Hello All,

Please can have some advice regarding warming up times for an XJR. I have noticed that since having my water pump and thermostat changed, that my car takes significantly longer to reach operating temperature, purely based on the position of the gauge.

My original thermostat used to get the car up to temperature within 3-5 minutes of starting but the new one seems to take about ten minutes with similar ambient temperatures. Once there all seems well.

I understand these cars had a thermostat that enabled quick warm-up to maximise effieciency.

Any help would be most appreciated.

Regards,

Sonny

 

Welcome to the board.

Where was the T Stat sourced from? is it a Jaguar OEM item as this is obviously the culprit. Or the pump isn't performing as well as OEM lower flow rate with take added time for fast warm up.

The old mantra, if it ain't broke don't fix it.

Another tip, fill in your car details for year and model for a more educated answer...

 

Hello Sean B,

Thank you for the reply. To answer your questions, the car is a 2001 XJR, with a steel lined engine.

The only reason both the thermostat and water pump were changed was to ensure that the car had the 4.2 style item with the metal as opposed to plastic impellers. All information I read all suggested that the thermostat should also be changed.

The work was carried out by an Jaguar independant so I will now question them tomorrow regarding the sourcing of the parts.

Regards,

Sonny

 

The UK 2001 had the already uprated waterpump, again with plastic impellers, but white/cream, not black (like on the early AJ26 engined cars, 98/99) so no worries there. It could be that the metal impeller pump isn't moving the fluid at the same rate...