A3 overheating

[tlmc]

My son has an A3 and it is overheating. Checking I can hear a hissing sound from the back of the engine. ON further investigation, the top rad hose is hot and the bottem hose cold. The fan doesn't seem toi cut in either. Any suggestions as I'm not familiar with Audi's

Thanks

TLMC

[slimbaldy]

Hi, haven't actually had this problem with any of my Audi's but it sounds like a sticky thermostat. You can take it out clean it up and if you want test it in a pan of hot water or if its a good few years old then wise to change it anyway, with a good flushing out of the coolant system..rust particles can build up and clog thermostats.

[tlmc]

thanks. Now for the stupid question, where do I find the thermostat on the audi? Had a look and it doesn't seem obvious. Also having problems locating the water pump. Found a picture of one on the internet. Looks like it's belt driven but the only pits on the belt on the side of the engine are the alternator, power steering pump and connector to bottom of engine. Just ordered a workshop manual but won't get that for a few days.

Thanks for your help

TLMC

[kite]

Water pump is driven by the cambelt.

[lee172]

i had the same sort of problem with mine a month ago. I changed the thermostat which was just behind the alternator on mine (on the block). In my case it was the waterpump which is cambelt drven so i had to get new cambelt and water pump.

[tlmc]

thanks for the info. That was what I'm worried about. Did you do it yourself and if so, is it a big job?

Thanks

TLMC

[lee172]

The cambelt is one of them things i would rather get done properly.. i paid 220 for water pump, timing belt and tensioner fitted so it wasnt as costly as i first thought. But i did find out a few things that might solve your problem when i had mine.

The lid for the water bottle, apparently sometimes these can cause over heating problems

The radiator could be blocked, do you have any leaks anywhere?

You can check to see if its pumping water by taking the little hose off from the water bottle when the car is running, if water is not flowing properly chances are it is the water pump.

One more thing, on my engine 1.8 20v you can feel the water pump if you take the thermostat out, its to the left. So if you do check your thermostat have a look in there at the water pump. Hope this helps..

[m33sta]

If it is the water pump, dont DONT DRIVE THE CAR! you run the risk of having to buy a new engine if that goes and not just a new pump.

[tlmc]

thanks for all the input. Cars at a garage at the moment but due to a queue of work he can't get around to it until next week hence looking at doing things myself ;). Will get it back while I'm waiting for it to be done and replace the thermostat to see if that fixes the problem. Will check the water pump at the same time but think the pump is working as if you leave the top of the the water system it starts to overflow!!

Again, may thanks

TLMC

[AZA]

Did you ever get to the bottom of this? I've got the exact same problem and have replaced the thermostat and waterpump but the fans still don't work!

Thanks

[T.sport]

AZA,yours might be a fan fault,do you have vag-com?If your near south Kent i have Vag-com?

[tlmc]

Ours was the water pump in the end. Replaced with a metal one and problem now gone away.

[steve4487]

Hi everyone.
I'm new to this forum and am looking for some help. I don't whether I'm in the right section but I've just bought an A3 3.2 and the only way to stop the rad fan working is to disconnect the red with white tracer wire from the fuse box otherwise the fan runs all the time. Has anyone come across this before and now the answer
Thnaks
Steve

[T.sport]

Have you tried turning off the climate control?

[kite]

could be a faulty coolant temp. switch.