yr2000 - heating problem - SkyDragon
I'm having a problem with my 2000 W-Reg Jaguar S-Type - Basically, the heating system doesn't work. The A/C works, and all the rest, but when you put the setting to warm, cold air comes out. No matter what setting you use, it's still cold air that comes out, and I've tried various combinations to make sure that there is no other way to make it work. I'm assuming that maybe the heater is broken? Radiator? Some wiring somewhere? (Although I doubt it, since everything else works perfectly). Anyone else had this problem? And what happened? Thanks.

Edited by Dynamic Dave on 20/11/2007 at 21:06

yr2000 - heating problem - elekie&a/c doctor
The most common problem on this model for a non working heater is a failed electric duo water valve.It is situated at the front of the engine bay ,low down on the front subframe o/side.Usually needs a replcement unit and access is a little awkward.Last one of these I fitted cost around £120 for the part.hth
yr2000 - heating problem - docwats
This is too funny. I recently purchased a 2000 S-type, 4.0 with 60K miles in really good shape but discovered exactly the same problem described in the message about the heater throwing cold air. I changed the thermostat and flushed the system with no real improvement. I finally took it to a local Jag dealer and they quoted me $2000 to change out the heater core. I've been working on my own cars for 40 years and basically didn't believe them and asked if the core failed why it wasn't leaking. They were surprised I asked but said it eventullay would if I didn't replace it. Give me a break!

The thing that really struck me is when I flushed the system, the car didn't drain alot of coolant as I expected. I figured there may be a blockage or some valve that wasn't opening and then I read your e-mail response to the person who had the same problem.

I even saw this valve when I was under the car but wasn't certain what it was until I started looking at the system components on the internet and wondered if this is the problem.

You have kind of confirmed what I should try next before tearing the dash apart and I plan on buying the service heater valve at $226.99 in California and replacing it myself.

I don't have a manual yet, do you have any tricks or suggestions before I start?

I really appreciate this type of exchange.

Thanks
yr2000 - heating problem - elekie&a/c doctor
Access to this heater valve is even more tricky on the 4.0 model.Assuming that it is fitted in the same place as rhd cars ,then the best way to replace it is from underneath the car.Remove the engine bay undertray (if fitted)disconnect the coolant pipes from the engine bay components,some are clips,some are quick release fittings .Remove the valve from its mounting bracket with the flexi rubber pipes still attached.You can then swap pipes to new valve or fit new.hth
yr2000 - heating problem - John Roadrunner

I have a 2002 3ltr petrol S type and suffered the same problems as in this discussion thread. After reading the comments I decided to drain the system. As with your comments the underneath bottom panel has to come off (real hassle) after that it was pretty straight forward. I drained the system flushed it through with water. After doing this a couple of times I decided to run the engine standing and there was no improvement. Flushed it through again and took it for a spin. The heat started to flow so I kept going down the motorway changing the heat setting from hot to cold to get the valve moving. Fortunately this seemed to work. I then drained the system again and refilled with antifreeze. I have used the car daily for a week now and the system seems to be working well, fingers crossed it will continue. If it does I will be doing the same thing next year.