Possible Cooling Fan Fault

[nveeate 78]

Hi,

 

Having a bit of a problem with the cooling on my 1.9 GTI - on the motorway at the weekend it started getting hot and the red temp light came on. The gauge didnt go any further towards the red, and the warning light went off again fairly quickly (though then came back on!). I pulled over and let it cool down....was quite surprised as I would've thought the air flow would keep the temp down at motorway speeds.

 

Anyway, I've had a look on the forum and have a few things to check...lots of posts on this! However, one thing I did do was bridge the contacts on the brown 3-pin tester plug. With this I could only get a fan to come on with one of the pins (live plus central pin). I'm guessing that this could mean that my low speed fan isnt coming on - please could anyone advise how to check this (or give an alternative diagnosis!). I'm still learning my way round the engine, so please bear with me!

 

Cheers

[Anthony 1,003]

You've got another problem than the fan if it's overheating at motorway speed. Thermostat would be my guess.

 

If the fan works on high speed but not low speed even from the test plug then it's probably a fault with the resistor (or it's not plugged in!)

[nveeate 78]

Ok, thanks. I'll do a search for how to locate and test the resistor!

 

I need to have a proper look at the weekend when I have some time, but the radiator didnt feel uniformly warm, so I'm wondering if it might be blocked - perhaps this would tie in with your thermostat guess?

[Tom Fenton 1,548]

As Anthony says the stat can give this problem and I have experienced it before. But if the rad was not uniformly hot then this could also be furred up internally. I have had this on a customers car, the rad looked perfect from the outside and did not leak but just did not keep the thing cool. New rad sorted the problem, the pattern ones on ebay at £40 are perfectly fine.

[nveeate 78]

Ok, thanks both.