Recently had the thermostat housing and expansion tank replaced. I had been loosing coolant for a while. Heater was hot.

Garage did the work, said they struggled to bleed the system, but car eventually return.

Heater is not heating. Temperature gauge when warmed up, 70mph, bang in the middle.

I tried bleeding the system myself; topping the expansion tank to full, setting heater to max. Car on sloping drive, nose up. But all that comes out of the bleed screw is coolant.

What might the issue be? All correct spec coolant. New rad and waterpump a couple of years ago via a Jag specialist. Jag specialist was unable to diagnose my leak, which a non-specialist found to be related to a cracked plastic housing.

 

Why were the water pump, radiator, expansion tank and thermostat housing replaced? Were any of those actually leaking coolant? Take the Jaguar to a reputable auto service center, and not the Jaguar dealer or Garage. Heck, I wouldn't trust those fly by night Jaguar mechanics to change my engine oil.

 

Radiator let go during pressure testing. Pretty sure that was a coolant leak.
Weep from waterpump
Thermostat housing cracked. Very common issue on X350s. It leads to a loss of coolant while the car is warming up, but the coolant loss stops when the engine is hot (the crack closes up). Hence a few quick trips to Tesco results in low coolant, but a long 2 hour drive results in hardly any loss. It can befuddle some mechanics because the leak might not sure when pressure testing a hot engine. ie the garage really needs to keep it for a few days for proper diagnosis. The initial thoughts was the common cracking of the expansion tank. When replacing the thermostat, you are paying for the removal and refitment of the expansion tank. Labour is about £90 per hour. The tank was less than £90 from jaguar, so a cheap part. The thermostat housing was much much more, and I was lucky, because it appears Jaguar has discontinued the part, but a 3rd party reseller had some genuine assemblies in stock, for a price.
The actual expansion tank is a cheap part from Jaguar, and was a precautionary replacement while the thermostat housing was being replaced. The car is nearly 20 years old and 120k miles.

I have never had the car worked on by a Jaguar dealership. The waterpump and radiator were replaced by a well known Jaguar specialist in the Milton Keynes area. jaguar Specialists are not Jaguar dealers. Typically, they are independents with knowledge of JLR and who have acqured the necessary SSTs. Though to be fair, the other Milton Keynes Indie is charging the same price as Jaguar for a brake job, and only offers a grubby old sofa to wait on, and no signs of complimentary coffee and buns.

The thermostat housing and expansion tank was replaced by a trusted garage that I have used for many years. Technically they are generalist, but they also run the most successful MX5 racing team in the UK (my other car is a MX5).

Glad to read of your suggestions of what might be the issue. Oh wait you didn't come up with a suggestion but a bunch of wrong assumptions and irrelevant comment.

So you don't really know why the heater is still cold.

 

core’s busted

really easy job

 

Is the Bosch pump running and if so is it pumping?

 

This thread:

https://www.jaguarforums.com/forum/x...lation-130143/

Suggests 4-5 hours work.

£240 for a new heater core and 4*90= £500, another bloody expensive job on what is increasingly turning out to be a poor car.

How do you diagnose this issue, before I shell out more cash?

 

What is this? What does it do? How do I check if its still pumping? Why do you think this, and not the core? Do you mean the Auxilary Heater Water Pump, which is £357? This is described by some as "making the heater work sooner" rather than not at all.

 

To me bleeding is the problem you got air stuck somewhere.
what I did after the mecanic did not take the time to fill up and bleed correctly or to fill up over pressurized system .
i have a very steep hill in my area . Drove it up slowly to descent again when arrived on top. For four days in a row did that when coming home . No more issues

 

What size is the engine ? The V8 cars have an auxiliary coolant pump, that essentially is there to assist the coolant to go around the heater matrix. The V6 3 litre cars don't have this pump. The heater matrixes are notorious for clogging-up, but the peculiarity is only the driver side is affected at least initially . However, if the auxuliary pump fails then coolant won't go round the heater quickly enough apart from any matrix clogging.
I got the matrix clogged syndrome on the second X350 I ran, actually the later restyled car the X358. It was done at the local main agent for not a huge amount of money, the main cost was the parts. There was the matrix, plus a kit to reassemble it all, but I don't know what that includes. The labour charge was not outrageous and certainly it wasn't 4-5 hours. I think the Jaguar official time for the job is 2-3, but haven't had the car since Jan 2019, so haven't got the original invoice.

So what has to be done ?
- drain off coolant (obviously)
- remove glove box
- remove heater motor and blower assembly
- undo matrix fixings
- remove matrix
then reassemble with new matrix, discarding parts for new ones in the kit. Refill coolant.
Anybody who tells you the whole dash has to come out is telling you lies. Of course, the parts will now cost more as these cars went out of production in 2009.

 

2004 3.5 v8.

 

Yes auxillary pump
Check that it has power and it is running.