98 XKR heating problems

After getting the car out of storage what with COVID and putting it away for winter l notice that the heater is erratic.
It takes a long time to barely warm up and then the heat yoyo’s. It is warm for a while and then it goes cold. After a while it warms up again, (not hot) and then goes cold again.
Strange thing is that the passenger dashboard air vent blows warmer than the drivers side when it does warm up.
I have checked the coolant levels and they are correct.

Any ideas?


Does the heater circuit have a circulation pump in it? My X300 (or XJ40) had one and when it died I had no heat.

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I believe so, looking at YouTube…
But l wouldn’t know where to start looking or how to check?


On my XJ40 (or X 300, I can’t remember now) the hoses were on the left (drivers) side. (this is totally from memory) Bolted to the fender on top was a control valve; under it was the circulating pump. Follow the hoses back from the heater box. Hope that is some help. For an illustration of what it looks like, go on the Jaguar parts website or one of the supplier web sites. I find the exploded diagrams on those very helpful.


Thanks for the precise directions. I will have a look see.


I’m basing this totally on memory from several years ago of a different model. I’ve found it very helpful to go on one of the Jaguar parts websites like SNG to download exploded diagrams. Also try tracing the hoses coming out of the heater box.

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Did this job a couple of years ago. Here are a couple of research sources for you. Not an easy job, but doable. If you are a DIY type, you can rebuild the pump with new brushes ( the common issue). It could also be the heater valve, or a clogged heater core, but those are less likely.


My experience on my XJ40 was a lot easier as the pump was more accessible.

Thanks Mike

l take it you mean the circulating pump under the reservoir?


Correct. Heater pump under the coolant reservoir.

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Let us know how things worked out. It helps others with similar problems.

Not had time to work on it yet, but will do .