i have a 98.5 1.8t a4. my secondary fan is not working. say your looking at you engine with your hood popped its to the left were the turbo is. At first I thought it was the fan that was broken so i replaced that. Then it still didnt work so i went to this audi tech and he said it was due to a fan switch sensor( the one that screws into your radiator) so i replaced that with the lower fan switch sensor( turns on at lower temp than stock) and still dosnt work? this might be the reason for my car overheating so please help and thanks.

 

i could be because the coolant in the radiator is not circulating, due to possibly a faulty water pump... impellers go bad.. hey, arent you already posted on here once about that problem??

 

Yeah I have a post , but that one was cause my car is overheating, and this post is for my fan, since not to many people write the more help the better. I wanted to know If there was some other kind of sensor or something that turns the fan on?

 

What the hell is up with these SPAMMERS! I have seen a lot around here lately.

Anyway, the fan turns on when you use your Air Conditioning. It shouldnt cause overheating when not on, unless your a/c is on. Have you tried turning your a/c on and seeing if the fan works?

 

yeah i know that it turns on when using the AC and mine work when AC is on, but i also thought it is supposted to turn on at 102-91 deg celsius, i even go the lower temp one 93-88 deg celsius.( got mine on germanautoparts.com under cooling, called switch radiator fan? so i dont know why its not turning on but hopefully someones does, ha. one of my friends has a vr6 gti and his kicks on all the time, even when he turns his car off it kicks in a few times to cool the engine??

 

So the a/c fan does work when a/c is on. Then I would suspect other problem parts. Could be the water pump. But you may have a bad fan clutch. Its the other fan and it is mechanical. Please describe how it starts to overheat. Does it overheat immediately, in 5 mins. etc.

 

yeah the car heats up fairly quick, it gets to the half way mark and stays for a minute or two and then the temp keeps going up? yeah im gonna get a new water pump and im gonna look into the fan clutch. so i would say it takes about 10 minutes to overheat, weird part is if i let the car idle it takes longer to overheat then when driving?

 

Definitely sounds like a water pump issue. If you take the thermostat out and look inside, you should see the water pump impeller, if it spins freely, then it is bad, if it wont spin, then it should be good. You may also have a blown headgasket. Check the water pump impeller first.

 

yeah im sure its my water pump, and theres no way it could be my headgasket i got so much work done at 95,000 miles( and now its at 120,000 miles) heres the list of what i got done:
timing belt, drive belt, headgasket set, head bolts, spark plugs, intake valves, exhaust valves, hydraulic lifters, PCV valve( 2 part), Alc belt tensioner, timing belt idler, valve guides, front engle seals, exhaust studs, coolant flange( replaced that again), coolant, oil change and new filter.
Also the car fires up and drives perfect it just gets hot so its the water pump for sure, and im getting my car vag scanned in the next couples days to check for codes. And again thanks for all the help

 

Hi. So you found out it was the water pump?
When I initially read your problem I thought I was having the same issue. the aux fan not working (already replaced it too...) also already bought the switch (but have not changed it yet) but the engine also gets overheated but only when the car is stop for long periods of time, if I start driving the temp gauge goes to normal (middle of range). somebody also told me it could be the fan clutch or water pump, I dont think (and I hope) it is not the water pump as the temp is normal when the car is moving, it only gets over heated when stop, how can I check the fan clutch? Is there a map or directions how to change the water pump?