I have very little heat on the driver side floor and vents of my 2007 XK Jaguar Coupe. When I go from cold to hot it only gets lukewarm on the floor and dash vents. The passenger side floor and vents are hot and as they should be. I believe the problem is with the Drivers Side Temperature Blend Door as my diagnostic scanner shows the Drivers Side Temperature Control Motor operating correctly. Is the blend door broken or is there another issue going in here.

Robbie

 

Could have a partially blocked heater core. That or possibly the aux coolant pump isnt working to its full potential.

 

[QUOTE=Rummy636;2347047]Could have a partially blocked heater core. That or possibly the aux coolant pump isnt working to its full potential.[/QUOTI

I replaced the booster pump and it did no good. Going to flush out heater core and see if it makes a difference.

If not then I have a new replacement copper heater core. Do you need to pull the dashboard out of the car to replace the heater core? Alldata shows. door/panel but I can not find it.

Thank you for your help,

Robbie

 

Heater core failure is likely certainly. But first, you checked the temp of both the ingoing and outgoing heater hoses (using and IR thermometer), or even by hand?
A blocked core would likely leave one side cooler. Also see the attached TSB. Not our vehicle but the test process should be the same or similar.

Problem could also be flaps. Are you getting any codes? You need a Jaguar computable scanner to get climate codes.
Also worth checking is the aspirator.

I haven't read of anyone getting the heater core out without removing the dash. Maybe it can be done but I don't know if anyones. tried. There is a great write up in the sticky DIY thread on how to remove the dash, Seems like it would add a couple hours to the job. Not terrible.

 

Sean,

Thank you for the tips. there are no codes showing up. With my diagnostic Tester I can activate all the motors that control the flaps and get a read out of them open and closed. they are reading all the same. What troubles me is I drove the car on a coffee run and had hot heat but when I started the car to return home it was cold. I have to wonder if the shaft on the driver's side temperature control motor is broken. I had the dash and console out if the cat to years ago to replace the A/C condensation drain tube.

This is what AllData says to do to replace the heater core:Heater Core (80.20.29)

Removal

1. Raise and support the vehicle.

WARNING: Do not work on or under a vehicle supported only by a jack. Always support the vehicle on safety stands.

1. Remove the cover and disconnect the battery ground cable.
2. Remove the heater and evaporator core housing.
3. Remove the RH side footwell heater duct.

•  
  • Remove the 2 screws.

1. Remove the heater core.

•  
  • Remove the coolant pipe clamp.
  • Remove the screw.
  • Remove the heater core retaining bracket.
  • Remove the screw.
  • Position the RH footwell duct mounting bracket aside for access.
  • Loosen the screw.
  • 6: Remove the heater core, inlet and outlet pipes.
  •  
    • Release the 2 clamps.
    • Remove and discard both O-ring seals.

Installation

1. Install the heater core, inlet and outlet pipes.

•  
  • Install new O-ring seals.
  • Install the clamps and tighten the screws.

NOTE: Lubricate the seals with coolant.

1. Install the heater core.

•  
  • Secure the heater core retaining bracket.
  • Install the screw.
  • Install the coolant pipe clamp.
  • Install the screw.
  • Align the footwell duct mounting bracket and tighten the screw.

1. Install the RH side footwell heater duct.

•  
  • Install the screws.

1. Install the heater and evaporator core housing.
2. Connect the battery ground cable and install the cover.

THE BIG QUESTION IS WHERE IS THE COVER THAT THEY SAY TO REMOVE TO REPLACE THE HEATER CORE? NO MENTION OF REMOVING THE DASH.

Again, Thank you for your help,

Robbie

 

Ah. Ok, I think they mean remove the panel that hides the battery.

Do yourself a favor and download the 06-09 workshop manual here for free
https://www.mediafire.com/?2ssiyne7ma1fs

I think you're missing some information. I don't see this in your list above and you may have edited it out, or AllData didn't include it. The manual also has some drawings. Not sure what AllData provides.

"Remove the heater and evaporator core housing.
For additional information, refer to Heater Core and Evaporator Core Housing (82.25.21)"

I know guys in the X350 that have been able to remove the core with our disassembling the dash as the x350 manual states so it may certainly be possible.

 

From your description, this is not a TEMPERATURE or VOLUME issue as the passenger side is giving out hot air but driver side is not - it is a heat DISTRIBUTION issue. This discounts the heater pump or matrix or the passenger side would not be hot.

Volumetric output is determined by the positions of the blend doors which are moved by 5 Servo Motors in the AC/Heater Unit. If the volume of air delivered at the outlets is normal, the Servo Motors must be OK.

The XK has a dual climate system where left and right sides temperature and boost can be set independently. These settings are made using the dash switches and applied by the ATC (Automatic temperature Control) module. This temperature differential issue between the left and right sides despite manual settings suggests this could be the problem.

There is also a cabin humidity and temperature sensor behind the Instrument Pack veneer which factors into the equation. It can get covered in dust and throw out signals to the ATC.



This was my 2007 XK (RHD) with the veneer removed to access the sensor.

Graham

 

Graham,

Thank you for your insight. I will look into your suggestions as soon as I can get time and my lift free of the Triumph GT6 Hill Climb project.

Can you steer me in the right direction as to where the ATC (Automatic temperature Control) module is located?

Thanks again,

Robbie

 

Robbie,

Apparently it's on the end of the Air Inlet Duct casing (see item 1):





I (fortunately) have not yet had to make direct acquaintance with it.

Graham

 

My wife's old Grand Cherokee had a door control break in 2011. I had to remove the entire dash to fix it.
It had the same symptoms; heat only on the driver's side, cold on the PAX side.

 

Robbie, as you can see from Grahams pic, the entire heater/evaporator unit is under/behind the dash. The numbered parts are above the passenger footwell. The ATC is fairly accessible. Open the passenger door slide the seat all the way back to give yourself room and look up under the passengers dash under scuttle above the footwell. I removed mine once. I think it's just 2 screws and the connector. Keep us in the loop.

 

Sean,

I have too many paying jobs that need to be done before I can look at the heater issue. If I ever get caught up I will take your and others advice and see if we can fix this issue.

Thank you all of you guys,

Robbie