Heater blowing warm air

[kerstingm]

I posted this a while back and I was told that it could be the heater core or the blending door. Now that it's cooling down and we have been using the heater more I have noticed that the heater will go from luke warm air to hot. This is with the temp set al the way to hot, but if I move the switch from hot to cool and back to hot then the air goes back to being luke warm. My question is could this be the thermostat or is it sounding more like the blending door.

 

[yammerslammer]

Sounds like the blending door, but I would go ahead and replace the thermostat first.....just in case.

 

[gazbold]

Time for a flush ?

Sounds like the blending door, but I would go ahead and replace the thermostat first.....just in case.

Hi

It could well be one of those problems, but have you considered doing a reverse flush on your coolant system ? Its a job as disliked as changing out the Expys spark plugs but equally worth the effort.

I've experienced similar problems and after changing out a perfectly good 'stat to no avail, I flushed out the system. On my mechanics' advice I paid particular attention to isolating the front and rear heater cores to give them a good blowout individually (clamp off relevant hoses to localize flush circulation). I flushed out a large amount of what I can only describe as small blobs of very soft clay from the system. Looked just like sh#t in my coolant !
That and rust flakes that never seemed to end (I was filling buckets from the exit point to see when it truly ran clean/clear).
After a couple of hours of creative plumbing I re-filled and ran. Then test and top-ups etc. Boy that heat was crankin' and consistently so. No more complaints from the wife about little heat !

Hope this helps !

Now onto the rest of that darned honeydo list.

 

[joedmti]

Blend Door

That feels like a blend door issue.

Check out heatertreater.net and eyeball their Expy videos., they will show you how to quickly get to the blend door thru ur glove box.

With a dremel tool, and 15 minutes time, you can access and eyeball the blend door and see if its fuctioning properly