92 VW GTI heater core bypass operation

I was amused to read in a recent post on rec.autos.makers.vw.watercooled the comment, "One of the things I liked about the many VWs I owned and worked on for friends is that they always broke in the same ways." So true it is! When my headlights went out on my current Golf, I knew just where to stick a piece of paper to temporarily revive them. When steam began drafting out of the air vents, I remembered how I duct-taped over them in my previous Golf to "solve" the same problem. This time it's just a mental note: heater core's gone busted.

The heater core is a "mini-radiator" lodged somewhere in the dash. Engine coolant circulates through it, and ventilation air is directed over it when you turn on the heater. As far as I know every car has one, and a little googling shows that they all fail eventually. On the MkII VW, replacing it is particularly onerous, since it must be the first thing they install when building the car. And it always fails. I looked at some ads for the same year/model of my car on VWvortex. The first one said, "its got 166 some thousand miles on it, it runs good the heater core is bypassed." The next one, "heater core done by [previous owner]." The next, "Runs and drives awesome. Brand new heater core."

The cheap way to "fix" the heater core is to bypass it, to re-route the plumbing so that the coolant doesn't go through it anymore. To do so, I pulled the coolant hoses off of the heater core in the engine compartment and then went to Denault's to find some hardware with which to shunt them. I found a selection of copper pipe fittings, but alas, none making a 180 degree "u turn". This, of course, turned into an excuse to learn to solder copper pipe. I grabbed two 90-degree pieces and had the hardware man cut me three 1.5 inch lenghs of 3/4" diameter copper pipe. (He sold them to me for 99 cents each.) I also bought a soldering kit, which included a can of solder flux, a brush with which to apply it, some solder, etc.

At home with great excitement I fired up a propane torch I found in my brother's room and set about the soldering job. It went excellently. Minutes later I had the thing installed in my car. Problem "solved." As pictured above. Maybe this weekend I'll try to extract the old heater core and fix it for real.

The folks on alt.autos.toyota don't seem to have nearly as much to talk about.