My barn find mk2 golf has a heating issue I need some advice on. INFO - mk2 1.8 automatic Syncro Tour 1988. Once the cars tempature is hot enough, the fan does not kick in! But does work when hooked up to the battery. It seems that the water pump does its job by pumping water/coolant into the resivoir, and most pipes do run the water inside of them fine, but it seems like the coolant/water is getting really hot and the engine and pipes feel scorching, fan doesn't kick in? I have changed a few thermostat switches and a housing and I still have the same problem. Could it be my radiator that is bust or could it be a sensor? I'm stuck here and need to get it sorted before the head gasket blows it's lid off Cheears!
unplug the thermoswitch on radiator, loop a wire between the red and red/white then red/black on the plug. fan should run slow then fast, if that works its the thermoswitch or radiator is blocked preventing coolant from circulating, or you're not letting it get hot enough to cut in. should trigger the fan around 3/4 on the gauge, then run till its just under half
Tried that, the fan kicks in so that works could be radiator will order one of those. How can I flush the crap out if there is a blockage?
Tbh I'd replace the rad as a matter of course, you'll never get all the crap out. But if you drain and refill the coolant system a few times before fitting the new rad, you'll probably get rid of most gunk elsewhere in the system. A new header tank and OEM blue cap would finish it off nicely.
make a judgement depending on the state of the coolant, if its full of all kinds of crud then as above id replace, also if the rad just looks shafted get another. its the same one as used in the 8v gti common as hell loads on ebay. as I say, make sure the engine is actually getting warm enough though
