heater issues, new guy

ive had my xj for over a year now, and ive just noticed as its just gotten down under -20 celcius here, is there any real reason why my heater would literally put out no heat at all, just cold air, when my engine is runnign warm?

Plugged heater core? Take the lines off the core and flush it out.

Heres the heater core flush write up. makes a huge diference.You will be surprised how much Sh** comes out
http://www.olypen.com/craigh/heater.htm

having an 89 you've got the closed cooling system. I'd venture a guess that it's either plugged, or you've got air in the system yet.
Do a complete flush, and make sure you purge the air out of the system.

Raise the back of the XJ
pull temp sender in the back of the head, it's located drivers side all the way back, looks like a little top hat. Do this COLD!
pour coolant into the bottle until it comes out of the temp sender hole.
Replace temp sender, fill coolant bottle.
Run motor until upper rad hose is warm, replace coolant as needed in the bottle.

I believe the older Renix's have some kind of plastic valve under the hood on the heater lines that is vac operated. Check that, as well.

TacticalFats said:

I believe the older Renix's have some kind of plastic valve under the hood on the heater lines that is vac operated. Check that, as well.

Click to expand...

yes they do, on one of the tees to the core.

thanks guys, sorry i didnt reply sooner my computer crashed... cursed lappy. either way thanks alot, ill give it a whirl this weekend if i get time