996 water level light at 130mph+

[markxw]

While vmaxing at bruntinghtorpe yesterday, the water gauge light on my 996 C4 kept coming on at high speeds, and was flashing (not one of the yellow or red warning lights, but the red light at the top end of the water temp gauge). Looking in the manual, flashing means low level of coolant not high temp. Let the car cool down and had a look, and level was absolutely spot on. It happened 3 times and every time when i stopped and restarted the engine the warning was gone. Temperature was absolutely perfect right in the middle of the gauge all day and everything else was absolutely tickety boo.

So - what does anyone think? Just related to hard acceleration and braking confusing the sensor? Anyone else see this happen in the past?

[gfreeman]

This is a very common problem although it takes a minute amount of fluid to go from covering the sensor to 'light on'. If you overfill a bit it will spit it out. It is probably due to the extra few degrees of heat expanding the system a bit.

Just keep an eye on the header tank which on some examples, was prone to splitting. As you are not losing coolant it doesn't sound like a split tank, so just switch off/on and carry on. Check your coolant regularly and stroke her now and then.

[S1XXR]

might be a faulty or loose sensor.

I had the same problem but with the oil pressure gauge on my old 996 C2.

Ask your dealer to check it.

[BliarOut]

Mine does it too. Seems to spit just enough coolant to get fractionally below the low level and then sorts itself out. Annoying, as the light only comes on when you're 'playing'. One suggestion is a small airlock that expands when you go for it. Plausible, as apparently they are a bugger to bleed.

[markxw]

Great stuff guys, thanks!