Heating and Cooling - Intro

Heating and cooling - part 1.

So, during one of my drives around town, I noticed a bit of water around my driving foot. Not to worry - it was raining, and I thought it was probably a minor rain-related leak. Upon further inspection when I got home, I realized this was not plain water, but actual engine coolant.

Engine coolant leaks inside the car are usually not a good thing.

You see, heater systems inside most cars work by circulating hot engine coolant inside a small radiator (a.k.a. heater core) inside the car itself. A fan blows air through it (heating the air), and then to the rest of the car. For the most part, this is a fairly straightforward thing to do, but after many years, heater cores will corrode and spring leaks. On occasion, the valve controlling the flow of hot coolant onto the core will also fail, also springing leaks. Plus, you have all these rubber hoses getting coolant to and from the heater core, and these tend to fail over time.

To address this, the only thing to do is to remove any leaky parts and replace and/or rebuild them.

The two most common failure points on GTVs such as mine are the heater core itself and the heater valve. The heater valve can be sourced fairly easily at Centerline and/or International Auto Parts. It costs about $40-$50, and replacing it is straightforward.

Dealing with the heater core is a bit more involved. First, removing it from the car involves removing the complete case around the heater core itself (which contains the blower fan and other related parts.) Once this is done, rebuilding the core requires specialized expertise, and about $150-$200 worth of repairs. Then there's the matter of putting it all together and making sure it all works.

Sigh...

On the plus side, now I know what Alfa my winter project would be.

I figured I'd address this problem in two parts:
1. bypass the heater system. This is very straight forward - one bypasses the heater system from the cooling circuit. This allows me to drive the car, but alas, the heater becomes useless.

2. repair the heater system itself. Basically, disassemble the whole thing, figure out what's broken and repair it. While at it, I will replace the associated rubber hoses and any wiring that seems worn or about to fail.

Over the next few posts, I'll describe my adventures doing this. I suspect this will take a few months, as the holidays are here and my free time will be somewhat limited. But if you are curious about this kind of work, here is an excellent Alfa BB thread explaining this whole repair:

http://www.alfabb.com/bb/forums/car-restoration/3922-heater-box-rebuild.html


Next: Heating and cooling - bypassing the heater.