2000 XKR and got this warning for the first time yesterday. I was confident I was not losing coolant and so off to the web for a look. Turns out this is a well documented problem with varying levels of complexity (and cost) to achieve a fix. All problems and solutions seem to be in the coolant overflow tank and its contained sensor assembly

Logical approach. Coolant level to base of filler neck? Check. No air locks (squeezing left radiator hose)? Check. Float moving freely on the sensor rod as evidenced by use of a plastic spoon and torch? Check. Put screw driver in tank and gingerly wave it around for a magnetic rod to spring on to it from the depths of the tank. Oh dear. Retrieve screwdriver with offending rod. I say 'oh dear' because perceived wisdom would appear to be that you are now up for a new overflow tank with sensor assembly as it is impossible to put the magnetic rod back in the float whilst just working through the filler cap.

Well it isn't. Fiddly, yes, but not impossible. You do need some rather arcane tools though. Empty overflow tank with 60ml syringe so as not to have to drain everything (large syringe not that hard to find). It is then easy to rotate the float to find the hole where the magnetic rod belongs and bring this to be opposite the filler cap through which you are forced to work. I then employed a 8" surgical needle holder to enable accurate apposition of the rod into the hole whilst peering through the filler cap with a LED torch. Now the fiddly bit. The rod is a snug push fit into the float but it has to be EXACTLY in line with the hole in order to be pushed home. This just requires patience - and the correct tools - to get the alignment just right before it will push home. Refill the overflow tank, snug down the cap and turn on the engine and no more red warning light and 'Low Coolant Level'. Bliss - and hundreds of dollars saved.

Thanks to this forum for even me putting me in the correct ball park as to where to start. So glad I didn't have to progress to the wiring bits.

 

Good write-up, I have had the warning for some time now and will give this a try. Did you by any chance take pictures, or know of a thread that shows the arrangement of the float/rod?

Many thanks!

 

Pride before a fall.

I must admit while still basking in the glow of satisfaction of a job well done the thought crossed my mind 'If this silly magnet has fallen out once, what is stopping it doing it again?'

Well, nothing it would appear. Everything was fine for about 70km and then the red light and 'Engine Coolant Low' reappeared. This morning went through the same process and surprise, surprise the magnet was not in the float. Nor was it anywhere else. It is certainly not in the overflow tank and I can only assume it has fallen down the big pipe at the bottom of the tank from where presumably the overflow gets into its tank. An optimistic fish with a M5 nut on a light string down the pipe was no more than that - optimistic.

Now what? I reckon I'm stuffed and will have to buy a new tank, sensor and, if modern spares departments are on form, the entire front half of the car.

I trust this damned little rod will do no harm wherever it is - I can't see myself ever finding it. Unless there some good suggestions from those much more experienced than myself.

 

A pragmatic approach is probably the way to go,otherwise you may drive yourself nuts.
Chances are the magnet will land in a corner somwhere and stay there, if by chance it finds a critical place to stop and cause a problem, the problem will alert you and the mystery will be solved.

 

I had this this morning. But the red light and warning goes off and on. Bit weird given my rceent cooling issues and everything was overhauled. I'm hoping there's no leak anywhere. Like I said the red light and message are intermiitent and there is no sign of overheating at all.

Anyone else had anythng like this? I'm waiting for car to cool now so that I can check level etc.

 

prob going to need to do a system pressure test when it is off and cold. That is how I found a leak that I could not find.

 

when that light is coming and going, when it is cold do you check the resisor tank? How full is it?

 

Yeah. The expansion tank was a little low. I topped it up - did a 100 mile run, no more red light or message. Just gotta watch on the next run now. If it goes low again, won't be rocket science to guess there's a leak somewhere. Lets see!

 

if you just did work to the system and fluid was let out ( a lot) it may take 2 or 3 times that you will have to run it then cool down and top off before it settles in provided there are no more leaks. Fluid should come up right to the bottom of the opening to the tank.

 

Yeah the system was completely flushed cause a new radiator, water pump and thermostat was fitted. Its what I thought. I actually dont think there's a leak at all. Like you said - settling in.

 

FWIW, my car would show "Low Coolant" light occasionally with NO LEAK. I could free the tank float with a wire hook and all would be great for 2-3 weeks, then it reappeared. The float would bind on the probe and not show correct level. Purchased a new replacement tank from E-Bay vendor for $100 incl S&H and all is well.