I am deleting the heater matrix in my Mk1 Scirocco that is running a 9a 16v. There is a pipe going from the side of the cylinder head to the heater matrix and then the another pipe from the matrix connects to a metal pipe that looks like it goes down to the water pump. This metal pipe also has a branch off it to the bottom of the expansion tank. I would like to preserve the expansion tank but remove the rest of the pipe. Does anyone know the best way to do this? Can I remove the metal pipe and cap it at the pump and then connect the expansion to the side of the head? Any help appreciated. Adam
the pipe returns to the waterpump so ideally you would run from the side to there as well as the tank. that being said some just blank the side flange altogether without issue, but VW added a bypass hose from side flange to metal pipe to allow coolant to circulate even when heater valve is off so personally I'm not so sure of the long term safety doing that... you could cap the end of the metal pipe with a rubber bung, vw do this from the factory on some engine/car combos
I had noticed some racers block off the front head outlet and run the side one back to the rad, apparently it gives better head cooling. Have you seen that setup before?
yeah that does make sense since the inlet is on the right side and head outlet on the left so will force coolant to flow right across the head I guess, with the side outlet blocked I'd be worried you would get a hot spot there... you can get a block off plate for the 16v head its from an audi v8, 077 103 093. had a quick look doesnt seem to be avaiulable, but tbh its a flat plate with 3 holes in so no biggy. gasket for it is 077103095A again doesnt seem easy to get but gasket paper exists so...
Thanks that’s great info. Can’t find anything listed, looks like nla so might have to make the plate and gasket. Do you know where the pipe on the bottom of the expansion connects to, does that just go back to the water pump?
the pipe on the coolant tank goes to the metal return pipe somewhere, which goes back to the waterpump as you say. if oyu want to keep the tank but get rid of the metal pipe entirely you can just plumb the tank to the waterpump direct