Suspension constantly adjusting

When my P38 is stopped idling the front suspension is constantly adjusting and not just sitting level. It rises up (which causes the compressor to come on) then stops and about 5 seconds later it goes back down again. Then another 5 seconds later it will go back up causing the compressor to be switching on and off constantly so it gets pretty hot.

Watching the height sensors on diagnostics it rises up and ends up going past the target height and then drops back down to below the target height. I've tried adjusting the target height to the numbers it settles on to see if that will stop it but it still does it. Bags are new a few thousand miles ago.

What could this be?

Sounds like 1 of the sensors is giving false feedback
With diagnosis deflate all springs to bumpstops then "get hight readings" see if one is different from the rest

Ohh and before you start messing with the height setting its good practice to make a note of the current settings cos its a complete headache to calibrate from scratch
I learnt that one from experience

NRV 3 could be leaking. When the cars speed drops below 1 MPH the front valves open to equalise pressure across the axle. If the compressor is running and NRV 3 is leaking high pressure air overcomes the exhaust valve and bleeds into the front bags via the open valves causing the front to rise. When the compressor stops air is exhausted to reset height. This causes the front end dance.

wammers said:

NRV 3 could be leaking. When the cars speed drops below 1 MPH the front valves open to equalise pressure across the axle. If the compressor is running and NRV 3 is leaking high pressure air overcomes the exhaust valve and bleeds into the front bags via the open valves causing the front to rise. When the compressor stops air is exhausted to reset height. This causes the front end dance.

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So one of those valve block repair kits with the seals could fix this (if it turns out to be the problem)?

jacckk said:

So one of those valve block repair kits with the seals could fix this (if it turns out to be the problem)?

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If that is the problem yes.

Mine had that problem and was solved when i calibrated the suspension.

JotaPê;2932999 said:

Mine had that problem and was solved when i calibrated the suspension.

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Yes if the heights side to side are to far out that can also be a problem.

jacckk said:

When my P38 is parked the front suspension is constantly adjusting and not just sitting level. It rises up (which causes the compressor to come on) then stops and about 5 seconds later it goes back down again. Then another 5 seconds later it will go back up causing the compressor to be switching on and off constantly so it gets pretty hot.

Watching the height sensors on diagnostics it rises up and ends up going past the target height and then drops back down to below the target height. I've tried adjusting the target height to the numbers it settles on to see if that will stop it but it still does it. Bags are new a few thousand miles ago.

What could this be?

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Nothing should be happening when it's parked other than sinking slowly if there is a leak and levelling every 6 hours.

Datatek said:

Nothing should be happening when it's parked other than sinking slowly if there is a leak and levelling every 6 hours.

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Correct, unless it's a getaway car and parked up with the engine running.

wammers said:

Correct, unless it's a getaway car and parked up with the engine running.

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P38 getaway car, now you are taking the proverbial

Datatek said:

Nothing should be happening when it's parked other than sinking slowly if there is a leak and levelling every 6 hours.

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My bad, I meant to say idling whilst stopped.

tomcat59alan said:

P38 getaway car, now you are taking the proverbial

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Not bad if the coppers are on foot or a push bike.

Datatek said:

Nothing should be happening when it's parked other than sinking slowly if there is a leak and levelling every 6 hours.

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Mine is dumping air the minute I turn off ignition, like it's leveling out but doesn't need too. Gonna change diaphragm Sunday. Will check for more leaks when done.

gazzab79 said:

Mine is dumping air the minute I turn off ignition, like it's leveling out but doesn't need too. Gonna change diaphragm Sunday. Will check for more leaks when done.

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That is because the compressor is running when you switch off. It's not levelling just evacuating the high pressure air when power is removed from diaphragm solenoid. Then valves will click to self level for 20 seconds as ignition is turned off or get out of car and shut the door. Diaphragm has nothing to do with levelling.

Ah ok I get you. Well it's getting done. I def have a leak somewhere, just hope there is a half decent day at weekend.

wammers said:

Not bad if the coppers are on foot or a push bike.

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Wheelchair ?

Could it be the driver pack ?

i dunno! i hate eas. Ill report sunday night

tomcat59alan said:

Could it be the driver pack ?

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Unlikely.