No heat

[91 ECO]

I have a 91 Jetta ECO with 287K on the clock.  This car has been in my family for 10 years and the heat has always worked great.  This thing would run you out of the car inside of 5 minutes.  Last summer I converted the a/c to r-134 and then tried to run down an overheating problem (never ran hot, just hotter than i want).  Ended up replacing the thermostat with a lower temp t-stat, but the problem was a clogged radiator (replaced).  Now the will blow luke warm air for a while, but even that goes cold after a 20 minute trip on the highway.

Any ideas?  I'm about to put a standard t-stat back in the car, but I'm wondering if I have other problems.

Thanks,

Mark

[mainer]

what is the out side temp? what temp t-stat are you running?
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grand daddy purple

[leprechan]

I had this problem about a month after replaceing my heater core.  I ended up pulling the hoses off that are connected to it and then running water through it in both directions until I was sure there was no flow problem.  To me it seemed like I had an airlock in the heater core, but yours may be in the proccess of getting clogged up.  If you haven't replaced the heater core, chances are it could be plugged.  I learned sometime ago that they had a recall on the cores put in A2's.  If you have to replace it prepare to learn how the dash is put together.  Its a real learning experience if you've never take it apart before.  Good Luck

Nick

[91 ECO]

I'm in North Carolina and the temps lately have been 50s during the day and 30s at night.  I believe the t-stat is 160* and it's not letting the engine get hot enough.  Even so, you would think that it would still blow hot air.  I'm hoping it's not the heater core.  That process sounds beyond my experience and patience level.

[leprechan]

There is a quick way to check your heater core.  Go for a quick drive until your engine gets to operating temp.  Feel both the hoses that go into your heater core.  If one hose is hot but the other is barely warm then you're not getting proper flow through your heater core.  If its not your heater core, you must have problems elsewhere.  Is your car still overheating?  I had a water pump that acted strange for a while.  It would be fine until about 15 minutes after it reached operating temperature.  It turns out that the impeller is pressed on and when the water heated up enough the impeller got loose and sort of floated around on the shaft lazily spinning and not regulating flow.  I found out that the pump was bad about a week after I replaced the timing belt, so off that comes again just to replace a rotten water pump.  Anyway good luck with that and hopefully its only airlock.

Nick

[91 ECO]

Replaced the t-stat last weekend with a 180* (82*C).  Heat seems to be better, but we have a warm spell going here in North Carolina.  Guess I will wait for the cold weather to return.  Thanks for the help.