Over recent weeks when I've moved the heater lever off its cold setting I've had 20 seconds of a "burning" smell, followed by massive misting of the windscreen which has taken ages and ages to clear.
Yesterday I even had steam coming out of the vents when I turned the heater on, 20 miles into my journey. This was followed shortly after by the red temperature light coming on. I pulled over, waited a few minutes for it to cool down then managed to get to work without any further problem.
Home time comes round so I check a cold engine and the coolant is way below minimum. I top it up and get home without a problem.
Anyway, I'm thinking this is far more likely to be a heater matrix issue than an actual coolant leak as there is absolutely no indication elsewhere of the latter. No obvious leaks anywhere, nothing under the car, temperature gauge absolutely rock solid on the first mark etc. etc.
However, there's clearly some moisture lurking somewhere and, with the screen misting so badly, I suspect a slight leak in the heater matrix somewhere. So my question is, is it ok to sort this with a juicy dose of sealant or is that just putting off the inevitable of changing the matrix? I wanted to avoid the drama of pulling the dash to pieces to sort that. What do you experts reckon?
