Typical coolant gripes

Have you tried just touching each radiator to see if they are about equally hot when the temperature gauge in the dash reads 200 deg F? Since the thermoswitch for the cooling fans is in the LH radiator a stuck thrermostat on that side could give you a symptom of:

LH radiator cool
RH radiator hot
dash temp gauge reads hot
cooling fans never come on

However, if both radiators are equally hot to the touch, but the cooling fans don't come on when the dash gauge reads 200 deg F = something electrical wrong.

So "radiators equally hot" or radiators not equally hot" should help you decide what to do next.

 

Check the white connectors as we'll for signs of burning / bad connection.

The only radiator bleeding I have ever done is to loosen the brass plug on top of the thermostat housing. You may need to do this two or three times but usually most or all the air is expelled on the first attempt. The Thermostats have a small hole in them to make sure that air cannot be trapped.

HTH


Phil

 

Yes, the SRI TR fusepanel modification relocates the fuses, relays, and main power connections for the water fans elsewhere (so the typical trouble place that Phil mentioned should already be out of the picture).

Connect the two wires of the water themoswitch in the bottom tank of the LH radiator together with the key "on" = water fans should run.

If the water fans run under these test conditions, but don't when the LH radiator is truly hot = water thermoswitch probably bad.

If the water fans don't run with the water thermoswitch wires connected together and key "on" = electrical problem somewhere else.

Not sure how the SRI mod affects the wiring going from the coolant thermoswitch to the fuse-relay panel, but this thread has some more information for how to do this test without having to get under the car if you still have a ZN (purple-black) wire at one end of the j horizontal white connector (post #2):

http://www.ferrarichat.com/forum/boxers-tr-m/524898-cool-now-but-getting-hot-stevem-please.html

 

Not sure (but that's why I prefer doing it at the j connector ).

 

Better off to unplug the fan switch on the left rad bottom and join the wires together. That'll test the entire circuit in an instant. No need to remove the splash shield.

 

to put the 2 wires at the thermoswitch together it needs not much work. if you have a lift you just see how easy it is, otherwise you may go under the car, but no need to remove anything than the 2 wires

 

I just replaced mine last week. Take it to the local parts store and tell them its from a Volkswagon Scirocco. That'll save you $50 - $250 depending on which F pimp you call.

 

size is 28 mm, an not so common size, but available, you need a long nut because of the connectors
but before you remove check if the radiator is getting warm, not that the thermostat is not working right

 

then you need a switch with lower temperature to switch off
my replaced switch has 28 mm from VW

 

there are sooooo many switches on the market with the same thread but with different temperatures
just now I´m in thailand and will be back end of july. then I will have a look and let you know. ( so if I would forget please remember me )
but I modified the complete system and put in on the right radiator also a switch only for the rigth fan then. as I remember the switch-on-temperature is between 85°C and 87°C and the switch-off is between 76°C and 78°C. but also I have other radiators inside ( 1 row more water pipes ) and those cool much more down than the original.
but I prefer a switch-off-temperature from under 78°C

 

Yeah that 4 seasons switch runs it a little warmer but it works fine. You just have to get used to that guage running a little higher. I found that the car runs very well, never over heats, but that needle rides just over the center line.

 

Better she runs a bit cooler vs hot. Switch it out

R