I've just been out for a drive in the Z and noticed my water temp gauge jumping between 85 and 105Deg and the cabin heater was acting intermittently in time with it

 

ie

temp 105 - heater not working

temp 85 - heater working

 

Where is the water resevoir and is there anything else I should be checking?

 

 

 

Thank you

Check the water in the rad mate. Looking at the car it's at the front on the right, metal cap. Check thats topped up. When you says jumping, is the needle actually jumping quickly or is it moving between the two in a steady motion??

Check the water in the rad mate. Looking at the car it's at the front on the right, metal cap. Check thats topped up. When you says jumping, is the needle actually jumping quickly or is it moving between the two in a steady motion??

In a steady motion, it takes 2-4 seconds to move between positions, but doesn't pause at any interim value

Yeah would deff check the level in the rad. Sounds like you might have an airlock in the rad so water can something get to the head and sometime the air trapped is blocking it. The most efficient way to check it is topped up is to park on a steep hill with front pointing up the hill, leave the engine running and pour water/coolant mixture into the rad cap openning until fully. Take it for another drive and repeat until constantly full. Be careful when opening the rad cap when engine is hot as the cap itself can be boiling hot and if it is full scalding water will flow out. It is worth keeping an eye on the rad water level for a few weeks to make sure you have got rid of all the air blocks.

 

Always top up the rad but make sure you have water in the expansion tank too above the min level.

 

If the problem keeps occuring you need to figure out why. The most common are; a small leak or split in the coolant hoses (particularly around the jubilee clips) or from the water pump where water is leaking out under pressure during running and air sucked back in when cooling, faulty rad cap which leaks water under pressure due to bad spring and then sucks in air when cooling not extra liquid from the expansion tank due to poor seating (replace with a known good one), or the bad one!!! split in the HG causing exhaust gases to be blown into the coolant (look for even a slight oily film on the coolant surface)

 

Hope this helps

I've just been back out to the car, and there's a puddle on the floor approximately beneath the battery. I checked the passenger footwell and couldn't see any evidence of a leak in there so hopefully it's not the heater matrix.

 

And fortunately I can't see any mayonaise in the oil cap or dip stick.

 

 

Would I be OK to top the water level up and limp home on it (16 Miles) or should I really be looing at fixing it before moving it?

there are different types of HG failure. A leak between the oil and water sides will produce the mayo on the oil cap but you can also get a leak between the water and cylinder sides which will mean combustion products "blowing" into the water and therefore not produce any signals in the oil but will still have the same affects of head warping etc. But i dont want to unduly worry you as if you are seeing a puddle it is more likely you have a leak in the system; coolant hoses, waterpump or radiator but cant see what would cause a pudddle under the battery but i suppose it can run off the scuttle panels.

 

you could try topping it up and getting home in one piece and stopping when the temp starts to climb (or even if it doesnt climb to normal temp is as much of a worry) stop turn off and leave to cool down and retop-up. but i wouldnt want to advise you to do that and you overheat your car badly. it would be best to get it towed I guess. I get free breakdown recovery as a additions account holder with barclays. You could just phone up the AA and join and immediately get them out to tow you if you are really worried.

I had the heater matrix hose from the engine to the bulkhead go and this left a puddle around the battery area..... it was pretty easy to see once I got the bonnet open and looked down the back of the engine.

I've just been back out to the car with a colleague and can see the leak. about 20cm below the battery is a hose coming out of the bulkhead it seems to be open to atmosphere and leaking from there. I can't see underneath the car at the moment to check any further

 

Edit: the hose is angled 90deg and is pointing almost directly down

Coming out of the bulkhead??? I think thats for the AC run off but I'm sure someone who knows what it is for sure will be along soon

The picture isn't perfect but shows roughly which pipe it is