Got a low coolant warning accelerating up a steepish on-ramp. Hmm, better look at that at the next place with services. Pressed the OK button and the triangle went away about two minutes later. Knowing Jaguars' propensity to throwing random codes (I used to have a 2008 XKR) I wasn't too bothered.

Never made it to the next services. Few miles up the road the heater suddenly went cold and the motor starting pinging badly. Shoulder and off PDQ. Steam was coming out of the HVAC inlet vents just below the windshield. WTH??? Never smelled a thing inside the car

Temperature gauge never moved. This was on I-40 in N Arizona. Thank goodness my fiance was with me as my AT&T phone had no service, but her Verizon phone did. AAA trucked me back to Vegas. Of course, it was well over my 100 miles free towing so my CC took a hit.

What do you all think, waterpump or a hose near the heater matrix let go. The steam hauling out of the inlet vents was "interesting".

 

It could very well be the water pump, or a failed hose.

What is the vehicle's MY and what engine is fitted?

 

My bad.

2012 XJ SWB 5.0 naturally aspirated.

 

Has the water pump been replaced with the later version?

Is the vehicle still under the factory warranty?

 

It's out of factory cover as far as I can tell. Four years, isn't it?

I've owned the car since February, and I've never had the water pump replaced. It only has 43k miles on the clock, so I doubt the original owner had the pump changed.

 

The water pump in my 2013 XJ 5.0L SC failed at under 30K miles and was replaced under warranty. It's a known defect.

 

Mine had the water pump changed at 41,xxx miles after mostly highway driving. That kind of driving will extend the time until it fails it would seem. Most of the cars I've seen fail at 36,xxx miles.

 

Just had my 2013 with 26,600 miles replaced under waranty.

 

The water pump is the most likely culprit as a cause of coolant loss and should be inspected every time the vehicle is serviced.

Hopefully there is no other damage to the engine, but there have been several instances where a failed water pump on the 5.0 litre unit caused catastrophic damage to occur.

 

I've learned that if you get low coolant level warning you need to stop very soon and at the very least fill the coolant with water (preferably distilled water) and then drive or get the car towed to a dealer or repair shop of your choosing. The fact that you drove it after the warning without trying to remedy the issue quickly and that the engine started pinging and the heater lost coolant to heat the car would indicate you ran just about out of coolant. The added fact that the temp gauge did not register hot is because the coolant temperature sensor has to be immersed in coolant to register the temperature and most temp sensors are placed fairly high in the engine. I fear that you may have caused damage to the engine. Hope I'm wrong. BTW I went through 3 water pumps till they finally got it right with the pump made in Italy. Also there are some pipes that fail especially the "Y" pipe near the water pump. I recommend that going to a dealer and letting them replace all the questionable hoses and piped behind the supercharger is what I have learned is the best way. Of course my recommendation is that if you have a good dealer with very experienced techs.

 

Mine quit at 35,000 miles, so you're right on the money.

 

My service guy here in Vegas also pointed the finger at a hose in the engine V. I assume that is one of the parts to which you refer. My guy is also going to do a block check on completion of the fix.

As for continuing to drive the car, I have a small excuse. Where things went bad is in a 50+ mile gap with no services on I-40 in Northern Arizona. That kind of geography tends to give you "press-on-itis". See picture.

As for the temperature gauge not changing, I can't help thinking that Jaguar (and just about everybody else) has drastically over damped the temperature gauge response. Their excuse is probably something like "to maintain customer satisfaction" or some other form of weasel words. I had old cars in the UK go FUBAR with blown rads and water pumps, and the temp gauge always did SOMETHING. Had the gauge dramatically DROPPED when the coolant went away I would have been convinced to stop immediately. With all the BS codes vehicles throw these days, one intermittent indication doesn't get me that excited. Heck, just disconnecting the battery on my SUV will cause it to throw a code until the stability system relearns which way is up.

 

Have the person working on the vehicle perform a compression test of each cylinder.

 

So the last time I developed a coolant leak I was in Charlotte NC, and had Jaguar flatbed the car to my dealer in Atlanta. The pump had not failed but an outlet pipe had failed. I had all the parts done that were covered under my extended warranty that I bought from the dealer and at the recommendation of my Tech, had several other hoses and pipes replaced at my cost, but there was no additional labor costs. I've attached the invoices so all my have the part numbers. You may find the parts for less, but these are what my dealer charges.