No heat at idle only on high RPM

Tiny
EVILPUPPETMASTER
  • MEMBER
  • 2005 FORD FREESTYLE
  • 130,000 MILES
Hi,

I have the vehicle listed above it is the SEL model. It has 3.0 V^ Duratec engine.

My problem is that car does not blow any heat at idle. Heat starts blowing only at higher rpm's, I have changed coolant, thermostat, coolant reservoir and cap as well as flushed heater core which had no rust in it. The car does not overheat at all. I did notice however that after cooling down I still have pressure in the coolant reservoir when opening the cap (it should not happen on the cold engine).

I was told that it could be ether cracked head or head gasket allowing cylinder pressure to get into the cooling system. There is no smoke out of the tail pipe and oil looks good. Another possibility is water pump impeller, but I really do not think so.

I need suggestions to try out and or help with illustrations to replace head gasket.

Thanks!
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Friday, February 10th, 2012 AT 8:55 PM

12 Replies

Tiny
KEN
  • ADMIN
Hello,

This sounds like a typical problem these vans had which is they get air trapped in the heater core which makes it difficult for coolant to enter the heater, This is why it only works when the engine is revved.

I would make sure the coolant is full then start the engine and turn the heater on full blast. Then raise the rear of the van as high as you can used a jack. This should allow the air to "Burp" out.

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

I have seen them do the front as well FYI.

This guide can help as well

https://www.2carpros.com/articles/car-heater-not-working

Please let us know what you find.

Cheers, Ken
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Friday, February 10th, 2012 AT 9:02 PM
Tiny
EVILPUPPETMASTER
  • MEMBER
Thanks for your response. The coolant has been flushed twice. First time when changed thermostat, and second time when I Flushed heater core. The coolant level in the reservoir is where it's supposed to be when cold. I think that vehicle does not use vacuum operated controls. They should be electrical. When I switch from cold to heat and other way around I can hear the actuator switch.

I can check the vacuum on the engine using my vacuum tester and let you know. Let me know if you have any other suggestions.

Thanks,
Alex
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Friday, February 10th, 2012 AT 9:07 PM
Tiny
FIXITMR
  • MEMBER
Also, does heater core plumbing have bypass hose? This can be a problem with core flow as it allows flow to bypass.
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Friday, February 10th, 2012 AT 10:46 PM
Tiny
CJ MEDEVAC
  • EXPERT
How about a simple, "feel the hoses" as the enter the firewall into the heater core.

If they are really hot at normal operating temperature, and cool air is being blown out of the heater inside the car. Something inside/on the heater box is malfunctioning.

That is, if it is not bypassing, like fixitmr suggested in his link.

If a heater hose is crimped or twisted, it could inhibit flow also.

Keep us posted.

The Medic
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Saturday, February 11th, 2012 AT 4:44 AM
Tiny
EVILPUPPETMASTER
  • MEMBER
Thanks for your help guys. Great site by the way. Okay, got some very good news but before I go into it I will answer your questions.

No bypass hose or heater control valve on this car. The only hose coming of heater core outlet goes to the throttle body cooling line (this throttle body needs to be cooled with coolant).

Both hoses coming into the firewall were cold until you rev and hold 2000 rpm. Then they become warm to the touch and then after thirty seconds back to normal room temperature. So my solution so far. :)

It seems that there was air trapped in the system.

What I did:
Took it for the twenty minute drive. It would only start heating at about 2000 rpm. Once it goes down, no heat. ( I am in Canada and it is -20 today. :)

So came back to the garage and decided to "burp" the air from coolant reservoir while the car was hot and thermostat was open and jack up the car like you said.

I know that this is not very good idea because it is under pressure but I did it slowly. While releasing the pressure I noticed that coolant started rushing back into the reservoir trough the overflow line but it was not steady flow (air was coming in). Once the car cooled down I noticed that now I have less coolant than before I drove it. I thought it was a good sign since the air has been pushed out from the system and in its place now we have coolant.

So started the car and it started heating as it is supposed to at heat on idle. I repeated this same test next morning and again got the heat almost immediately after start-up.

I have heat. Let's hope that it stays like that. I have another question related to my alternator but I will ask that in another thread.

Thanks again for your help.
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Saturday, February 11th, 2012 AT 3:11 PM
Tiny
KEN
  • ADMIN
Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help

Cheers, Ken
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Wednesday, January 31st, 2018 AT 3:41 PM
Tiny
ALADINK2
  • MEMBER
  • 2006 FORD FREESTYLE
  • 3.0L
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 156,000 MILES
No hot air while on park or while the vehicle is not moving. But get hot air as soon as the vehicle starts moving/driving
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Wednesday, January 31st, 2018 AT 3:42 PM (Merged)
Tiny
HMAC300
  • EXPERT
Try cleaning your battery terminal ends and make sure that coolant level is full.
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Wednesday, January 31st, 2018 AT 3:42 PM (Merged)
Tiny
ALADINK2
  • MEMBER
Yes, Coolant reserve tank was empty. Thx for the tip. Now I need to check why/how it got empty?
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Wednesday, January 31st, 2018 AT 3:42 PM (Merged)
Tiny
HMAC300
  • EXPERT
Have apro pressure check system it may be a head gasket leaking internally
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Wednesday, January 31st, 2018 AT 3:42 PM (Merged)
Tiny
2CARPROS-ARCHIVES
  • MEMBER
  • 2005 FORD FREESTYLE
  • 198,000 MILES
How to bleed air from heater core.
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Wednesday, January 31st, 2018 AT 3:42 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
Run motor at 2500 rpm till you get heat. Make sure the level is checked often

Roy
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Wednesday, January 31st, 2018 AT 3:42 PM (Merged)

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