UK-POLOS.NET - THE VW Polo Forum

Hi all,

I've been lurking for a while on the forum and reading a few bits and now comes my first post! wish it was under better circumstances though! once i get this sorted i'll get a proper introduction and car thread going.

My problem is as follows:

The car overheated on the M25 the other week, suddenley and without warning. I have removed the thermostat and replaced as i've heard its a common problem. i tested the new one before fitting and it worked fine. i have replaced the thrmostat but still have the same problem.

I've read the few posts on here regarding over heating so went about testing the fan switch and thermal switch. they all appear fine. its still appears that the thermostat is not releasing the coolant to the raditaor when it gets up to temperature.

I had a fiddle with the switches and now for some reason my fan stays on rotating slowly (under power) when the engine is off which makes me think i have tripped a relay somewhere. I disconnected the fan power but the battery has now run flat so its drawing power from somewhere?!

my question is....... inside the thermostat housing does the small pin from the thermostat push against the housing in order to open? or does it just sit inside the small hole for placement? the only reason i ask is that i checked the housing and it appears that the inside has broken as it looks like theres a small piece missing but i have been unable to find what it should look like originally! the thermostat stays in place but i have a feeling the samll pin of the thermostat is going through the guide hole in the housing and not allowing it to open.

any help would be greatly appreciated as i'm forced to walk to work at the moment!!! not the way forward! haha

cheers

Swiss.

When the thermostat housing breaks, the pin from the thermostat has nothing to push against (and subsequently open and allow coolant to pass) therefore it sounds like your housing is broken.

It could also be a failing waterpump if the thermostat housing isnt the culprit.

hi,

I've got hold of a new housing from VW as the housing was knackered. when pulled it all off again and the pin from the new thermostat was wedged in the housing thus breaking another thermostat and confirming the one i had was finished!

Ive got a new thermostat and the housing and also a new radiator fan switch as the one on the car had seen better days. i've gotta put the new thermostat and housing on tomorrow then i'll see whether that sorts the problem.

Since fiddling though, my battery now runs flat in about a day for no apparent reason. My mate who thought he knew what he was doing was sticking wires into plugs and i've got a feeling he's blown something somewhere. Is there any simple way of checking what could be drawing the power from the battery as it was fine before all this started happening?!?!