[zdive65]

I've the read the common cooling suggestions, let me bring you up to date on this build: MKIV VR6 turbo, heater core bypassed due to leak.

I bought the car 6 months ago, ran well with the exception of a needed updated tune, last month it over heated, the fans stopped working. I read the forums, changed the t-stat twice, bypassed the fans and they worked, changed mechanical water pump, changed the axillary water pump, changed the radiator sensor, changed the sensor at the thermostat housing, replaced the radiator, changed the FCM, checked all fuses.

Started it and the temp got up to 190, still no fans, top hose hot, lower radiator hose cold. I squeezed the hose below the aux pump and herd it gurgle then released liquid. which makes me believe there's an obstruction in a line or its a electrical short.

Hopefully someones got the magic answer!

basically everything has been changed except the hoses.

 

[_FUBAR_]

Are you using G12 coolant mixed 50/50 with distilled water? Is the coolant system properly burped of all air. It's hard to really say what could be blocking the flow.

 

[zdive65]

New radiator with g-13, 50/50, manually burping lines, crack pipe hot, Tatar hot, aux water lines hot, lower rad line cold. I'll continue to burp lines

 

[Pssst...passed you]

T-stat stuck?

 

[zdive65]

Update: after burping, finally got all lines hot. Still no fans, buddy came over and we traced lines, problem I think is resolved, bad connection at lower radiator sensor. I cleaned ends and pressed it firmly in place. Fans now working

 

[Razzmire]

Update: after burping, finally got all lines hot. Still no fans, buddy came over and we traced lines, problem I think is resolved, bad connection at lower radiator sensor. I cleaned ends and pressed it firmly in place. Fans now working

those darn fan control modules!
i cleaned my connections and replaced the module on my oldder golf and it still wouldnt turn on the fans, so i must have been less fortunate and had a worse problem. nothing a little wire and a toggle switch couldnt solve.:-(