www.jec.org.uk

Hi all.

I am gradually rejuvenating so called climate control .

Cooling needs replacement air conditioning compressor.
Heating works OK. Good heat output, regulation of internal temperature I.e blows hot air into car until up to temperature when blower fan reduces speed and air temperature exit is reduced.


My problem: when observing water valve it moves up or down according to temperature selection but when cold is selected water leaks from valve.

Car is 93 6.0l XJS coupe .

Any ideas please ?

Paul,

My 4 litre started doing the same thing last year. I left the temp just tuned up enough to stop it from dripping until I was ready to do the job.

As part of my recent project to install a coolant pre-heater, I decided to also change the leaking heater valve. I also changed the rubber pipes either side of it. In my experience, they can be really quite tight to remove!

I think the valve on your 6.0 V12 is C41051

It's a good excuse to do your regular coolant change anyway. Remember to follow the very specific bleeding procedure for the V12 when you refill the coolant.

Good luck

Paul

Hi Paul, thanks for taking the time to reply.

I've taken your advice and left temp turned up slightly to keep the heater water valve open to stop water loss while obtaining parts.
C41051 seems to be no longer available from Jaguar UK, so oem or pattern part needed.

Will certainly take your advice and replace water hoses adjacent although the location on the vehicle next to the firewall looks horrendous for access.

Expect lots of skin loss from knuckles during replacement!

I managed to get a heater valve from Jaguar only 18months ago! That's quite disappointing they have run out. David Manners has still got them though.

Original:
http://www.jagspares.co.uk/Manners/part ... tno=C41051

Pattern:
http://www.jagspares.co.uk/Manners/part ... CBC2536%2A

My knuckles still hurt from refitting this recently after my water rail rebuild!

SNG Barratt have a copy C41051. But several Jaguar DIY authorities recommend a plastic version that doesn't suffer the problems of the tin one (not that I've ever had any problem - touch wood). I thought Barratts flogged the plastic one as an alternative, but I can't see it on their web site - might be worth calling them though; their staff are very knowledgeable and helpful.

Thanks to all for taking the time to reply
(Both Pauls and XJR-S)

I initially placed an order for C41051 (heater water valve) from British car parts whom have given good service previously.

Subsequently I was informed that they no longer sold the part. I had the heater hoses on order from Jaguar heritage as the hose to the heater valve developed a leak.

Managed to order C41051 from Berkshire Jaguar components by phone, excellent service, placed the order at 4:30pm and goods arrived at noon the next day.

My intention was to replace three hoses, item numbers 20, 22 & 23

Ended up just replaced heater valve and hose 20 as 22 (heater outlet hose) was inaccessible, don't think it could be replaced without raising the engine.

I've done a couple of hundred miles since and all seems well, also got round to replacing the thermostatic switch for auxiliary fan, this had been replaced by myself last year but I used a pattern part which stopped working after a few months.

Hopefully the genuine part from Jaguar heritage will last longer. With the arrival of British summer weather it's reassuring to hear auxiliary fan switch on after hot engine switch off and when in stationary traffic.

I too have a spare heater outlet hose, 'cos I couldn't see a likely way to replace the old (not yet leaking) hose; removing it looks easy, but getting the new one on is a fish of a different kettle.

I have recently replaced my engine in a series 2. Now, however, I get no warm air from the system, although I can direct the air flow properly. I guess that either I have an air lock in the heater matrix or the heater valve on the bulkhead (C41051) is non functional. Any advice? Alec G.

If you attach a tube to the valve and supply vacuum by sucking you should see the arm on the valve operate. The valve is normally open, vacuum to close. It would be unusual to fail closed so I suspect the problem lies elsewhere.
Al

As Pop says, try applying vacuum to the valve to see if it moves. Is it possible that a vacuum pipe has become detached?
Also feel the hoses either side of the valve for heat. If it's hot going up to the valve but cool after it the the valve is obviously stuck shut but this is uncommon.
More likely would be an airlock in the heater matrix.

Thanks for your observations. I will attend to it when I return from holiday. Alec G.