AAAAARRRRRRGGGGGHHHHH! Running Hot!

[filthy]

Hey guys, my 8v GTI has been running hot lately and i can't find the cause and i'm going slightly mad now....

Basically, its never actually overheated, but it has started to run hot...in town driving it sits at 100 deg, at idle it goes to 110 deg with the fan on constantly, the fan seems to hold it there, at motorway speeds, its at 90 deg (where it should be!)

I've had the car 3 years and its always sat at 90 deg, never over

So far its had

New thermostat -3 of them!
New fan switch
New temp sensor
New rad cap
New waterpump
New radiator
Done a sniffer test- no gas in the coolant, no white smoke, no mayo, no loss of power

I'm properly vexed by this one

Has anyone got any ideas?

 

Edit- forgot to mention, the heaters are hot and the system is bled-I'm an expert at that now!

[Christo77]

Hi there..
The engine itself is definately overheating? as oposed to a faulty gauge or sensor..?
I guess it is if your getting very hot air through your heater vents..

Have you done anything to the ignition timing recently?  something changed there maybe..

Or is your radiator blocked or restricted?.. Maybe the thermostat has failed?..although depends if it's stuck open or closed..i'm not sure which, or even if this could be the problem really..

Another thing would be an airlock in the cooling system..although sounds like your on top of that side of things,
Maybe even the coolant pump...

Sorry to just throw ideas at you rather than a definative answer..  let us know if you make any progress

[Christo77]

Hi.. just re read your post..seems you've tackled most of the things i've mentioned anyway.. sorry   

Apart from the overheating..is the engine running ok?  no misfires or rough running, smoke from exhauset etc..