrook]

Low voltage. Check battery/leads/earth straps/charging voltage/aux battery (if any, again not full car info given )

I have had into the garage, would this not be picked up on diagnostics? What more info do you need for car?

 

[MorrieC4rbrook]

Ok I will try that, but I would have thought the diagnostics would have picked this up. What other info do you need for the car?

 

[mersum1es]

Depends on diagnostics. Not all devices read MB properly. SDS preferred. If car is at limp mode, there IS fault code, as well as ESP error in display.

For example model year, now we don't know if your car has SBC system or not, and thus no way of knowing if aux battery exists.

Measure current draw as well, since sitting overnight is causing problems.

 

[MorrieC4rbrook]

car is e280 55 plate automatic. it doesn't go into limp mode, just wont start unless you let in go through this noise sequence which i cant let it do at night.
I will try and get it tested and let you know.

Thanks

 

[mattkh]

.........just wont start unless you let it go through this noise sequence.

Thanks

How long does this noise sequence last if you were to let it carry on.

 

[MorrieC4rbrook]

How long does this noise sequence last if you were to let it carry on.

The noise goes on for about 20 minutes to 30 minutes. The car starts ok after it. However I have another fault now which is preventing me even turn the key.
Nightmare.