OK!
Went to a radiator shop, they looked at it for free and told me my radiator is like plugged up so bad it has to be replaced. Also my fan doesnt come on when it needs to. hmm the fan problem only happened really recently. I ordered a new radiator which i'll install myself, but why doesnt the damn fan come on??

I was wondering if these had anything to do with it:
http://www2.discountgermanparts.com/parts/parts1/discountgermanparts/wizard.jsp?year=1985&make=AU&model=COU--001&category=G&&part=Auxiliary+Fan+Switch

and if so how do i replace them and which do i need?

car is 1985 Audi couple GT.


ahhh something after another.,... hate this car.

If the radiator is blocked then the then the switch is not going to get sufficient heat to turn on. According to BlauParts the standard thermoswitch should be two prong 82°C.

You should also flush out the system as you could have too much rust and scale that could clog up your new radiator.

whats the easiest way to flash the system?

You can probably hook up some sort of a flush kit. Prestone has one and they also sell the special engine flush. It supposed to dissolve the rust and scale. Be careful with the Super Flush and follow the instructions carefully. The problem with Super Flush is that if you leave it too long you will discover leaks in places that you couldn't even imagined. You can also use a plain garden hose hooked up to the heater out flow and the other end out on to the ground or a bucket.

oh cool, so just a garden hose? lol thats pretty easy I guess. A new radiator should solve the fan problem too then?

With your 20 year old car, you probably do have blockage in the rad. Crap that breaks loose, rust, etc.

You could try a radiator cleaner, though I don't think they are all they promise to be. If they're strong enough to dissolve, or break up rust, they'll probably eat into the other parts of the rad, which are probably pretty thin by now, as well.

A good back flush, pushing water from the top to the bottom, and out, and from the bottom to the top,,and out, might help.

If you do that, flush the rest of the system, also, as it may help the heater. In fact, if the heater works, I think it is more likely the fan than the rad core. It should plug up more quickly than the rad would.

Check first that it is not that the fan circuitry that has failed. Hell of a note to put a couple hundred in repairs and find that a blown fuse was the culprit all along.

Cheers,

George