issue with heater

[OgreSmash]

ok so heater works great when I'm driving. but as soon as I come to a stop it blows cold. start driving blows warm etc etc. any ideas?

 

[sperold]

Low coolant level.
When it cools off, fill the rad directly, not in the overflow jug.

 

[OgreSmash]

last I checked the coolant level was fine

 

[limited02]

last I checked the coolant level was fine

Have you replaced the thermostat? If so, might need to burp the system.

 

[SHOdded]

Sounds like air in the system.

 

[Jeff2017]

Could it be that the water pump isn't moving the coolant when idling. Busted impellor(s)?

 

[OgreSmash]

I think if that was the case the car would over heat right? which it doesn't do

 

[Jeff2017]

Well, I had a 2008 Volvo V70 that had a water pump that was shot. It was so worn out that the auxiliary drive belt was slipping due to the play in the shaft of the water pump. It was not over heating or leaking antifreeze. But the AC would intermittently fail to blow cold air because of the slipping auxiliary belt which caused the compressor to not turn fast enough. It was just a thought. How many miles are on your car?

 

[OgreSmash]

almost 103k

 

[Jeff2017]

If you have one of those OBDII scanners that has smart phone blue tooth connectivity, I would hook it up and see what your engine temp is when this happens. The digital temp gauge isn't very high resolution so if it is running 20 degrees above or below normal it will not be noticeable via the gauge. Mine shows no difference from 190 to 212.

 

[OgreSmash]

mine has the needle gauge

 

[OgreSmash]

I don't have an obd scanner yet. to many bills adding up and not making enough $ to afford one right now

 

[Ahrmadillo]

if everything is okay then you probably have a blockage in the heater core. if you cant figure it out see how much a coolant flush and cleaner costs and have it done by a garage with the machine they use.

 

[Jeff2017]

mine has the needle gauge

So does my Volvo. I think it is designed to stay top dead center unless the engine gets into the danger zone. Not sure what the granularity is with the Ford analogue temp gauge.

 

[OgreSmash]

well last night and this morning it seemed to work better. maybe just a hiccup in the system

 

[SilverSH0]

last I checked the coolant level was fine

Fill it up until it's as full as possible or maybe a little more. I've seen several threads with this same problem with the coolant between the min/max lines and it was fixed by topping off the coolant.

 

[ridered74]

Mine did that a year or two ago. Put more coolant in and has been fine ever since. Had to go above the full line.