coolant level warning

[Tonyinmeva]

Hi all, I have a 1998 XK 8 my coolant level warning came on today about 1 mile from home so I carried on home and put the car in the garage.
Thought i,ll check the level when it cools down...as I walked past the car I could hear a tapping or dripping sound coming from inside the drivers
side wheel arch. can someone explain what this is and how it works ....it must be some sort of water collection system ????
thanks Tony

[mike020150]

There shouldn't be any cooling system component under the offside wing. The overflow bottle is located on the nearside. You will need to do a little more investigation! Mike.

[Astromorg]

Sorry mike, but the X100 coolant overflow is in the offside wheel arch, There shouldn't normally be any dripping sounds as the pipe from the header tank should terminate below the water level in the overflow tank, so that it can suck the overflow back when the system cools down. The level in the header tank should be to the bottom of the filler neck.

If despite filling up, the level continues to fall unreasonably quickly, then you have either a leak, a faulty header tank pressure cap or, if the level stays OK but you get a warning light, then the float switch may be faulty.

The leak could, of course, be from anywhere in the system, but splits in the header tank that are only visible under pressure are not unusual.

Finally, avoid getting caught with an overheating engine. These engines are highly susceptible to permanent damage when that happens.

[Tonyinmeva]

Thank you for your replies, now the bad news ! I did manage to fill the system and the dripping sound stopped. So I went out for a spin not once
has the temp gauge moved above normal ( half way )even when I had a low level warning. I did about 10 miles and came home ,lifted the bonnet whilst the engine was running to check everything and felt the top hose it was hot but not excessive but it was rock solid as if under high pressure. Then I noticed steam coming from the exhaust pipe on the passenger side !!. I,m assuming I have a blown head gasket.
Tony

[mike020150]

Apologies for a bad memory. Astromorg is right. contrary to previous Jaguar practice, Jaguar relocated the overflow tank on this model to the RH wing despite leaving the header tank on the left hand side. Unfortunately, the temperature gauges on these cars are no more than ornaments designed to register in the middle of the range with little movement until there's a dramatic change in temperature. By that time, it's usually too late to save an engine from damage! Good luck with the repair which does sound like a head gasket. Mike.

[Tonyinmeva]

Hi Mike , one other thing I noticed my cooling fans never seemed to come on , is there a way of testing these ?
thanks again Tony

[mike020150]

The fans have three operational modes, slow, fast and off. These modes are dependent upon temperature and aircon pressures and the appropriate modes are invoked by the engine ECU. Generally, the fans are fairly unobtrusive and unless you make an effort to listen for them, you tend not to notice them. Turning the aircon to max cold should bring them into play. Otherwise, without Jaguar diagnostics, testing the system in would be limited to: checking wiring continuity; testing that the temperature sensor in the coolant outlet pipe is giving sensible-looking resistance readings (it's a negative coefficient sensor) with varying temperatures; possibly trying a separate 12volt feed directly to the fan motors after disconnecting them from the wiring loom. Mike.

[Astromorg]

As Mike says, testing the fans with a temporary power arrangement is feasible. Fortunately the early XK8s had a simple relay control module that can be disconnected from the fans and allow the fans to be checked quite easily.

It might be prudent to check the fuses first; F12 and F14, both 30A in the Engine Compartment Fuse Box and F12, 10A in the Engine Management Fuse Box (in the firewall box on the near side)

The way in which the fans are wired is that there is a direct 12v battery supply to the right hand fan (Brown/Light Green wire) and a Ground wire directly from the left hand fan to Ground (Black wire). There are then an Orange/Green wire from the right hand fan to the fan module and an Orange/Yellow wire from the left hand fan also to the fan module.

Follow the wiring back to the fan module, on the left hand, side near the horn

At the fan module, disconnect the Black multi-wire connector and using a jumper lead (of at least the same gauge as the other wires) connect the pin on the Orange/Green wire to the pin on the Orange/Yellow wire. (No ignition required) Both fans should then run together.

After that, next are the two relays in the fan module, but I don't know if that module is sealed or openable. Looks like it should open from the diagrams. Let us know how you get on and we can expand as required!

[Tonyinmeva]

Thanks for all that , looks like i,ve got my work cut out. Looking to the future ...once i,m back on the road would it be an idea to look at fitting a temp gauge that actually gives a realistic reading. Has anyone done that ?
Tony

[Astromorg]

Yes, I have. You need to visit this website

www.thejagwrangler.com

and check out his RealGauge kit.
He's a Jaguar fanatic and his products are of outstanding quality. Add to that his fitting instructions that cover every last detail.