Got an issue with the compressor playing away to itself most of the time still.

Every time I start the car, the ride height flashes for a couple of secs and the orange "going up" symbol comes on the dash as though to say it's going up but the car actually never moves anywhere.

Compressor kicks in and out all the time and at traffic lights with foot on the break, sometimes you can see a little dance up and down of the front end if you watch the bonnet.

Yesterday I parked up and as I got out, I noticed that the back was higher than the front by a good 2 inches or so. looking at the distance between the wheel and the arch.

I'm wondering if it's a faulty height sensor at the front?????? How do you check these?

I don't lose any air when parked up and I'm fairly confident that's it's air tight. Block and compressor were rebuilt. about 6 weeks back.

I recall that when Morat put his Nanocom on it, the EAS reported an "unknown fault"

Any ideas?

Thanks

Get yourself (or make) the cable and use the RSWUnlock software but it does sound like you may have an iffy height sensor.

Got all that gear from the last time we did the fault dance.

No faults listed.

Any chance Relay 20 could be to blame?

Relay 20 turns the pump on and off so it could explain the pump cutting in and out if it has gone intermittent, try swapping it with one of the others but I doubt it is that in all honesty. What heights do you have set? Is one corner significantly different to the others? Rumour has it that if the settings are more than a few points out it can cause a problem. If you check the height sensor readings at all heights do they look right or is one not moving smoothly? The other thing is the driver pack or connections between the driver pack and valve block might be playing up.

I noticed that the front left was below the rest.

I put it down to unlevel ground. I'll get it level later and read them again.

When I'm at traffic lights with my foot on the brake, the compressor can be heard running. 9 times out of 10, as soon as I take my foot of the brake it stops. Too often to be a coincidence I would think.

Could a faulty pressure switch cause the same symptoms? I'd guess that if it wasn't closing or reporting pressure, then the compressor would be told to run? I saw a video about checking pins for the pressure switch to see if it's open or closed.

You sure it's the compressor you can hear and not the ABS pump? I can't hear my EAS compressor even without the engine running unless I take the lid off the box. ABS pump running when your foot is on the brake suggests a dying accumulator.

Nah definitely compressor. When I go to switch engine off, sometimes it's running and switches off a split second after.

Don't they all dance at the traffic lights?

no mate. nothing like that. just the bonnet sometimes bounces a bit like it's struggling to settle on a height. I'm gonna get out and find a flat spot in a bit and get the sensor heights as Gilbert said.

If you've got your foot on the brake they shouldn't dance no matter where you are. If you've got one front sensor saying one thing and another saying something different it will try to raise to match one but then find the other says it's too high so it will adjust and so on. But with the brakes on, it should just sit there and do nothing.

Mine seems to overshoot a bit if you release the brake after a decent stop. It takes a couple of attempts to find an acceptable setting. It doesn't bother me, just makes me chuckle as It does a little jig.

I went out tonight and found a flat car park.

Using EAS unlock, I went to calibrate and then "Read All". I assume these numbers are what my suspension heights are supposed to be calibrated to?

I then set the suspension to each ride height in turn and then clicked on "Get Height" to get my current height.

The readings are:

Does anything there look wrong?

One thing I did notice whilst tinkering, is that when I clicked "up" on the front left corner, the front right corner went up and vice versa. Have I plumbed front left and right airlines in the wrong way around when I rebuilt the block???

Heights look right but it definitely sounds like you got your lines crossed. The lines should have coloured sleeves at each end on them. Check to see if yours do. As you look at the valve block from the other side of the car there's the 4 outlets for each spring and the ones toward the front of the car are for the front springs. It should be front right (green sleeve) at the top and front left (no sleeve so black) at the bottom. If they are no longer wrapped in their loom, it's easy to get those two mixed up.

Sounds most logical that ive got the lines the wrong way round.

If its telling itself that the left is low and tries to blow it up but then the right goes up instead, its going to argue with itself all the live long day isnt it.

swapped the left and right lines around. dunno how I managed to get them the wrong way around though. They weren't twisted.

I still reckon the compressor is coming on more than it should. Traffic lights, foot on brake, compressor on (not every time though)

As soon as I take my foot off, compressor stops.

Could a knackered cruise control line be anything to do with it? Do they share the same circuit? I noticed today whilst I was steam cleaning that the line going from the diaphragm along the bulkhead had quite a few nasty cracks in it at the diaphragm end.

Won't be the cruise line- that's vacuum, driven by its own pump and not connected in any way to the EAS.
I rebuilt the EAS compressor when I first got the blue car a few years ago and then spent months listening to how often it ran. Same as you, traffic lights/ junctions with foot on brake quite a lot. Got bored with listening out for it after a while and the EAS is still working fine so think it's just normal (ish) behaviour

Put the washers on the EAS pump the right way up and the problem will be solved, you'll never hear it running without sticking your ear to it. On each mounting point it should have two dished washers. The bottom ones should be concave side down and the top ones should be concave side up.

Lol. Its driving.me mad cause i know its there.

I only moan about this stuff cause on the first p38 i had, you couldnt hear a thing. So im using that as a benchmark.

The washers are on the right way. I followed your advice on that a month or so back. Mountings are new too.

Gilbertd wrote:

Put the washers on the EAS pump the right way up and the problem will be solved, you'll never hear it running without sticking your ear to it. On each mounting point it should have two dished washers. The bottom ones should be concave side down and the top ones should be concave side up.

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I put mine on the wrong way up on the blue one deliberately, just so I could hear it and thus, worry about it. Seems a long time ago now that I had that "my first P38" paranoia :)
I still have the paranoia- just about different things on the cars, well the black one anyway. Blue one just gets used and maintained on an "as required" basis.
Current favourite- the inexplicable difference between the two engine temp outputs on the black one.