Jaguar S-Type (1999 - 2007) - 99 inefficient heating, any ideas?

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Sun 16 Dec 2007 21:11
99 inefficient heating, any ideas? - Westpig
it would appear that the heating side of things in my 1999 S Type is not what it should be. I usually drive all year round with the climate on 22 degrees and haven't noticed anything wrong...however with this really cold weather i cranked it up a couple of degrees and didn't notice any difference.

having played around with it i've noticed that a/c or no a/c it is difficult to get the temp up above tepid......the best it will do is if you leave the car ticking over for 15 mins first it will then come out warmish, but certainly not hot

it will however clear ice in the morning as the tepid is warm enough to do that, albeit probably not as efficient as it should be

anything obvious?....

Edited by Pugugly {P} on 16/12/2007 at 21:21

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Sun 16 Dec 2007 21:29
99 inefficient heating, any ideas? - Dynamic Dave
If the temperature gauge isn't coming up to operating temperature, then I would have said the thermostat needs changing.
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Sun 16 Dec 2007 21:50
99 inefficient heating, any ideas? - elekie&a/c doctor
Check the coolant level first.This model has warning lights for everything except low water.Also it is possible that the electric heater water valve is playing up.(very common fault)and thus not allowing sufficient flow thro heater matrix.hth
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Mon 17 Dec 2007 14:45
99 inefficient heating, any ideas? - Westpig
thanks....something to check........the engine running temp gets up to normal quite quickly
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Tue 18 Dec 2007 16:31
99 inefficient heating, any ideas? - Westpig
thanks gents.... after a trip to my mechanic, the diagnosis was:....coolant had got a bit low and being hard to check wasn't noticed....was difficult to top up as well because of an airlock....but all is well now

when you have limited mechanical knowledge you worry about all the expensive things
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Tue 18 Dec 2007 16:56
99 inefficient heating, any ideas? - RichardW
"when you have limited mechanical knowledge you worry about all the expensive things"

Hmm, the coolant went somewhere - it's not a consumable. It could still be expensive.... Keep an eye out for signs of coolant leakage (crystalline deposits) on hoses, the rad etc, and look out for signs of water leaking under the car overnight if you can. Best keep an eye it, because low coolant = overheating = possible £££££ (depending on the engine).
--
RichardW

Is it illogical? It must be Citroen....
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Tue 18 Dec 2007 17:11
99 inefficient heating, any ideas? - HensTeeth
Hmm, the coolant went somewhere


Indeed. The coolant expansion tank has a habit of cracking and leaking - if it were mine, I'd keep an eye on the coolant level and see if there were any regular drips on the floor behind the driver's side front wheel.
There's a list of common faults (including this) for the S-Type over on the Jaguar forum on this page:

www.jaguarforum.co.uk/viewtopic.php?t=5336


Hope that helps.
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Sun 24 Feb 2008 18:16
99 inefficient heating, any ideas? - Westpig
rude of me not to have replied earlier.....some spot on advice on here...took the car to my usual independent when the heater played up again (used a local mechanic the first time).. and the diagnosis was...

dodgy heater valve and slight split in plastic header tank......so the advice from several of you was top dollar..thankyou

now if only at least one of you had foreseen the fly by wire throttle being a nuisance as well, that would have been quite handy. January was an expensive month...:-)

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