Interior heater not warm?

[GunMentalGrey]

Hi all, I’ve had a bit of a search but not found a solution yet.

My heater is playing up in my D40 STX 2007. Intermittently it doesn’t blow warm air once the engine has warmed up. Up until maybe a month ago seemed to work well, although I really only use it in winter. This morning at max temp in the dial barely warm air was blowing out AC on or off didn’t make a difference. Turning the dial to cool and back didn’t seem to help, like my last car that would ‘forget’ it’s settings.

I replaced the fan control resistor recently, so that is working properly and the AC certainly cools things down nicely.

Any hints? Thanks in advance.

 

[Old.Tony]

I wonder if your coolant hoses are connected and intact? There are two hoses that go in through the firewall to provide heat in the cabin. Are these connected, or has someone disconnected them and joined them together to prevent coolant from entering the cabin where the interior heater matrix may have been leaking?

 

[GunMentalGrey]

I’ll have a look, but he heater has been working properly (as far as I know) for the few years I’ve owned it. Had full heat yesterday, seems intermittent - the worst kind of fault.

 

[ericcs]

how easy is it to access the heater tap to check it's operation. maybe the dash control is not sending the signal to it all the time?

 

[GunMentalGrey]

I drove it again this morning. This time checking the air temp and it seemed to be warm initially the fan was turned on, then cooled off to only just warm. Makes me wonder if the heater hoses are blocked and not enough hot water is passing through the heater core.

 

[amber.2]

Sounds like the heater core could be blocked, feel the hoses from under the bonnet and see if both are hot when the heater is in the on position. If only one is hot the water is not passing through.

 

[joe2006]

If the hoses are hot perhaps it could be the air temp mixer door motor/actuator?

 

[Nomadic Navara]

Duplicate post. Can't see how to delete

Look down in the bottom LH corner of your signature block. You will see a link in red labelled "Report." Use this link to report it to the moderators. They will fix it.

 

[grumpy too]

Is your temp gauge showing normal temp and is there plenty of water in radiator, it looks like it would be very easy to get an airlock in these motors or at least the d22 version, water comes from the engine block outlet back through the undulating hoses via EGR cooler to the heater before going back into the block with I think an offshoot to the turbo.
Is there a valve inside the cabin haven't looked yet, if there is it is electrically operated.
Hey that fan control resistor is a dog to replace hey, noticed on mine it was only a solder blob had melted causing the problem.

 

[Bobtee]

Hi all, I’ve had a bit of a search but not found a solution yet.

My heater is playing up in my D40 STX 2007. Intermittently it doesn’t blow warm air once the engine has warmed up. Up until maybe a month ago seemed to work well, although I really only use it in winter. This morning at max temp in the dial barely warm air was blowing out AC on or off didn’t make a difference. Turning the dial to cool and back didn’t seem to help, like my last car that would ‘forget’ it’s settings.

I replaced the fan control resistor recently, so that is working properly and the AC certainly cools things down nicely.

Any hints? Thanks in advance.

Had a similar problem with a new motor in my old D40 2009. Turned out to be a blown head gasket causing air lock. Check compression!!!

 

[GunMentalGrey]

Temp gauge is showing normal and not going high at all.

Haven’t made the time to look at it yet. But this weekend will probably need to do something as additionally now it is stalling on startup after it’s been sitting for a while. Like the fuel is draining back to the tank, same symptoms as when my primer bulb was split and allowing air into the fuel lines.

 

[landmannnn]

Have you bled the cooling system?

 

[GunMentalGrey]

Flushed and refilled the coolant and solved the issue. I think it was a little low, but didn’t really check it before dumping the radiatior contents as it was due anyway.

 

[grumpy too]

IMHO they have a terrible coolant system and very prone to airlocks but did refill according to the manual (slowly) on one here and it seemed to fill ok but the other one had to refill three times to finally clear the airlocks.
If you look at the supply to the heater it goes from the engine outlet, up and down to the EGR then up and down along the side of the engine then up to the heater.