My heater core appears to be leaking (I lose coolant and it smells like ethylene glycol ONLY when i run the heater), so I'm about to embark on the apparently painful task of replacing it.
I picked up a used one on ebay, seems fine, doesn't leak. It came with the inlet and outlet pipes attached, as well as the firewall grommet. I'm wondering, hoping really, if it's possible to install this replacement WITHOUT removing the pipes from the core flanges? Has anyone tried that? Seems like getting the pipes to seal on the installed core flanges is the worst part of this job, and it would be GREAT if i could just loosen the joints and slip the unit in while pushing the other ends through the firewall.

If someone has successfully tried this, please let me know what tricks I need. I'm going to try it this way first, and will report back if its possible.

Thanks
Rick

 

I would rethink the decision to install a used heater core.
As you said it is a very difficult job and these cars are known for plugging heater cores. I would ONLY use a new heater core!
Just too much chance of having to redo it over again.
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+1 on the new heater core.

 

It may not be leaking but it would be a good idea to ensure that it's not partially blocked also.

I have done this by running hot water through the core and feeling to see if it all heats up.

I don't think that you can do what you are proposing because even if you disconnect the hoses

on the engine side you can't move the pipes because the core is fixed and you can't slide the core out because

the pipes are through the firewall.

If I had to do this job I would do this:

Remove glove box

Clamp hoses in the engine bay

With a tray in place to catch coolant break joints

Allow to drain

Remove clips and pull out core

Clean and dry pipe joints

Install 'new' core

Replace 'o' rings in joints if needed and close up with a good sealant

Leave to set/dry overnight before topping up coolant

Run engine and maybe drive around until coolant up to temp

and heat on both sides

If no leaks

Replace glove box

NB I have not done this job myself........................................but I have a spare used core , if and when.

 

I am a bit puzzled, because coolant is running through the heater core the whole time the engine is running. On V8 cars there is a pump to assist circulation. This pump may not run when heat isn't needed, so the circulation is less.

Anyway, my experience was that I had a new heater matrix fitted due to blockage of the old one. In theory, one can get it flushed, but it is usually not successful, so you pay money out to no avail. However replacement is not as huge a job as you might think; if anuybody tells you the whole front dash has to come off they are talking absolute nonsense !! All that is done is the glove box has to come off, then the blower fan. The matrix is then exposed for removal. My core was done by the local Jaguar main agent, and the most expensive part was the kit for replacing the matrix !! Labour time was 3 hours, so you can see it is not especially difficult, but the key thing is the O ring seals and I think they replaced those at the firewall as well as where the pipes join onto the matrix, Unfortunately, I don't have the invoice because I part-exed the car in January 2019 and geve the service records with the car. Somebody else is now running around England in it.

 

Hello Fraser,
This is going to seem a little weird and I am probably being a bit stupid?

My dashboard air registers are making annoying gurgling sounds as soon as the ignition is switched on (even if the climate control is switched off). I can clearly hear my auxiliary pump operating. If I select heat, my driver's side is not hot. All the symptoms of a partially blocked heater core? I have read every post in our Forum on this subject and the overwhelming opinion appears to be replace the heater matrix?

The thing is, I live in Dubai and accordingly, I never, ever use the heater?

If I were to disconnect the rubber inlet and return pipes from the aluminium pipes near my radiator and (literally) just join them (the rubber pipes) together so that the heater core was then disconnected from the system, do you think this would eradicate the annoying noises please?

Or would it somehow affect my air conditioning?

I did say my post was weird!

Regards,
Ray

 

After looking at the drawings of the cooling system.

It should work.

Just make sure the pipes are not going anywhere else, then try it.

I would block the pipe openings if it works out for you

A piece of the same size hose connected would work

Good Luck to you

 

Thanks for your reply Wingrider,

it is 23.45 hours here (my football team, West Ham United have just lost) and outside it is 27 degrees C on December 5th. It gets down to maybe 20- 24 degrees C in January, the coldest month.

Perhaps I could simply insert a few inches of 3/4 inch pipe fastened with a couple of jubilee clips between the inlet and outlet pipes, so that should any future owner wish to heat his/her car here, they can choose to do so?

I just want to get rid of what is a quite annoying gurgling sound whenever my ignition is on? In fact, it is there when I switch on and carries on for some time after I switch off completely?

Regards,
Ray

 

Always leave things as stock as possible, the old parts for the next guy.

Have your reader with you, to see what the real temperature is as you try things out.

Hope your noise goes away, and the temperature a steady reading

 

A very unusual fault!

I may not be correct but I believe that the aux pump is mainly for the heater so

maybe try pulling the fuse for the pump if it has it's own fuse and see if that kills the noises.

If you can't pull the fuse you could just disconnect the pump wiring.

Check that the coolant temp is still the same when driving.

Maybe the first thing you could do is to clamp the flow and return hoses under the bonnet

and see if that affects the noises.

You could also (with the engine off) apply 12v to the aux pump and see if that causes the noises.

 

Why pull the fuse?
It would just cycle a bit more coolant wouldn't it?

 

Let me know how this turns out, if you go ahead with it. I'm also getting a noise behind the vents with the clock, somewhere between a grinding and a gurgling, as well as the smell with the heater on. My next plan was to change the o-rings on the coolant pipes, as otherwise it works as it should & makes plenty of heat.

 

Attached video with sound coming from Air Registers; you may need to turn your volume right up, iPhones are crap sound recorders! Also, don't know why pics have turned on their side when converted from iPhone format to AVI for the site requirements?
Ignore the louder 'clicks'...That's just me moving my 'phone closer to the vent.
Listen right at end...There is a sound like one of the shutters moving? The actual noise in my car is much louder! Does anyone know of a better sound recorder for iPhone, please?
This is with a warmed up engine, ignition off. If I switch on the ignition with a cold engine, no sounds? So heat must be playing some part?
I have NO DTC's flagged up by the Air Conditioning Control Module (ACC/M) which has NOT received any error message from the Heater Matrix Sensor

 

UPDATE: I double-checked and this morning I had the noise with a cold engine? It is much louder in the car than is heard on the iPhone video; I do not know how to get a better recording that might allow someone to help me identify the problem?

What is puzzling me is that given the Heater Pump does not function below 30 degrees C and the Heater Valves are closed below 30 degrees C, how can a backflush with cold water possibly succeed? Surely the closed valves will prevent the cold water from reaching the heater matrix? (PLEASE SEE ATTACHED)

 

EsRay:

I'm pretty confident that your noise has nothing to do with liquid in the heater core. It's the sound of a failed or failing blend door MOTOR. My car has the same issue which I am in the process of trying to solve. The motors are all replaceable from the foot wells. The repair manual has instructions for replacing each one. Use a mechanics stethoscope to find the failed motor and then look for that exact part number on ebay. There are 3 motors on each side of the air handler that control 5 blend doors on each side through a series of linkages and cams. I believe there are 4 different versions of the motors so be sure you get a replacement with the exact matching number printed on it.

I learned all this by purchasing an entire air handling box on ebay. Honestly I'm still trying to figure out what all the motors and doors do exactly. It's incredibly complicated!

Good Luck
Jeff

 

Thank you for your post JCalhoun.
Funny thing is, I had just decided that I was so unsure about the Heater Matrix being the problem and had resolved to remove my Glove Box to enable me to try to isolate exactly where the noise was coming from!
I had already printed the Glove Compartment - Removal, pages from the manual today, before receiving your timely post!
'Incredibly complicated' sounds like the epitome of Jaguar motor cars!

 

There are no valves in the x350 heating system.

All the info you posted refers to an S type.

You could scan the Jag for codes.

My son has a VW Passat with noises in the dash

and when he scanned it it came up with a code for a faulty

blend door motor!

 

OOPS! Thanks Meirion1. Saw the heading XJ/XK Climate Control System and assumed that was what I was looking at?
I have done a scan (as previously mentioned) and found no codes.

 

JCalhoun

" I believe there are 4 different versions of the motors so be sure you get a replacement with the exact matching number printed on it."

I had assumed that all the motors are the same and it's just the white plastic tracks that are different.

please confirm that I am wrong. lol

 

Meirion: I don't know if the ACTUAL motor is the same but there are several different part numbers printed on the motor enclosures. I do know that at least some of them appear physically different. In some cases the same motor # is used on both L and R side controls but in different places and in some cases the motors are only used only once so there are a total of 4 different types. I think there is a 7th one that controls the recirc door.

Left side motor #s (from highest to lowest) Right side motor#s
063700-8540 063700-8530
063700-8530 063700-8540
063700-8630 063800-0030


Jeff