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Audi_B6_Fan
25-08-2015, 12:30 PM
Hi All,

First off, new to the forum , so Hello.

Im currently having issue with my Audi a4 b6 2004 avf engine. I noticed that my radiator fan is not working ( 1 big fan for engine and a/c). Im pretty much stuck at the moment. First thing I did is I connected the Fan directly to the battery 12v and the fan kicked in, which indicated that fan should be good. I replaced the FCU (part directly from Audi) and still nothing. I replaced the Thermostat, cooling temp sensor, and still no joy. The temperature is reaching up to 90C and stays there no matter how hard I drive the car or how long its on. So the good thing is its not overheating yet, but I have a feeling from experience that it will soon enough if i dont get my fan working again.
My a/c is not topped up, as due to the Irish weather its not needed :) so I cant tell if the fan is working by pressing ECON OFF. Would someone be able to assist, i also checked the fuse box ( fuse #4 radiator) seems to be ok, maybe its the relay? anybody has any ideas? would appreciate any help before going to audi and pay $$$$$

fourringsrus
25-08-2015, 09:13 PM
Does the engine have two coolant temp sensors, one for gauge and fans, other for ecu, if so I think they both need to be good as they talk to each other via the ecu and everything then works nicely.
Good be miles off, but worth researching
Good luck

Audi_B6_Fan
26-08-2015, 08:09 AM
As far as Im aware there is only one located behind the engine, as on the picture below.
28612

I did some research and cant find any reference if there is a second one. Could someone confirm this?? There is a pressure sensor by the radiator but thats a different story.

zollaf
26-08-2015, 08:34 AM
the fan will only kick in when the engine is hot enough, so has your engine actually got hot enough for the fan to kick in ? if its sat at 90 and doesn't move then chances are its not and you might be trying to fix a problem thats not actually a problem.

Audi_B6_Fan
26-08-2015, 09:03 AM
by saying hot enough, do you know what temp normally kicks in the fan?? i drive 50-60 miles to and from work everyday so engine should be hot enough, however as you said the temp never goes above the 90c mark.

zollaf
26-08-2015, 10:27 AM
when you drive, air is forced through the rad and cools the water.when stationary, air just sitting on the rad is enough to keep them cool. in fact, if you can feel the radiator you will probably find the bottom is stone cold, even after a 50 mile run. thy are built to be able to tow a caravan across the sahara, up a big hill. thats about the only time the fan will kick in. my 80, thats never kicked in, no matter what i do. the needle will need to move to 105 degrees or so at least . its a diesel thing, they are more efficient than petrol engines, less energy is wasted as heat. my 80 even has glow plugs in the heater circuit to warm the water up to get hot air in the cab, i think yours does to. i have run landrovers with no fan at all and no overheating problems. my discovery did get hot once up a very steep slow, low box climb in some woods on a baking hot day. once we got to the top it soon cooled down again.

Audi_B6_Fan
26-08-2015, 11:03 AM
Ok cool, i guess its just the matter of driving the car and see how it goes :) in my previous cars (not audi) i was able to hear and see the fan spin even after the short journey so thats why i was wondering / assuming something is actually wrong. But since the temp is not rising it should be ok, thanks for the reply.

Rob69
26-08-2015, 12:54 PM
Does your car not have the electric fan and the viscous coupling belt driven fan as well ? My passat tdi electric fan never kicks in, as the viscous is always ticking over to some extent, checked the electric and all seems ok, just not enough demand for it in our climate I think.

zollaf
26-08-2015, 01:52 PM
Ok cool, i guess its just the matter of driving the car and see how it goes :) in my previous cars (not audi) i was able to hear and see the fan spin even after the short journey so thats why i was wondering / assuming something is actually wrong. But since the temp is not rising it should be ok, thanks for the reply.
have you owed a diesel before ?

nevo
27-08-2015, 12:21 PM
Get your air con working and it will go like the clappers,do you have a twin set up viscous and electric ?

Rob69
27-08-2015, 12:38 PM
Dunno mind Nevo, my electric never kicks in even when air con is blasting cold, viscous fan seems to cover air con condenser and engine cooling rad ok. Maybe need to go somewhere hot for ultimate test !

nevo
27-08-2015, 01:54 PM
What about stationary? maybe a dumb question you must be stationary to observe!

Audi_B6_Fan
28-08-2015, 03:21 PM
Yes I did, and to be honest I noticed in my previous Audi a4 also diesel that the fan was working after the journey to and from work, so thats why i was wondering if something is not right there.

Audi_B6_Fan
28-08-2015, 03:23 PM
its not the twin set, its the single big fan that works for both to cool the engine and to operate with the a/c. not sure what you mean by viscous?? - like powered by belt of sum??? sorry prob a stupid question.

nevo
29-08-2015, 12:41 PM
its still got a belt it'll just freewheel when conditions are right.