After a brief drive in my 2003 XK8 4.2 today, the low engine coolant message came up! After a few minutes the message went out but naturally I'm concerned and want to get it checked out.

My big problem is I've never been able to get the coolant cap off in my ownership of the car! Is there anyway of somehow making it easier to undo?

The inspection report that came with the car when I bought it last year said the coolant level was fine and I've been driving the car without any warnings until today.

I guess my best plan of action is to try and get the cap off to see if the level is low or if its a faulty sensor or float. If I can't get it off myself, there is a garage I know less than 2 miles away.

I wouldn't imagine it's anything too serious like a head gasket as the engine always sounds great and the oil cap was very clean when I last checked it. The car has been serviced every year at Jaguar specialists, even if it only covered less than 1000 miles a year.
Are either of these the correct coolant?

https://www.halfords.com/motoring/en...ODcwNS4wLjAuMA..

https://www.halfords.com/motoring/en...ODgzOS4wLjAuMA..

Greatly appreciate any advice - many thanks in advance

 

The o-ring swells up and makes the cap hard to take off even when unscrewed fully. I’ve replaced a couple of caps thinking they were warped. Then I discovered that replacing the O-ring was a better fix to get the cap to release easier.

to get the cap started I often have to use a channel-lock type pliers opened up fully. Use just light pressure on the caps notches and turn the pliers and it will get unstuck.

good luck !

Z

PS I use the orange coolant on my 2002 XKR. it should say on the expansion tank what fluid to use.

 

Surely you can remove the remote header tank cap off with a large adjustable spanner or a strap wrench or similar? Once you have removed it, smear silicone grease around that cap, or a new one, and it will never jam again. I must admit to being somewhat surprised by this thread as, speaking personally, not having access to the coolant header tank would verge on rendering the car unusable.

Richard

 

Many thanks for all the replies, much appreciated. Weirdly, I tried the cap first thing this morning and it came off easily. The level is pretty low but it's not empty, there's still some coolant in there and it looks healthy as far as I can tell, no contamination or burning as far as I can tell. As I say, I haven't checked the level until today since buying the car last year so I don't know if it dropped dramatically yesterday or whether its always been a bit low! How much coolant will I need? To be on the safe side, I'll buy enough to fill the tank so does anyone know the tank's capacity? After topping up, I'll run the car and see if the level stays up. I can't see any obvious leaks but I'm no expert! Thanks again

 

Just to add to the above, am I right in thinking I should fill the coolant up to the neck of the tank?

I've read a few things online about only filling the tank half way but I've seen a YouTube video which says to fill it up completely which sounds the correct thing to do.

 

Yes, that's correct.

I always back the cap off a quarter-turn from tight, since it's the O ring that makes the seal.

 

You'll need to buy a litre of antifreeze as a minimum and that should suffice to fill the header tank. However, if the header tank is that low the atmospheric expansion tank will be empty and that is the tank that needs to be around half full, although that is not critical.

Fill the header tank to the bottom of the neck and then drive the car. When the engine is cool, check the level again and it will have gone down. Fill it to the bottom of the neck again and repeat this process until, when you remove the cap, the level is still up to the neck. This means that you now have sufficient coolant in the expansion tank (it's behind the righthand side wheel arch liner) to keep the remote header tank filled up.

Richard

 

Many thanks Richard, can I just confirm that the coolant / water mixture ratio is 50/50 and is it necessary to use ionised water or is normal tap water ok?

Thanks again

 

It's good to see you taking this on.

I keep a strap wrench to get the cap off without marring the plastic cap: https://www.harborfreight.com/rubber...ece-69373.html

If you are losing coolant, it's going somewhere. Do you ever smell warm maple syrup? That's what coolant leak smells like.
If you're lucky, it's a loose exterior hose or hose clamp. If you're not so lucky, it's a failing water pump or octopus hose.

This is how I approached a similar situation: https://www.jaguarforums.com/forum/x...3/#post2304896

Using this very useful tool: https://www.harborfreight.com/radiat...kit-63862.html



X100 2001 XKR pressure testing coolant system

 

No problem. If you're bought concentrated coolant rather than pre-mixed, the 50:50 dilution is correct. I would definitely not use tap water if your water is hard and would only use soft tap water in an emergency. As you suggest, de-ionised or distilled water are the way to go. If you don't have either of those available, then the condensate from the tank of a tumble dryer is also suitable.

Richard

 

Easiest way is to purchase a jug of pre-mixed 50/50 coolant (the correct formula, of course)....

 

Many thanks again for all the replies - funnily enough, I've just found a bottle of pre-mixed 50/50 OAT coolant from Halfords that I bought for my diesel XF last year but didn't end up needing.

As far as I can tell, this coolant is the same as the correct Halfords one I mention in my first post above apart from it is pre-mixed 50/50 rather than concentrated.

Can I just double check that this pre-mixed coolant will be ok for my 2003 XK8? I've attached a couple of photos.

 

Yes, that's the same stuff as the concentrate .... it's just diluted already.

Richard

 

That's excellent, many thanks Richard, I'll top up the coolant with the diluted one tomorrow.

Sorry to make such a fuss over such a simple job but I'm a bit paranoid about adding the wrong stuff! I keep hearing that it has to be Ford spec M97B44-D but in a nutshell, as long as it's OAT and red/orange it should be fine.

 

The only disadvantage with using the red/orange stuff is that if the stuff already in there is green, blue or yellow rather than clear, you usually end up with a dirty brown colour which looks ugly, particularly if you have a translucent tank. which we don't. The only solution to this is to drain and flush out all the old coolant and refill with the new colour. This should be done every 8 years or so anyway so, if you don't know when this was last done on your car, it would be worth doing it once you have ascertained that there are no leaks.

Richard

 

The orange is the right coolant. But as mentioned, you might want to use the type as what is already in the system. Mixing to distant types of coolant can result in a plugged up radiator.

the current coolant could be anything, but hopefully it’s the proper coolant already.

 

Thanks again, the current coolant looks orange so I'm sure that the Halfords OAT will be fine.