D4 Suspension Compressor over temperature warning

[David Hannett]

Hi all Recently had the D4 at Stockton beach for a 'Sand' training day and experienced issues with the suspension compressor over-temperature warning not allowing us to select off-road height.
We had done about 7 runs up the first dune of the day (the easiest) and had been doing our usual thing of lowering to access height to hop in and out after each run - and raising again at the start of the next run.
The compressor over-temperature warning came on and any further raising became very slow (almost imperceptible) and situation remained even after a 30+ min tea break to give the compressor a chance to cool down - we ended up abandoning the day.
I was surprised that the compressor was apparently so sensitive to that amount of use but more so by what seemed to be an ordinate time to cool down sufficiently which it didn't do even after an hour or so of stooging around. (Mild 26 degree day slight breeze)
Landrover say that this behavior is normal and there was no hard fault recorded.
Is this normal behavior? and should i just avoid exercising the compressor by changing height unnecessarily as the most pragmatic solution?
Landrover cant tell me how much use is 'over-use"
I did expect that it would be more robust temperature-wise that this but maybe my expectations are misplaced? Cheers David

[Graeme]

You need to avoid changing heights unnecessarily as the compressor seems to be only for occasional use. The system pressurises a reservoir to a much higher pressure than required by the air-springs and this overheats the compressor very quickly. It might be acceptable in cold climates.

I think the small high-pressure reservoir is a bad design and I may unplug the electrical connector to the reservoir valve. By doing this, the compressor will not be pumping at high pressures and thus not generating the heat, but will have to pump the air-springs any time a height increase is required.

[Celtoid]

Hi David,

It's not a fault, the system just wasn't designed to make full range movements too often. Whilst there seems to be a lot of variation between vehicles on the speed the system moves to off-road height, there can also be variations on the one car. In other words, some days mine will extend quicker than others.....daily temp and how much it's been used, etc, I imagine.

Cheers,

Kev.

[gghaggis]

Going from off-road to access and back again a few times will heat it up quite quickly. You can remove the lower plastic cowling around the compressor to help cool it down - the sound absorption material in there also works as a great thermal blanket!

Cheers,

Gordon

[stig0000]

just so you no,, the comperssor cuts out at 120deg, so yes it is very hot,

[Graeme]

Is that temp for the brushes temp sensor or the compressor head temp sensor and which one gets hot first?

[David Hannett]

Thanks to everyone for your very helpful advice....