HI all, first post, looking for some pointers, but new to us 6n2 GTi. The issue is: Bought it as a car that had suffered an overheat a few months ago, we inherited a car with a damaged header tank (looks to have been butchered) and very little coolant and the cap secuerly stuck to the tank, apparently the car was left standing for 30mins ticking over, no fan kicking in meant it boiled over. So, the fan didn't run but does now (new fan), new header tank and cap fitted, flushed the system best we could. Symptoms now are Refill the cooling system via the header tank, run the car up to temp, top hose getting hot, heater blowing hot, bottom hose still cold/barely warm. Can feel pressure in the hoses, and the return feed is pumping through into the header. After about 15mins running at approx 2k the coolant starts to boil in the header tank and starts to escape via the tanks outlet point. Bottom hose still not hot but coolant warning light comes on. WE switch off the engine. The cars history shows it had a new VAG thermostat in Sept 2018, but not the housing. Not fitted by VW but by a local garage. So we'll pull the stat out and re-run the car without to see if this resolves the issue of the lower hose. Engine runs nice, no mayo, oil is clear. So we believe the stat isn't opening for whatever reason or is stuck shut/broken as such its boiling up. I can't add any more coolant in either and we're running it with the cap on now as coolant was just spurting out with it off. Could the car overheating like it did a few months ago damage the stat? Would it have been better for them to have replaced the stat and the housing at the same time, if so then thats what we'll do again and obviously we're best off using genuine vw parts, or could we just have a major airlock, if so so how does that get shifted? Any pointers gratefully received.
have a look at the thermostat flange, there is a plastic 'bridge' across it that the thermostat pushes against to open properly. flange is part number 032121121J, still available at VW for 16.84+VAT. as for stat itself, chuck it in a pot of boiling water then make sure the pin moves. part number is 032121110C, 17.07+VAT there are 2 part numbers for the flange seal, depending on age of the car. if you can post the chassis number up I can confirm which it is
thank you, it's coming out later today so will have a look and test the stat, so this bridge, now that make sense looking at the various pictures online. 6NZ1Y289329
thank you, I'll order this later this pm Edit, now ordered via TPS near me, oddly enough the local vw parts store was quoting a week on order, but the TPS store dealing with genuine parts will have this for me tomorrow pm!
an update, took the stat out, its ruined! Bridged failed and stat has fallen apart! Feel like we can see some light....
runs lovely, and the new fan even comes on so that's the main issue sorted, thanks for the part numbers we now have genuine parts fitted
