Heating issues

[Explorer Buff]

As it has gotten colder I've noticed a new issue with my 2001 4.0L Explorer XLT.

It seems to warm up fine but with sudden and short bursts of cool air that blow out of the vents. Then it gets warm but then hte busts of cool air get more frequent, finally reaching the point where even on high on a non-AC position it is blowing cold (albeit not air conditioned) air through the vents on the hottest setting as well as the coolest setting. The temperature gauge is reading normal warmup progression.

So I'm thinking either thermostat (gasp) or heater core. Anyone have any suggestions?

Thanks!

 

[marragtop]

If the temperature guage isn't fluctuating a lot, then I doubt if it will be the Tstat. Once warmed up with heat on, check to see if the heater hoses are hot.

 

[Explorer Buff]

If the temperature guage isn't fluctuating a lot, then I doubt if it will be the Tstat. Once warmed up with heat on, check to see if the heater hoses are hot.

Yea the T-Gauge isn't fluctuating at all, it starts on cold, goes slowly up until it reaches around the middle of the C / H normal range and sits there, thats why I didn't think it was the Thermostat

But it does actually get warm which is why I didn't think it was the heater core.

I swear this thing is possessed!

 

[Explorer Buff]

If the temperature guage isn't fluctuating a lot, then I doubt if it will be the Tstat. Once warmed up with heat on, check to see if the heater hoses are hot.

Yea the heater hoses are still hot. Also it seems that when it goes into those cold spells it almost sounds like the blower is blowing extra hard. Would this be something with a Vacuum leak and if so how would I know for sure / fix it.

Thanks all!

 

[Explorer Buff]

Anyone have any ideas? Thanks!

 

[Squilax]

Do you get a clicking sound when you turn the temp selector to warmer settings? If yes - it may be the blend door - lots of posts on this subject right now.

If not then maybe this is your problem - the vent door to the dash vents may not be working properly - check out this photo to reference the Panel/Defrost Door vacuum motor:

http://www.explorerforum.com/forums/...1&postcount=10

There is an arm that attaches this motor to a lever on the door to open and close it for airflow through the dash.

Steve

 

[mishawaka]

Have you checked your coolant level? You might possibly have air bubbles in the system. Mine does that sometimes when I'm low on coolant, I need the bypass update kit.

 

[Explorer Buff]

Do you get a clicking sound when you turn the temp selector to warmer settings? If yes - it may be the blend door - lots of posts on this subject right now.

If not then maybe this is your problem - the vent door to the dash vents may not be working properly - check out this photo to reference the Panel/Defrost Door vacuum motor:

http://www.explorerforum.com/forums/...1&postcount=10

There is an arm that attaches this motor to a lever on the door to open and close it for airflow through the dash.

Steve

Link didn't work for me but I haven't noticed a clicking sound when I turn to the hotter settings (should it be coming from the blend door area behind the glovebox or where).

Coolant level is fine but I guess flushing it couldn't hurt anything.

 

[Squilax]

I'll try posting the link again - click here for the photo. You can scroll up to read the entire thread if you want.

In my case, there is a definite clicking sound coming from either the blend door actuator motor or the blend door itself. You can feel the clicking when you touch the plenum. I have to manually pull the blend door closed when I switch over to high temp.

I have my entire lower dash apart right now and am working on the next steps - either testing the actuator to make sure the gears are meshing or pulling out the blend door to make sure it's not broken. At least for now, I have heat coming through.

Good luck!

Steve

 

[Explorer Buff]

Thanks for the info Steve, I'll look into it.

If I still lived in Lancaster County (I moved to Delaware in August) we could work on them together! I used to go fishing at Holtwood Dam for years before they drained it last summer to look for that girl that went over.

Andrew

I'll try posting the link again - click here for the photo. You can scroll up to read the entire thread if you want.

In my case, there is a definite clicking sound coming from either the blend door actuator motor or the blend door itself. You can feel the clicking when you touch the plenum. I have to manually pull the blend door closed when I switch over to high temp.

I have my entire lower dash apart right now and am working on the next steps - either testing the actuator to make sure the gears are meshing or pulling out the blend door to make sure it's not broken. At least for now, I have heat coming through.

Good luck!

Steve

 

[Squilax]

Holtwood Dam - no kidding! That's less than 5 miles from my home!

 

[Explorer Buff]

Since there is no clicking at all coming from the blend door I highly doubt that is the problem.

I'm still leading towards Vacuum leak but I don't know if my guess is right.

Last bump, anyone else have any ideas? Next stop is the dreaded mechanic!:thumbdwn:

Thanks!

 

[Explorer Buff]

I know I said I wouldn't bump this again but I did notice something else.

When I shut it off, it will not blow warm again. Even when I let it sit for a few hours in the cold, it will not blow warm air even when it warms up. It only warms up properly after it has sat overnight. So thats another totally weird thing about it, does that give anyone anymore ideas?