2005 XJR. now that it has gotten cooler, when the heater is on there is a coolant smell from the vents. If I turn climate control off, it goes away. Sounds like a leak in the heater, but what is the likely scenario? I'm also getting a ticking or crackling sound behind the center vents it comes and goes, but it often continues after the engine is off. I have yet to find wet carpets, I have put Dex-Cool approved dye in the system, so far the black light shows nothing under hood or interior.

 

There is no cut-off valve on the heater circuit, coolant circulates all the time, heating on or off; a flap closes off the matrix when no heat is needed. It does sound like you may have to examine the heater core and its connection pipes. This is actually fairly easy to do, (yes, really !!). You will need to remove the glove box assembly, then the heater fan and control model, after which you will be able to see the end of the matrix and its connecting pipes. It is NOT necessary to dismantle the whole dash assembly.

 

Thank you thank you thank you, and special mention to the engineer who made that accessible. I have taken a dash out one on an F 150, it was a very intense job, and it was never right after, you always seem to break a fastener mount or something. I'll pull the obstructions and check it out time and weather permitting. for now, it isn't that bad the heated seats are enough to just leave it off, up until I need defrosters. Here is hoping it is an o-ring or some trivial thing. I looked at the heater hoses under the hood, they look like they would have an o ring. Safe to assume the ones inside the care are the same?