No Heat!

We have an old 2002 Passat GLX 4-Motion wagon. It has a lot of miles on it. But, it has been a super dependable car - for years I used it to commute to work (thirty-five minutes one way, forty-five minutes the other - traffic!) 

When I bought a newer commuter car the Passat took on a second life as a light-duty pickup. In that role, it has pulled cars out of ditches, pulled shrubs out of gardens, hauled fuel-oil,  furniture, concrete and made weekly runs to the dump packed with only the sort of refuse that a family with kids can produce. It's gone camping as the carry-all for the family's gear and even been camped in. It's carried kayaks, fishing gear, skis and children all over New England. I can remember one time, because my wife won't let me forget it, when she drove the Passat down to Sharon to rescue me when the '89 Golf I was driving back from Concord decided to suffer sudden oil pressure loss. It's been a hard life but that old Passat just keeps chugging along.

(I told you it has a lot of miles. Yes, and the obligaotry check engine light. We'll work on that later.)

Along the way, the heater core became clogged and, as no surprise, the car no longer blows hot air when called upon during the colder parts of the year in Vermont. There's an old joke about the seasons in Vermont. See, Vermont has four seasons: Winter, winter, winter and, for two weeks in August, not winter.

So...YOU NEED HEAT.

The heater core is essentially a second small radiator that sits behind the dashboard. Hot coolant from the vehicle's water-jacket flows through the heater core and heats the air that's pulled through it before entering the cabin via the HVAC vent system. Very basic really. 

In fact, a replacement costs less than a hundred bucks. No big deal, right? WRONG! Ripping the dash apart to replace it will cost you either a day of labor or around a grand if you have someone else do the labor.

Given the Passat's milage I just can't justify the investment. There is, however, another way. 

Let's call it better living through chemicals. 

See, what's clogging the heater core is all the same sorta sediments that gunk up all plumbing systems. Heater cores get blocked by crud and corrosion (mineral accretions from using tap water) or sometimes by the sludge created when improper coolant is used during top-off. The passages in the core are just a millimeter wide so it doesn't take much.

(Remove the plastic cowl over the rain tray and you'll find the heater core pipes next to the battery. The pipe to the right is the inlet and the left one is the outlet. A compressed airhose can be seen above ready to reverse blow-out the heater core. Don't be shy about using compressed air and hose water to flush the core. In fact, I ended up flushing it with both and flushed it out from each direction just to be sure.)

Sometimes, the core can be flushed with compressed air followed by water from a garden hose. If that doesn't work it's time to reach for the CLR - this is the same CLR that homeowners use for clogged drains. 

After flushing the core and blowing as much of the water out as possible with compressed air, I filled the core up with CLR and let it set for twenty minutes and then flushed it again with water for another twenty minutes before blowing it out a final time and refilling with coolant. When refilling, you have to remember to bleed the air out of the system. 

On the Passat, the highest point in the cooling system is the heater core and there is a bleeder hole on the outlet hose. You can use this hole to bleed the air out of the water jacket.

(The homemade set-up pictured above was utilized to great effect. Note the CLR ready for action. I used the whole bottle. Child labor provided by my 13-year-old son. Pay no attention to the derelict Jetta in the background. If you've followed this blog then you know that this old hot rod is all rotted out. Fear not, its parts are being salvaged for other projects. In this way the old white Jetta lives on.) 

Long story short, after all that work, it worked. The heat is back. And, best of all, the dash did not need to be ripped out. 

P.S. - While I was at it, I changed out the old, cabin air filter for the first time...ever.

(I don't think I need to tell you which one is the new one. Yay! All set for another six-hundred-thousand miles.)