Heat at idle

[bonbon]

Has anyone observed that the heat from the hot air blower when idling (eg red light) is not boiling as when driving?
I know my valve is clean. If it's not like that for all - the only thing I suspect is a partially blocked core.
Any insights?

 

[bonbon]

finally a bit of winter here

 

[andyglym]

May need bleeding, could be an air lock.

 

[Ianmc]

Assume you have aircon? Is the blower working on all 4 speeds?

 

[bonbon]

Fan is working fine on all 4 speeds.

 

[Ianmc]

Andy may well be right. That said, I have found it difficult to bleed the cooling system and when not fully done the heater doesn't provide hot air at all: when on the move or otherwise. Has a full flush been done in recent times, recommended to be done every 3/4 years?

 

[andyglym]

These cars can be a PITA to bleed, Jack up the front and try to get rid of any air pockets.

 

[bonbon]

The car has been bled on a 30 degree slope after a new rad was installed a month ago - so doubt its and air pocket.
I suspect a partially clogged heater core - if what I am seeing is abnormal.

 

[Antm72]

Mine did this randomly on one outing never had any issues but only got heat sat still. The temp dropped along with the gauge temp on the move. The stat had failed swapped it out and it restored heat.

 

[bonbon]

My bet is that what I'm describing is not unusual. Let me know if anyone stops at a red light and compares.

 

[t-tony]

If you're convinced that the heater matrix is partially blocked then add some cooling system flush and the back flush the the heater in the opposite direction of normal flow.

Tony.