So I decided to drive the 2005 XJ VP down to Florida from Toronto (24 hr drive time - about 2,300 km each way). Car seemed fine at departure. 220,000 km/136,000 mi on it. More my Sunday driver car now, but I like the quiet highway ride it gives as it purrs along at 1,700 RPM all day going 120 km/h on the open road with no traffic, so I take it on long trips.

3 hours after departure (I-90 between Buffalo and Erie) I pull away from a refuel, 3.200 RPM to get up to 120 km/h, and a minute later get a strange array of warnings. First the check engine amber light on the left dial comes on. Then a few seconds later I get a 'restricted performance' message on the center dial with its own amber light. Then 15 seconds later the coolant dial, which was in the normal position, goes (in 2 second elapsed time) to maximum H with an accompanying red warning light. Great, I think. So I pull over to the side of the road and pop the hood with engine running wondering if a suffered a total coolant loss. Outside air temp was -10C/14F. Coolant reservoir is intact and full. Rad is not leaking, hoses seem fine. No dripping from under car and no white smoke. Rad and engine cover are not overly hot to the touch, nor is coolant reservoir overly hot to the touch. I get back in idling car and attempt to accelerate back to highway speed. Car lurches and won't accelerate faster than 2,000 rpm, so takes quite a while to get up to highway speed. Pull off at first exit. Car continues to lurch and refuse to rev beyond 2,000 RPM. Not sure what is wrong. Pop hood again and no obvious signs of a problem. Turn off engine. Turn on engine. Restricted performance message goes out, coolant dial immediately resets to normal reading, check engine light remains on. Decide to continue to first night hotel in Charlotte NC. Car seems OK next morning on cold start and so I complete the next day's 12 hour drive to Florida. Check engine light goes out in SC after a refuel, and car is going fine with no warning lights, until Georgia when check engine light comes back on and stays on, but no issues with restricted performance or coolant temp dial.

In Florida I take car to local garage that services European cars. They scan codes and tell me the sensor in the coolant tank has failed and solution is to replace coolant tank. I don't see how this sensor could cause such havoc as when the float sensor fails it just says 'low coolant' incorrectly and has no bearing on anything. Still, I agree and they replace tank/sensor. They pressure test coolant system and say all is good, and clear the codes. 2 weeks later (car not driven during this time locally) I drive back to Toronto.

On the way back the exact same issue/sequence of events happens again. This time I know a restart will get rid of the lurching and lack of acceleration, and it does. Not happy, but I get back.

Take car in for Jaguar service. Tech agrees with me that coolant level sensor failure in coolant tank could not have caused this condition. Reads codes and says he is getting a P0116 ECM "Engine coolant temperature circuit range/performance problem". I mention that Florida place pressure tested cooling system after replacing coolant tank, did 40-point inspection, and signed off that car was roadworthy to drive back to Toronto and problem was resolved. Toronto tech goes over each part of cooling system. He found "engine cooling fan seized and not rotating at all, causing vehicle to begin to overheat when electric fan air flow is required. Recommend replacing engine cooling fan and engine fan relay." So highway travel at low RPM and freezing outside temp, combined with coolant system otherwise functional was enough to keep engine cool, but idling the car at a gas station or rest stop combined with the higher RPM of accelerating away from that stop to highway speeds caused the sequence of events. Driving at highway speed with warning lights on cooled the engine without the fan, so a restart cleared the restricted performance and high coolant alert as the engine was not overheating at the time of restart. As all the driving was at highway speed plenty of airflow was available. New cooling fan installed, problem resolved. I just wish the Florida place had realized the engine fan had seized up and replaced that rather than do the unnecessary coolant tank replacement and leave me in a situation where I could have been immobilized if I had left the highway and ventured into bumper to bumper urban traffic.

 

So maybe if they had done a 41 point inspection that would have included checking the fan.Sad that knowing you were having a temperature problem that the tech didn't look at the cooling fan.

 

Thank you for sharing.
Obviously the Florida garage is incompetent or didn't do proper checking, just selling you a new tank and sensor and charging manpower...
You're lucky with the smooth highway driving and low temps, may have been much worse...

 

Really hate to hear stories about such incompetent shops. As you mentioned, the reservoir float has nothing to do with any check engine or restricted performance lights. Glad your car is back running well, and since those tanks are so prone to failure at least it wasn't a complete waste of money.

 

Glad the temps were cool enough to keep you from overheating.
Agree the garage should have found the frozen fan.
One needs to do ones own work if at all possible.

 

Curious, where did you source your fan and how much if you don't mind me asking?
I think mine is starting to get too weak for AC.

 

The invoice lists:

C2P16825 - Electric Radiator Cooling Fan: Can$ 961.32
Labour: 2.3 hours: Can$310.50
Had the work done in Toronto, Canada.

Total cost in Can$ was $1,271.82 (that is about US $926.00)

They included a T4N15704 Cooling Fan Motor Relay as well (CAN$ 20.70/US $ 15.)