funny noise

I've got a D2 '99 TD5 and today it came up with a new problem. After turning the ignition off and removing the key there was a deep noise, like a motor trying to turn but being stuck, or a pump - sorry, hard to explain a noise in text.

It's made the noise before but for only about 5 seconds after the key's removed, I thought it sounded like some locking bolts moving into place to deadlock the engine or something.

Today though the noise carried on. Left the landy for about 20 minutes, came back and the noise was still going. It changed in pitch when the ignition lights came on - slightly higher pitch. Then when the engine fired up it sounded like something was catching for the first couple of seconds, like a clattering sound, then all was normal.

Drove home, took the key out, same again. I got out and the noise didn't seem to sound like it was coming from any part of the disco in particular.

Disconnected the battery and it stopped, reconnected the battery and it started again. Much swearing, but to no avail.

Because it sounded a bit like a pump I decided to have a go at raising the air suspension, so I put it into off road mode and it raised up no problem, then I dropped it to normal height and switched the ignition off. This time there was no noise.

Fired up normally and switched off normally with no noise.

I'm just wondering if this is coincidence and it will come back again or if this has cured it.

Anyone have any ideas what it could have been?

Hi there,

Sounds like the compressor running all the time. Yes they do run for a few seconds when switched off often to level things up as normal. If after you have raised the back and then lowered it it goes away then you have got a small hole near the fold in the bag. Small sharp stones get in the fold and rub a pin-prick in them. When you raise it and leave it I assume that it will run and run? When you let the back down again it seals the hole under pressure and the compressor stops. Change the bag or bags as soon as possible or you'll wreck your compressor.

Hi Borntobemild.

When I raised it to off road height it seemed to get to the right height ok. The compressor ran for a minute or two and then stopped. Is there a test I can do to see if the bags are knackered?

It's the ABS modulator...the valves are resitting within it...sometimes for longer other times faster...and also the slabs ECU is powered for up to 2.5 hours after ignition is off and the system tends to keep level...it's a D2 thing, dont bother with it... as the components are older they make more noticeable noises ...if it stops within 2 hours disregard it, if it will last longer then it worths further investigation

Cheers - that puts my mind at rest

Or.....

The contacts in the SLS relay on mine welded themselves together so the compressor was on all the time - it made quite a racket as of course both valves were closed. Might be worth a look - swap with the headlight washer relay if you have it as that is usually in good condition.

The tried and tested way of finding holes in the bags are to extend them and spray with a solution of washing up liquid and looking out for bubbles.