1999 A3 1.8T - Overheating

[Alex Buckland]

Hi,

I've got a 1999 1.8T A3, which up until a couple of days ago was running fine without any issues.

Took it round Thruxton on Monday, and it started to overheat a little way in - upon inspecting it further, the fans on the radiator refused to start at all.

Started to strip the fans out today, and noticed some of the wiring was pulled quite tense.

Started the car up, and turned on the AC and to my surprise both fans on the radiator started turning. I then turned off the AC and both fans stopped.

After I let the engine get up to temperature, I was expecting the larger fan to start up again (VCDS was showing 99 - 103C), but this didn't happen.

If I turn the AC on, both fans immediately start.

I'm quite confused here, as I was under the impression the smaller fan only ran with the AC, and the larger fan ran when the engine reached 90 / 95 C.

Any ideas what's the best thing to check next?

 

[ben4866]

Have you checked the fuses on top of the battery? The fuse holder tends to get hot and melt and cause issues with fans.

 

[Erikn89nl]

Mine does the same thing, keep us posted on your progress

 

[joesurf]

ditto for the fuse check - your fan works, just not when it should, fuses or maybe temp sensor/sender!?
BTW! Just found out I made 217 BHP with heaps of torque on a '99 AJQ today thanks to stu at tuning labstage 1 stillcant wait to collect.

 

[Alex Buckland]

Didn't manage to get the fans sorted ... they're still intermittent.

Think I'll replace the relay eventually, but as for the overheating - the water pump had exploded into multiple pieces!