1998 XJ8 coolant warning

[PaulB81]

Hi all

Firstly, apologies if this is a regular question. Search is not working at the moment.

I picked up a 1998 XJ8 today (3.2L), on the way home the coolant warning light came on. The water temperature didnt move a muscle all the way home so it didnt appear to be overheating.

When I got home and once the engine had cooled I opened the bonnet, at the back of the engine bay I found what I *think* is the coolant, opened it, orange fluid right to the top which I gather is correct.

Is there another place I should be looking for coolant or another cause for this?

Thanks all

-Paul

[PaulB81]

NormanD said:

They often get stuck showing low water

The float is in that water tank

Thanks for the quick replies guys.

So just poke my fingers in and fish around for a float ?

[PaulB81]

Tame Technician said:

To stop the coolant false alarm u need to over fill it just a tad, what we used to do back in the day, when I worked at a jag dealer, 1998-2006. Have an assistant hold the engine at 3000 rpm, the coolant level will drop, at this point top it up to max and put the cap on quick.

I will give that a go. Any recommendations on where to get the orange coolant or shall I get some from a main dealer

[PaulB81]

Is it worth using distilled or is that a bit overkill?

[PaulB81]

Jaguar steve said:

The cooland level sensor is under the header tank at the front. Low level indications can also be caused by a poor electrical connection between the sensor and it's plug. Unplug, spray a shot of WD40 and reconnect.

You must not mix different coloured coolant. Buy the proper orange long life coolant from a Jaguar dealer and dilute it 50:50 with either tap or distilled water.

Cooling issues on pre 2000 cars - including actual, not indicated low levels - can be caused by waterpumps loosing efficency. With the engine stone cold open the header tank, start the engine and rev up to 2000-3000 rpm. You should see a reasonable flow of water into the tank. If not you may need a new waterpump now or perhaps headgaskets or even a new engine a little later.

BTW the temperature gauge is not an accurate indication all's well in the cooling system.

Edited by Jaguar steve on Monday 14th May 07:55

Thanks for this. I feel a bit shameful asking this, but where is the header tank at the front. The only coolant related bit I could find in the engine bay is right at the back below the windscreen (or is that what you mean by front). Is the plug mentioned easily accessible or will I need to remove something in order to see it. Hopefully.... its just a sensor type issue!

The tank im looking at in this pic is in top top left of the pic, just above where the duct to the air filter starts. Is this where I should be looking? Incase you hadnt guessed, im a mechanical retard but willing to have a go

Edited by PaulB81 on Monday 14th May 13:09

Edited by PaulB81 on Monday 14th May 13:10