Hi, I am new in this forum I live in Uk , I have Jaguar xj X351 2012 , I am experiencing problem on my car when I drive the car 70 mph on motor way the engine over heat when I slow down to 50mph become normal is there any help I am in Uk london area , please help I use the car for work. Thank you for your help in advance

 

Overheating on these cars is very dangerous for the engine, please take immediate action or you might need a new engine. In any overheating case, the first thing to check is coolant level.

Normally, faster you go, less issues with heat there are, as increased airflow at speed better cools engine. As such, my guess is that your issue is continuous operation and not speed.

Is there any unusual smoke that comes out of exhaust under acceleration?

 

Thanks for reply, I didn't notice any smoke coming out I drove it yesterday with constant speed 40 mph no heating going up only when I drive 70 mph

 

Have you checked your oil level? At sustained high speeds oil tends to get stuck at the top of the engine. With a low level this could cause issues.

 

You should stop driving your XJ before you cause catastrophic damage to the engine. Water pump failure is a known defect of the 5.0L engine. If the hot engine warning light came on you have a problem that must be checked as a soon as possible by a competent Jaguar mechanic if you're not able to do so yourself.

 

Thank you, I will do that the problem with the car is unusual when I am in speed 70mph gets hot when 50 mph and less will be normal even in stationary is normal