So my wife is driving her '02 JXR and the check engine and low coolant light come on.
She didn't think anything of it and continued to drive.

Then "smoke" smoke started to come out from under the hood.

Lights weren't enough of a warning she just had to wait for the smoke, and well she was almost home so...

Well the smoke turned out to be steam, I think from the water pump. I don't see the leak but it is coming from the front of the engine.

The part should be in tomorrow and I'm going to start tearing it down in the morning.

Are there any tips tricks or pitfalls I should know about?

 

Hey there pingj....sorry to hear about your troubles
C'mon guys, help a brother out

You could also try sending email to ken@britishparts on this forum and possibly also asking the question in the general tech help section......you may get better luck there.

Good luck bud

 

Thanks Jim. I'll give him a shout.

Butch

 

So you're replacing the water pump ? If so, it's very easy, at least it was on my non-supercharged 4.0. I would advise you to replace the thermostat while you are at it. It's easier to do them both at once than separately. Of course, you should make sure no hoses are shot and nothing is leaking.

 

...and we'll keep our fingers and toes crossed that the engine didn't suffer any internal damage from the overheating. I'd change the oil too, if it got hot, it may have broken down prematurely.

Please remind your wife that it would be cheaper in the long run to take a cab or call you from the side of the road (or convenience store) next time.

 

Thanks everybody. Doing the oil change tommorow. I wanted to make sure there were no other problems first.

The water pump was easy, so easy I kept thinking something else was going to go wrong.

My wife started to take it to work today and the low coolant warning came on again. I topped it off and took it out had no problems. Going to check it again after it cools down from taking it home from work. Still concerned there is a leak some where.

Should have thought to replace the thermostat while I had the front torn down, but was too focused ont he water pump.

Should I be concerned about the block and heads? It did get hot but didn't run dry of coolant.

 

So I spent the day doing maintenance on the car. Oil change after overheatingl, coolant flush and refill after the waterpump replacement.

I even had time to change the fuel filter (which was a bitch) and check all the other fluids and filter.

Now I'm still chasing a P1646 code. Any ideas? I have replaced the relay for the S/C fuel pump, checked the fuses and basic wiring check. I still can't clear the code.

 

P1646 Linear O2 Sensor Control Chip (Bank 1)

I had this (and P1647) on Misty ('99 Sovereign XJ8LWB) and it was the upstream O2 sensors (sensor heater failure). It looks like the codes are the same for the XJR. Sounds like you have a toasted O2 sensor on bank 1 (not sure where you are located but IIRC is the driver side in UK so passenger side in US but do check).

I had to replace both of mine - the ECM monitors the sensor heater circuits and if faulty ignores the sensor outputs so the engine never gets into proper 'closed loop' fuel system mode.

If you can get at them (not as easy on the XJR I suspect, I haven't looked yet on my XJR 100) you can swap the connectors over to see if the P1646 changes to a P1647.

BTW you can clear the codes all you want - they will just come back. HTH.

Jim

 

Good advice.

 

This is a prime example of real life(here) of what not to ever ever do. I have replaced 3 engines this year alone for people driving their cars after loosing coolant and or overheating. Get it hot enough and the exhaust seats fall out of the head trashing valves, heads and many times pistons too. Many thousands spent to replace and engine is never cheaper that waiting for a wrecker. Or the cost of any hose or cooling system components. it was 1 man and 2 women. The guy had extended warranty and said well "theyll cover the engine" They covered his thermostat, and the coolant, The engine was all his to pay for since he didnt pull over and kept driving.
Oh and replace the 02 sensor, the heater circuit is failed

 

Brutal, I bet you have more than a few stories like that! If only you had the time...perhaps you should keep some memoirs and publish when you retire. lol

 

Thanks for the advice all. It's not that I'm doubting the O2 Sensor, but why would AllData call the P1646 as a fuel pump relay?

Also just to clarify the P1646 would be the passenger side up stream of the CAT.

 

Oh and I just have to say, I just put new tires on the car and it drives like a new car.

 

From bba-reman.com

Fuel pump – P1646
Model:
Jaguar XJ 1995
Complaint:
The fault code P1646 is likely to be set due to a relay fault in fuel pump No. 2.

Don't know about AllData but it looks like perhaps from an older code set. Your '02 XJR is closer to my '99 Sovereign V8 than a '95 XJ and my P1646/7 were definitely O2 sensors. If in doubt, switch the plugs to see if you get a P1647. If you do there is your proof. Definitely upstream, if you drive on the right then yes, passenger side.

Merry Christmas!

Jim