Hi all
Bit of a twist to this. Have no heat at any setting including hi. I have just fitted a new heater pump. I understand the valve defaults to hot so I'm not looking there. Before I changed the pump I checked all fuses on the car and have checked the relay that I think controls this pump( very confusing in the owners book) could someone confirm which relay it is?? I have only .8 volts taken from the pump supply plug, yellow and black! Any ideas??

Geoff

 

My lack of heat was due to the heater core needing to be flushed, I took mine to a specialist car radiator shop, cost 80 bucks for a flush and refill.
Beware the water pressure to homes is higher than what the heater core is made to withstand, some people have used garden hoses anyway and flushed it, each to their own.

 

Same here. Second winter in a row I needed to flush heater core to get heat back. Did it myself. Takes a bit of dexterity but not impossible. As Jonathan says, beware of the water pressure. But it basically was a close to free job (well, had once spent $5 for a hose extension and the price of coolant replenish which volume was relatively minimal) and second time around accomplished in less than 2h. If interested, I can take you through the steps.

Cheers

 

Hi Blue,
I have no heat since a few days ago, but noticed when I got the car 3 months ago it didn't heat like a V8 should, so planned to investigate.
I have an LPG conversion so my firewall is a busy place. I can't see the heater pump and don't know what to remove to make it accessible - so could you go through the steps you took, especially what you removed to access.

I plan to disassemble the pump and check the brushes - why not anyway - but do you then need to flush and re-fill the whole system? The instructions I have seen in other threads mentions a cap somewhere that you should open to bleed the system, but I can't identify it either
I do most of my own mechanics on cars and bikes, but this Jag has so many special bits called weird names, locating the right bits is tough!

BTW: I also have a problem with idling from cold (sometimes, not every time) could this be related?
I have so many problems to fix on this car...I can see why they sell for so little after a certain time. Unless you are an enthusiast, with lots of patience and love for the car, it is one to walk away from.

 

Just noticed I forgot to change signature when I swapped cars 3 months ago.
I now have a 3.2L XJ8 Sport

 

Here's the drawing. Black is ground, yellow is power from relay #1 in the engine compartment. Pulling the relay and jumpering pins 3 and 5 should make the pump run if it's okay and the ground is ok. Check the ground,they can be a problem on a Jag.

However, if you only have 0.8 volts, there's your problem. Ignition on? Engine running? Try swapping a relay with another one, they're all the same.

The relay is operated by the air conditioning control module, plus there's the fuse to check as well.

[IMG][/IMG]

 

Having same issues here going to check the relay next.

 

Same here. But I live in LA so I'll watch this thread and deal with it in Nov

 

Lol usually I could say the same being in Coastal N.C. but it was 78 degrees FH yesterday, tonight they're calling for a wintery mix (shakes head).

 

Hi Guys:
Sorry for late reply but could not log on for some reason.

So i have resolved this by changing the pump (whether needed or not) and finding that the pump fuse had blown. Having fitted the new pump i still had incorrect voltage so after investigating further found that the fuse also controls the active sounder for the alarm and the fog lights. I unplugged the sounder and the fuse no longer blows, heat in car and working fog lights. So now is all right with the world, i just need to find a new sounder unit. Apparently this is not unhered of this side of the pond.

Hope this helps someone!!

Geoff

 

I would wholeheartedly agree with this. These machines ARE NOT for the "average Joe". Unless you LOVE a good challenge, have time, and experience (not necessarily with Jaguar!), .....STAY AWAY from them! That philosophy brings the market value of these cars WAY down, and that's what I LIKE (I think of myself first, and than about everyone else,.....selfish?).

Parts are cheap (new OEM, recycled, whatever). It's TIME that's expensive, so one needs to DIY. If I would have to pay someone to diagnose, and fix one of these that were on the road for 13-15 years, I'd go broke. There are PLENTY of brand new cars with "bumper to bumper" warranties to drive, that cost less per month, than maintenance on one of these IF you are paying for maintenance.

Example,.......I fixed "check coolant level" on my 2006 Range Rover over the weekend, for $45 bucks, and 20 minutes of my time. Dealer said (and I quote!): "One hour diagnostic time MINNIMUM, plus parts, and labor to replace", I don't have to tell you what that would cost, do I?

People I know think I'm either filthy rich, or dumb as a door nail (most think I'm both!) for driving Range Rovers and Jaguars. I like them, I LOVE the challenge, and I have "know how". My experience is strictly as a hobbist, in about 45 years of wrenching on motorcycles, airplanes, cars, and guns. Just for fun. Some poeple get frustrated by trying to figure out mechanics of ANY machinery, and I get relaxed. It takes my mind off of my business dealings, realestate ventures, getting old,......stuff like that.

So,......either learn, practice, and enjoy,.....or, if you don't enjoy the challenge and work, go buy something new with bumper to bumper warranty, and know that transportation WILL cost you. Either in monthly payments, or in parts and stripped knuckles.

But I'll tell you,......there is hardly better feeling (well actually I can think of few!) than being able to figure the problem out, work around the stupid design, and fix it yourself,.......for a pocket change!

 

Pretty much agree, especially stripped knuckles and "I can think of a few" (broads, fine bourbons, and Dry Creek valley zinfandels, come to mind).

Used to have a bumper sticker that said Give Blood, Play Rugby: would suggest unwinding bolts on a Jag takes blood as well.

 

Which pump did you go with?

 

Local jag specialist (Berkshire Jags) rebuild them About £75.00 + core

Sorry in UK!

Regards

Geoff

 

Hell of a well sorted deal!

 

Thanks Danielsand, I'm with you entirely! my work colleagues think I'm crazy coming in almost every day with a new, exciting challenge to correct something else that is acting up on my car.
Last week the idle became intermittent (any ideas gratefully received) and this week I have no heater. I still think these may be linked.

Can anyone recommend a flushing product and suitable replacement antifreeze available in the UK, as I think this sensible to do when doing the pump?
I have ordered the brushes to fix myself and I may make a youtube video of the job.
Big thanks to Racediagnostics for his thread and pictures here:
Heater pump repair.

 

Hi Geoff, After work today, I followed the electrical diagnostics in this thread and discovered I too have no power to relay 1 of the LH engine compartment fusebox, and also no fog lights any more (front or rear). Fuse 15 in the same fusebox seems fine, but that power won't go anywhere until the relay pulls in. So where is the fuse you found, please? And where is the sounder in case I have the same fault?
I'm getting frostbite driving this car!

 

In the wiring diagram above, "5" is the power supply direct from the battery. This has to be present. I doubt it's missing, because you'd have a ton of things not working.

44II is a fused source from the engine bay fuse block. Check fuse #3, it's a 1 amp. It also supplies the foglamp relay, so that's the likely culprit.

[IMG][/IMG]

 

Polibon - sorry for late reply. Still interested in the steps to flush the heater core?

Cheers

 

Thanks avt007, all sorted now! The sounder was the culprit. In the recent flooding we've had here I drove through lots of deep water...and probably shorted the sounder.
This took out Fuse 3, which isn't documented in the "vehicle care" manual, as supplying the heater pump. I spoke to Maybach_man last night (yes, talking, a radical concept I know...) and he told me of the same scenario so I now have heat again.

Brian: Blue XJ8, yes please provide flushing steps, I still plan to rebuild the heater pump and flush the system. My car has only done 5k miles in the last 6 years, and I don't think that's good for any car, so plan to do a major service myself...when the weather warms up.