Author Topic: 2 heater cores in 15 months? (Read 4293 times)

Patrick · « **on:** March 19, 2006, 04:07:53 pm »

My OTHER 92 jetta got some work this weekend too. 2nd heater core in 15 months, jobber supplied "Valeo" parts. No obvious damage due to parts rubbing, etc. leaking inside the fins. What gives?

wyldman · « **Reply #1 on:** March 19, 2006, 08:03:10 pm »

Improper handling and installation can easily damage a core.It may have been twisted or damaged before you got it.

There are usually two things that will take out a heater core that quick.Overpressurization,and electrolysis.Too much pressure can be caused by a cap that fails to release excess pressure.A head gasket starting to go can do it as well.Electrolysis actuallys eats a pinhole in the core due to stray voltage in the cooling system.It can be easily checked with a voltmeter.Dunk one probe into the coolant,and one to the negative battery cable.Do this with the engine running.If you read more that .2 volts,you have a problem.

Patrick · « **Reply #2 on:** March 20, 2006, 03:09:50 am »

Thanks, I'll look for stray voltage. Like I said, there was no obvious damage (external) to the core I pulled out. Bad ground somewhere maybe?

What a PITA job! Took most of the day (92 Jetta with air)

wyldman · « **Reply #3 on:** March 20, 2006, 06:34:01 am »

It could be a bad ground.Verify that the stray voltage is your problem first,then we can track down what's causing it.

BlackTieTD · « **Reply #4 on:** March 20, 2006, 06:36:57 am »

just throwing this out there....

VW recognized a heater core problem somewhere along the line and while doing recalls had their techs install some sort of valve to restrict the pressure that the heater core would see in the case of over pressurization. you could look into that and take the same precautionary measures.