Its getting pretty cold up here in the North East and my 2005 Super V8 doesnt have much heat up front. The rear is great but with the front climate set to HI it feels like outside air on my legs or maybe a bit warmer than outside air but not much. Every once in a while it gets warm but most of the time its cold. Is there a blend door or actuator motor I should check. It acts like an air temp blend door thats hanging up but I dont even know where to begin looking or how to access it. If anyone has been under the dash or has a good idea of what may be the trouble it would be a great help. Thanks all!

 

If you are getting heat, albeit in the wrong place, then the heater radiator would seem to be OK, (they can silt up), and the fault lies elsewhere, maybe as you say with flap valves or something. Does your car have separate controls for front and rear ? It might be a temperature sensor problem. Really these things need an expert as they are rather complex.

 

I wish I could find an answer to this exact query as I suffer the same. My feet are freezing and even by switching to recirculation, cool air gets pumped to my feet all the time, even with the heating on face or screen only. When I select heat for my feet, it is barely warm. When I select face and feet, face goes cool and feet stay cool.

And all I really want all the time is what I can't get - FEET HEAT!

I suspect the outside air flap seal is adrift as I also get a flapping/rubbing noise from the drivers side (right side - UK) when the fan is turned up, like a playing card caught in a bike's spokes. This may be the cause of all this.

Does anyone have any diagrams or can point us in the right direction to get some, plus some instructions as to how to investigate this problem, please?

 

Mike
Check fuse F8 in the boot fuse box it may be blown if it is it could be your auxiliary coolant pump that pushes hot coolant to the heater core. I had the same issue and my aux pump was bad.

 

My XJR has a separate heater core and blower motor for the rear heat, its in the rear of the console. FWIW.

Stu

 

Thanks for taking an interest. I have checked all the fuses in the boot fusebox next to the battery and all are ok. The temparature sensor appears to be working as the screen and face vents react to changing the temparature on the control panel. I get heat shortly after starting the car from cold so I believe the auxilairy pump works and indeed I have checked it externally by feeling it vibrate and feeling the temparature of it change. The face vents supply very hot air when asked as do the screen vents.

Yesterday I got copies of the service manuals covering the heating and ventilation system off this forum and so armed with a little more information last night I spent some time checking air flow whilst the car was stationery in the garage. It seems the footwell heat was quite good then, when the temparature was turned up high.

I opened and closed the recirculation flaps and determined there was a healthy flow of air into the car from the scuttle in front of the windscreen and this diminished when the recirculation button was pressed, as you would expect. But it did not stop entirely I think, the pressure into the car just reduced significantly.

It seems to me that when driving, fresh air is getting into the car whatever the demands of the heating system are. So if I turn the temperature up I would expect the cool outside air to diminish somewhat, but it doesn't. When driving this has a ram effect, so any gap in any flaps will still allow a good amount of air in as it is under pressure.

From the disgarams I have seen, there is a fresh air vent or "cool air bypass" as it is called in the diagram, which seems to be directly below the scuttle entrance holes. I think this is the culprit here. I think it is stuck open or not closing properly.

Perhaps it is broken, perhaps the seal around it has come away (especially if it is a foam seal).

So where do I go from here? I would like to access this flap, but suspect someone will tell me that is a major job not for an amateur. Will it involve dashboard out and if so, is there a procedure I can follow?

Or has anyone got any sneaky fixes?

Is there any point removing the outside scuttle and poking around down the entrance vents?

Is it perhaps safe to block the scuttle vents completely to see if that cures the problem, or is this the only way the blowers get their air feed? The diagrams I have seen don't make this clear.

 

This is a fairly common problem, but the symptoms are usually that the drivers side is cold and the passengers side is warm. The common repair is to backflush or replace the heater core which gets full of crud from the cooling system. I have rarely heard of blend flap problems in the X350.

 

Mike,you are in the wrong section my friend, this is for x350's.

 

Ah well... I will start a new thread in the right place. Seems to be a problem with the whole range though!!

 

Hey Oldmots, my 04 XJR is doing the exact same thing: cold on the drivers, normal on the passenger (also the back seat vents blow cold). It's chilly in Chicago and hopefully a radiator flush and fill will do the trick, you think?