C5x7 suspension anti sink query.

[aerodynamica]

Hi all, question for anyone with experience of c5x7 and C6.

I find that overnight the front ride height has lowered enough that unlocking the doors calls for the pump to raise it. Turning on the ignition raises it further. I recall 4 years ago with my c5 that it always raised a bit turning the ignition on but can't recall if it always did this initial raise up after unlocking. Does anyone else's c5x7 or C6 do something like this?

Trying to catch any issues before they get worse.

[Kees]

I think it's possible, that there's some play on the connection rod between the height sensors and the clamp and maybe some difficult movements, because of rust.
But it's also, normal, because, when you unlock the door, you not in the car, then when you make contact you sit in the chair wat wil lower the suspension and the pomp reaction is to correct this. So I think it's normal.

[wurlycorner]

Probably raises more after turning on ignition, because it then has the weight of the person/people in the car so it's just reacting to that?

I don't use my X7 daily, so I can't say if it will drop/need to raise on unlock after that short a period of time - but if I leave it for a week or so and then use it, it does indeed operate the pump when I unlock.
My mk1 C5 Hdi LX (with over 222k on the clock, and all original hydraulic suspension - minus the overhauled pump - and with the boot permanently loaded full of tools) will happily sit for a week and not operate the pump on unlock/start, while my other mk1 C5 V6 (I forget the mileage on that because it's off the road, but starts with a 1...) will need to operate the pump on unlock after a day or so. It's the back that sinks on that more quickly than the front, though.

Not sure if that helps or not - just seems to show there's no correlation pattern

[Kees]

An older pomp don't keep the pressure steady, when the engine is switched off, in the pomp itself sits a little accumulator this one loose some pressure over time.

[aerodynamica]

Hi thanks all. I think I was unclear: I was only asking if it was usual for it to raise when unlocking and before sitting inside. Mine always raises when unlocked

I think Iain has kind of confirmed it can happen.

[PaulC5]

I also used to find our C5 in hot weather would be a bit high before unlocking so would lower itself.

[aerodynamica]

I also used to find our C5 in hot weather would be a bit high before unlocking so would lower itself.

I've seen mine do this too

[the-termin8r]

If I go to my car in the morning and the pump doesn't sound when I unlock it I start to panic a bit. My pump sounds for a bit and then stops, admittedly I don't pay attention to how much the car raises, but it shouldn't be much. Likewise, when I turn the ignition on, the pump goes again, even if I'm not necessarily sitting in it. I've made it a habit of turning the engine over once the pump stops. It's more for the glow plugs than anything even though they're much faster than that. When I get somewhere and turn the engine off, the front of the car noticeably dips most of the time. My 3L doesn't always do the nose dip, if I'm on a slight gradient it will keep it up. Then when I unlock the car after coming back to it the nose will dip. Not sure why the 3L does that, hasn't caused me issues for now though.

[aerodynamica]

Hi Rob. That a sounds the same as me.

I did see that when I had the lexia connected in the ride heights menu, the number of steps for the front height with ignition on changes when the ignition went off. That says to me that there is a set height for the car when it's running and another set height (lower) for when the engine goes off. Perhaps for some kind of parking stance....

But the thing about the pump raising it unlocking in the morning seems that the height was already lower than the lower set height for parking and that surely means it sinks further overnight.

My glow plug lamp barely ever comes on...

[the-termin8r]

I haven't dug around in Diagbox on either of mine to see any settings. Regarding the overnight sinking, I'm not sure. I don't think it's an issue unless you're feeling some sort of change in the car's driving behaviour. My glow plug light always comes on but for only about a second.

[PaulC5]

If the car was kept in a heated garage overnight the lds might not cool down and the car not sink a bit. I vaguely remember reading the C5(X7) lowering a bit as normal when the engine is turned off, maybe there is something in the handbook if anyone wants to look.

[the-termin8r]

I don't have a garage so both cars have always been parked outside in my case. I've read the handbook cover to cover but I don't think it mentioned anything.

[albertosilvestro]

You described the normal operation of the hydractive 3 plus suspensions, I don't know about the other generations, my C5 X7 has always lowered when it is turned off and raised when it is unlocked.