Khare's problem thread - Engine mount and screeching noise page 15. EUROPE TRIP!

[Khare]

Rad is getting hot all over, including the thermoswitch area. The stat is opening shortly after temp hits 90C and it seems to be opening fully as the bottom pipe is getting very hot.

That narrows the search down to the thermoswitch....Right?

[Horney]

Did it work OK before the engine swap?

Nick

[Khare]

Did it work OK before the engine swap?

Nick

Well I'm not sure dude, on the trip down the mate that drove it down didn't really understand about cars so he didn't mention anything about temp. When I took it for quick blasts around the local roads while waiting for the swap it never got to full temp so I can't really say. However....I just remembered that the rad is from the donor car, it's a VR6 radiator, so it could well be the switch is broke on it as I don't know the history of the car. I know for sure my old rad the switch was working perfectly well.
I'm about to order a new switch from AVS and I'll see how that goes when fitted.

[Paul86S2]

If the fan is working properly, your stat appears to be working properly and water appears to be flowing around the system then that should only leave your fan switch.
As it seems it was an unknown one that will hopefully resolve your problem.

Paul

[whiter_than_white]

do you not have your old rad to take the switch off?? even just for testing purposes if you want to fit a new one??

[Khare]

Yeah it leaves the switch as the culprit so I've now ordered a new one, should be here on Thursday/Friday hopefully.

do you not have your old rad to take the switch off?? even just for testing purposes if you want to fit a new one??

Left the 8v rad at the IOW, so I can't test the switch.

[rubjonny]

110 on the gauge is NOT overheating, its to be expected the temp will creep up if the car is not moving. the fan should cut in around 3/4 on the gauge and keeps going till temp gets to around 1/2. the blocked pipe is definitly NOT normal though, so fix that. If the fan doesnt come on when gauge gets to 3/4, then it could be the fan switch.  Have you tried bridging the pins on the fan switch plug? bridge the red wire to each of the other 2 pins in turn, and fan should run slow & fast.

if the warning light on the dash goes off, that means either car is overheating or coolant level is low.

[Khare]

RJ, I remember on the 8v engine though the fan would come on when stationary for a while, but the temp would ALWAYS sit bang on 90. It would never be under, or over. I've bridged the fan, works at both speeds.

That blocked pipe does bug me though...Why would VW put a bung on it? Guessing it's common as Paul has it on his one as well...

[rubjonny]

my 16v pipe doesn't have this, any chance of a piccy? this pipe should never be blocked otherwise the system will never self-bleed properly

[Khare]

No pic as I couldn't get the camera to the right angle. But the bung used seems to be factory made, it's moulded to the pipe by the looks of things. The only way of making a hole would be by sticking a hot piece of metal carefully down the small tube and melting the plastic until it pokes though...