Fan is always on and engine idling too high

[motah33]

I was talking to my dad who has an Audi 2.0e from 1992 (I presume it's an Audi 80). He said that the fan is on, and stays on, when the car is started. It's idling to high as well. Any ideas as to what might be happening?

Thanks

MT

[scotty33]

Hi

The fan could be due to a switch problem, usually a 3 pin switch mounted on the radiator. If the car has aircon, it may be the case that the fan runs all the time that the aircon is on.

The high idle could be a sticking Idle Stabilisation Valve, these tend to get gunged up with oily deposits from the crankcase breather system, this can be cleaned out by soaking the mechanical end in petrol or carb cleaner. (A new one is quite expensive).
I guess the throttle cable could be poorly adjusted - too tight, or there could be an air leak somewhere on the intake system - split hose etc but this usually causes the car to run a bit rough?

[motah33]

Hi,

Thanks for the reply.

The car does have aircon but I don't believe this problem with the fan as occured before even with the aircon on. I'll ask my daa to check the switch on the radiator. Good point about the Idle Stabilisation Valve.

I think both things seemed to have happened at the same time which is why I was thinking maybe they're related but I'm not sure how. I remember the ECU on the car had to be replaced many moons ago but I don't know if any of this is contriolled through the ECU.

Regards

MT

[Wings]

I have an Audi 80 Avant -94...
I have replaced a whole lot in the engine, but it is still fluctuating RPM when passing 1600 on to about 2500. Less or more is constant.
But as an reply to this thread; I have also replaced the rubber-sole between the TBI and the intake-man. Even though it looks fine, there will be microscopic craks after a while. Even though it will cost a few here in Norway, when replaced it will last for at least 250.000 km, so it's well worth trying. Any leaks on this WILL result in high idle and poor gas-mileage.

Just my 2cents...

[Wings]

...oh, sorry forgot about the fan.

Check your temperature-sensor...if malfunctioning, the computer may act as though the engine is running hot all the time...(or cold for that matter).
Inexpensive both to test and to replace.

[motah33]

Thanks for the reply.

I think my dad was talking about looking at the temperature sensor, so hopefully that would be an easy fix for the fan problem.

As for the idling... can you tell me what TBI is?

[Wings]

TBI = Throttle Body Injector.
Aka, not an regulare carbourator and not entirely injector, kinda half-*** both.
So check the rubber-sole between the "carbourator" and the intake-manifold.