D_Mos

Recently i brought my car (2004 E500 4Matic) in to change my oils (motor and transmission). After the oil changes i asked the mechanic if he could check for any error codes and to tell me exactly where my ESP and ABS problem was coming from. Right after he unplugged his scanner and shut my car off the fan just kicked off at full speed.... Like a jet engine. It seems to only do it when the car is shut off and stops the second i put the key in the on position or start it and will immediately start back up when i put the key in the off position and will not stop.... Anybody have any idea what could be the problem? On another scanner it stated that the engine was requesting that the fan run at %100 of its speed.

Thank you.

D_Mos

Turns out I had a broken relay still connected which was causing all kinds of errors. Thankfully i changed it and it resolved ALL my issues

PortAxePlayer1

Good Thing it was only a relay.

I had the same thing on my '06 E350 about a week ago. I inspected the coolant reservoir and to my shock I found oil in it! The fan wouldn't always turn on after the car is locked but sometimes it did it.

Turns out it was a defective Oil Cooler because the engine started to run hot.

Surfer69E500

D, my 2004 E500 just started doing the same thing. Can you elaborate on which relay you are talking about? Thx.

Plutoe

what is your VIN????

Surfer69E500

Plutoe, are u asking me or D?

Plutoe

either or it does not make a difference regarding who wants an answer!

Surfer69E500

I'm WDBUF70J94A450990

D_Mos

it's one of the 3 relays in the fuse box. Front driver side one. I unplugged them one by one and when i unplugged the right one the fan immediately shut off.


If that doesn't work you should check the fans connection. Maybe the module on the fan no longer works like it's supposed to. If that's the case i'd like to tell you right away Mercedes doesn't sell the module separately ($900-1000 for the whole fan)