Why does my heater core keep failing?

November 6, 2008 1:01 PM

The heater core in my 2001 Ford Taurus has just failed for the third time in less than 18 months. The car has about 90K miles on it. What could be causing these repeated failures?

Servicing has always been done at a dealer but not always the same dealer. We assumed the first failure was normal wear and tear. The second failure happened on a trip so we had the repairs done at a different dealership in another state. Because it occurred more that 12K miles after the first repair, it was not covered by our warranty. Four months after it was last replaced, the heater core has failed again. The car is at a third dealer now because my son has it at college. The warranty on the last repair should cover the work but I want to understand what could be leading to this reoccurring failure.

posted by maurice to technology (6 comments total)

My guess would be some kind of galvanic corrosion, possibly from something electrical that is failing and grounding onto the engine block or coolant. This might cause any metal immersed in the coolant to corrode at a rate faster than it was designed to. I'd have the dealership check the electrical system.
posted by kuujjuarapik at 1:49 PM on November 6, 2008

Are you completely sure of the nature of the repairs that were performed?

Tauruses (Taurii?) are notorious for heater core problems. The heater cores are so difficult to replace that there's a standing joke that goes along the lines of: Q. "How do you manufacture a Taurus? A. "You start with a heater core and bolt things onto it."

Unscrupulous dealerships will run the system full of some stop leak crap product, which will get you out the door and hopefully somewhere far away before it starts to leak again. It's a huge pain in the ass to properly repair one of these, involving removing/loosening the entire dashboard, and so they actually almost never get repaired properly.
posted by pjern at 4:00 PM on November 6, 2008 [1 favorite]

there is a steel tube between the heater core and the radiator that should be replaced, along with your thermostat and water pump

as kuujjuarapik guessed, it does cause galvanic corrosion when it reacts with the aluminum heater core and fouls up your water pump.

this is yet another issue that Ford is well aware off, but choose to play dumb and stick it to their customers instead. No wonder they are dying....
posted by Mr_Chips at 4:48 PM on November 6, 2008 [1 favorite]

Thanks for the comments so far. I guess I can't say I'm completely sure of the repairs but if there was any shady business going on I would say the second repair job, which failed after four months, would be the more likely candidate. That was done out of state while my wife was visiting family. The first repair was done at the dealer where we bought the car and where we'd had most of the work done. They could have been pulling a fast one on us but I think it's less likely.
posted by maurice at 4:59 PM on November 6, 2008

Sell it. Really. When a car gets this kind of repeat issue you need to ditch it.
posted by caddis at 8:05 PM on November 6, 2008

I ended up getting the heater core replaced under warranty. The mechanic hinted that the previous work was shoddy although he didn't come right out and say that explicitly.
posted by maurice at 7:27 AM on December 8, 2008