1998 mazda millenia s problem: heater/defroster works great when car is moving (good heat temp) but when its sitting and idleing, it starts blowing cold or colder air. Help
Do you
have the same problem?
Yes
No
Sunday, December 5th, 2010 AT 2:46 PM
1 Reply
WRENCHTECH
MECHANIC
20,757 POSTS
That's probably a partially restricted heater core. You can try running some flush chemical through it and then disconnecting the heater hoses and flushing the core with garden hose pressure but that may not work and you ultimately may have to replace the core.