Hi guys, I have been trawling through your great site for the last few days since acquiring a 1999 XJR supercharged.

I bought it with an overheating issue which I hope is going to be a non-expensive fix!
If I drive the car steady without using the supercharger it appears to drive fine, the temp gauge needle goes to the middle & stays there. However, if I stick my foot down and boot it for even a few seconds (all I've managed so far) soon after the needle rises to the top of the temp gauge and I can see a trail of fluid behind me on the left side of the car.

been out in the car today, took it for a gentle 3 mile run and its started leaking coolant from the ovelflow tank towards the end, so it appears its doing it all the time now?

On opening the bonnet I can clearly see the coolant coming out of the over flow tank inside the front left wing, it's pouring out of the small round opening and there does not appear to be any cracks or issues with the tank.

The water pump & thermostat have just been replaced to try and cure it, but no success as yet. I have also swapped over the expansion tank cap for the one from my x-type as they are the same and I know that one to be good.

I have noticed the bleed pipe going to the top of the radiator on the left side is leaking slightly at the join and if I squeeze the radiator hose on the left which goes to the supercharger I can hear air escaping.

Thanks for taking the time to read my thread and I look forward to getting all and any feedback.

 

Hi guys, I have been trawling through your great site for the last few days since acquiring a 1999 XJR supercharged.

I bought it with an overheating issue which I hope is going to be a non-expensive fix!
If I drive the car steady without using the supercharger it appears to drive fine, the temp gauge needle goes to the middle & stays there. However, if I stick my foot down and boot it for even a few seconds (all I've managed so far) soon after the needle rises to the top of the temp gauge and I can see a trail of fluid behind me on the left side of the car.

On opening the bonnet I can clearly see the coolant coming out of the over flow tank inside the front left wing, it's pouring out of the small round opening and there does not appear to be any cracks or issues with the tank.

The water pump & thermostat have just been replaced to try and cure it, but no success as yet. I have also swapped over the expansion tank cap for the one from my x-type as they are the same and I know that one to be good.

I have noticed the bleed pipe going to the top of the radiator on the left side is leaking slightly at the join and if I squeeze the radiator hose on the left which goes to the supercharger I can hear air escaping.

The engine has had a sniff test done to check for head gasket failure which came back fine. It is a green tagged jaguar replacement engine being recalled back in 2003 under warranty.

Thanks for taking the time to read my thread and I look forward to getting all and any feedback.

 

The XJR has a rather extensive system to remove air from the cooling circuit -- While its always possible that you had some initial trapped air .....what you describe now sounds like a bad head gasket pressurizing -- actually over-pressurizing the system and pushing fluid to the secondary tank.

The best thing to do is have the system pressure tested so you know what is wrong and you don't do any additional damage --- like coolant in the oil.

The temp gauge is electric and designed to stay in the normal area for a wide temp range -- It's really no different than an idiot light -- when it enters the upper areas the engine is overheating.

 

Thanks for the reply yeldogt, I take it doing a pressure test is more accurate than the sniff test already carried out?

I have been checking the oil daily since ownership and there is no water in the system as yet, so maybe get it to the garage next and do the pressure test I guess.

Thanks again for your input.

 

When you turn the ignition on can you hear the intercooler water pump at the left front of the engine compartment running? It's tucked down below the front of the air filter.

The location may be wrong, that's on the XKR, but check there first.

 

I have not tried that as yet, i will certainly give it a go though thanks. I take it if it's not running this would cause a similar issue.
Do I need to fire the engine or just put on the ignition?

 

Also just to say it runs very sweet and has no misfire etc. I have today ordered a code reader to plug in and carry out some checks just in case there's something in the memory bank that can shed any light.

 

The pressure test will first show if the system can hold pressure -- if not then it is leaking someplace. Often -- the leak will show up externally.

The Jaguar V8 engine does not like to overheat .. even once can cause problems. The early cars like yours have a few issues. Both the water pump vanes and the thermostat caused problems -- as well as three different coolant specification changes on the earliest cars.

With an early car much could have been done to the system -- with more then one opportunity to not correctly flush and fill the system with the correct fluid.

What did the system look like when you replaced the thermostat. Since it predates the thermostat -- it is most likely not that .. but many aftermarket thermostats are junk.

I have never heard of a failed SC pump causing an overheating condition -- it would surprise me if that was the cause.

Many of the older cars suffer from incorrect coolant -- and corrosion.

 

The guy I bought it from replaced the thermostat & waterpump so I cannot vouch for their condition.

Just as some more on the background of the car, it was taken in by the po on a px deal against his rolls Royce. The owner of the jag drove it over 80 miles from his house to do the deal, and just before arriving it overheated. He was honest about what happened and so the deal still went ahead. the new owner then went about doing some repairs to try and fix, including the water pump, thermostat, the big hose by the thermostat was split and replaced and new coolant added and bled by removing a pipe from the supercharger until it ran out (not sure if that's correct?)
Never made much difference so he had moved it on, which is where I came in to owning it.

 

Take a look at the overflow hoses (hard plastic): if they are misrouted, you will get overheating and blow coolant. The hose going to the radiator should be to the left as you were looking forward, the hose to the overflow in the left fender well, should be to the right of the first hose. Said another way, they cross over each other as they come out of the coolant reservoir. Often, mechanics will misroute them when they change thermostats and water pumps.

 

Thanks for that, I have checked that and the hoses are as you describe and the right way round.

 

Considering it's 16 years old now, someone may have mixed coolant types and they coagulated in the radiator. It's happened before. I believe there are ways to check the circulation in the rad with a laser thermometer, or other simpler ways.

 

Thanks for all the input guys, I'm going to get it into my local garage this week and see if they can make any sense of it. Hopefully I'll be able to update soon with the results.

 

been out in the car today, took it for a gentle 3 mile run and its started leaking coolant from the ovelflow tank towards the end, so it appears its doing it all the time now and not just under load when i stick my foot into the carpets?

 

my 1999 xj8 just recently started losing radiator fluid at a fast drip. it is dripping from the middle of the engine to the ground. Not sure dripping from where. It has not overheated and sitting in garage waiting for me to take next steps. I can get it to a mechanic and i suppose it could be hoses, water pump, coagulated fluid....anything else I can be checking for? Would there be more obvious signs if it was the water pump?

 

Update for you all:

sadly it appears the head gasket has blown!! so the worst scenario has come to fruition, so i have taken the quick step to sell it back on again with this issue as its beyond my budget and knowledge base to repair.

I cant tell you all how gutted i am, but it is what it is, if i could afford the repair on top of what i just bought it for i would be all over it, but it just makes it economical for me.

To that end i have just picked up a 4.2 s type to bomb about in, lets see how this one goes!

thanks again for all of your help and comments.