Blowing heater cores

[commuter boy]

I'm kind of stumped on this one.  I replaced a blown heater core in my 93 AAZ Passat two years ago, and it just went again.

No overheating issues, just a bit of moisture out of the vents then an hour later wet feet.

Would there be something causing this I should look at, or have I just had some bad luck?

[burn_your_money]

what type of coolant do you run?

[Vincent Waldon]

No overheating issues, just a bit of moisture out of the vents then an hour later wet feet.

Is it coolant for sure, or condensation from air conditioning not draining ??  On the MK3s there's a drain for the heater core/evaporator assembly that likes to clog and then pee at your feet.  Passats might have the same thing ?

Here's some pictures... you might be lucky ??

http://forums.vwvortex.com/zerothread?id=2631910

[jtanguay]

so is the heater core blowing due to the clogged evaporator drain?

[Quantum TD]

so is the heater core blowing due to the clogged evaporator drain?

Could be if the moisture was rusting out the bottom of the core. I've seen this on old MK 1 cars. the drain tube on the early cars was tiny and prone to clog. If the box was well-sealed, then you'd get almost 3-8 inches on water on the bottom of the box. This will surely rust out the ac evaporator and/or the heater core.

[Vincent Waldon]

so is the heater core blowing due to the clogged evaporator drain?

I wasn't thinking this so much as the clogged evap drain might be another cause of wet feet.

[commuter boy]

Nope, definitely coolant.  I run the Prestone LowTox propylene glycol stuff, haven't had a problem with it in any of the half dozen or so vehicles it's been in.

AC hasn't worked in years, so I doubt it's that.

[squirrl22]

I've switched all my "keeper" vechicles to waterless coolant.
http://www.evanscooling.com/
So far, it has saved two of my engines from overheating-  sure, this stuff is EXPENSIVE, but I figure spending $100 on cooant  has saved me over $800 in repairs.  
Because there is no water, there is no corrosion, there is no pressure build up in your cooling system.  You can also run higher temperatures safely, which can increase your MPG.