My (my2000) XJR needed the coolant topping up last week (took 600 ml). I've driven 350 mile to Ireland when the coolant low light came on again, I've topped up again took approx 250 ml. I can't see any leaks around the engine bay but yesterday morning the restricted performance light came on and the engine was very lumpy untill the temperature rose when everything seemed fine. I checked the codes and have P0303, P0306, and P1316 which I then cleared but this morning I had the same starting symtoms again and have just read the same codes. Again the light went out and the car then ran well on a journey of 30 mile, although I now think the exhuast looks a bit steamy (vapour) but then I never paid much attention to it before so I don't know if it's worst than normal.
Can anybody help me with this, I still have 200 mile to drive back home. Any advice is welcome please
Thanks
Stewart

 

While the P0303/0306 are cylinder specific the P1316 adds such things as fuel contamination. The XJR also has two fuel pumps in series for volume and pressure, one may have failed.

Mysterious coolant disappearance is usually a sign of a water pump failing but I had a leak that was a fine mist and just couldn't be seen around a hot engine. Only found it by using a pressure tester on a cold engine.

Sorry I can't be any more specific.

 

I'd suggest head gasket or warped head, but in both the NA and ROW versions, cylinders 3 and 6 are on opposite banks, aren't they?

 

Coolant thermostat housing is prone to cracking and letting coolant out. Wlesh Enterprises Inc do an aluminium replacement. Does it smell of coolant when you raise the bonnet ?

 

I've stopped using the car while I'm here (staying with family), it's about 220 mile to my home and I'm hoping if I drive carefully and watch the temp guage like a hawk I'll get her back okay, then I can go to an independant dealer to have it checked out.
I've looked all 'round the engine I can't see or smell any coolant. When first started it idles a bit rough and the orange light with restricted performance is on, as soon as the temp needle starts rising (couple of mins?) the light goes out and the car runs perfectly.
My dad says theres a lot of dodgey fuel over here and maybe I've got a tank of that!!!
I was really hoping it isn't the head gasket, surely a bit strange both banks would blow at the same time?? I thought the steam level looked the same from both tail pipes, also the pipes are clear when I pull up but after maybe 30 sec it appears although I must say not massive clouds.

 

If it's any consolation, I got back home on a very hot day from holiday in the UK on an 85 degree day with a blown headgasket on my 1980 XJ6 and about the same distance too. I just had to stop every so often, let the engine cool off, top coolant up, and go again.
At one stop you could see our coolant trail into our parking space; that's how bad it was !!

The V8s can blow head gaskets but it's not a common fault as I understand it. One dead ringer for HGF is excessive pressure in the coolant jacket, (from combustion gases), blowing the coolant past the pressure cap, and out of the overflow.

Take plenty of ready-use coolant so you can top-up en-route if you need to, but make sure you at least stop and check every 50 miles.

 

Well I made it back okay, only used 300ml water. I'd arranged to take it to Preston Jag Centre to have the coolant pressure tested but before I got to them (they are very busy) the pipe/gasket let go, lost all the coolant and lots of steam coming from under the supercharger area. The temp guage never moved from the central (normal) position during my 3 mile drive back to my house - hope I'm lucky.
Are there any other independant/good garages in the Preston/Leyland/N.West area? Preston jag arranged twice to come and collect the car but twice haven't turned up, they do say they are very busy - is that a sign of how unreliable Jaguars are? ha.ha!!
Any more ideas on my problem are welcome
Thanks
Stewart

 

My low coolant light came on a month or so ago. I checked level and it read fine but I did smell coolant when I opened the hood but did not see any leaks and nothing on my garage floor.

A couple of day later after driving home from golf, I parked the car in the garage and while walking into the house I heard a gush of water leaking from my car. Upon inspection I found that the upper radiator hose had come completely off the engine. I inspected it and it looked fine so I re-connected it, tightened it down and re-filled with coolant.

No issues since - no warning light, no smell of coolant and no overheating. All I can think is that the hose had somehow loosened a bit and was letting a small amount of coolant to escape (enough to smell but not see). At some point the pressure got too great and it just blew the thing off the engine.

Joe
98 VDP

 

Well I've given up on Preston Jag Centre (shame as I had hoped to start a good relationship for future servicing/repairs etc), third time they said they were coming for the car and again no show!!!
It's booked in to my local garage who normally does my MOTs for tomorrow morning, they are confident that they can tackle anything on a Jaguar.
I had another good look around the engine and I can see coolant puddles under the supercharger, I can also just about make out a pipe in there that looks wet, hopefully it's not serious after all.

 

uh oh, sounds like it may be a leak on that coolant line that runs under the SC. See whiteSTRs post in the S-type section, pictures are there of the aforementioned line.

 

Gonna be expensive!

 

On the bright side, coolant can travel under the supercharger from several places. Mine did it with a small split in the bypass hose, which was not easy to spot initially. It was a $20.00 fix. I was mopping up coolant under the back of the S/C using a wooden chopstick with a cotton ball taped on, trying to find out where it was coming from. (it was leaking up front, pooling at the back) A small leak in the thin breather tube that runs along the charge air cooler from the reservoir to radiator could result in coolant under the supercharger too. The restricted performance issue is a bit of a concern, I guess.

The best of luck with it.

 

Mechanic has told me it was one of the hoses under the supercharger, it is very soft where it has split so I've asked him to replace both while he has it stripped down. Provided the Jaguar dealer has them in I'll have the car back tomorrow, don't know the cost yet but seeing as I was preparing myself for the worst (head gaskets) I'll not be too bothered. I'll be glad to get her back, it has been pretty cold on the motorbike these mornings!!

 

Very wise my friend!

Please let us know the final bill..for others to wow at.

+ = brrrrr!