Strange Noise On Shut Down

[ak]

With my TD5 after I turn it off I have a buzzing short and sharp sound, like two sort bursts of noise. Does not do it every time I turn the motor off only sometimes which is the strange part.

It's not the central oil filter whirring down it sounds competely different to this.

Any ideas what to look for?

[George130]

Could it be electrical?
Doesn't sound good what ever it is.

[ak]

Could it be electrical?
Doesn't sound good what ever it is.

That's what I am thinking has to be electrical due to the motor being shut off, but no idea where to even start looking.

[George130]

Try starting with the wires around the steering column. Might be a loose connection that gets upset when you turn the key. After that good luck and you might need 2 people. One to shut down while the other moves around the vehicle trying to find where it is coming from.

[ak]

Only other thing I forgot to mention that's different is the noise has started since I got some driving lights fitted to the front. I not sure if it could be related.

[George130]

That could do it. Check the switch connections and where you tapped into the power. I would say it is the cause.

[Blknight.aus]

manually turn the sound system off before shutting down the engine and see what happens... it might be transient voltages buzzing the amps on the 12v hot supply to the head unit.

but thats a WAG.

[ak]

Thanks for the replies. Trouble is I have been out in the garage turned the car on and off four times and you would not believe it can't find a trace of the sound. As said it only does it every so often and it will be most likely in the morning when I am pulling up at work and don't have time to fiddle about. Murphys Law.

[DEFENDERZOOK]

does it make the noise if you only turn the ignition on and off......without actually starting the engine......?

[DEFENDERZOOK]

does it do it when the lights are on.......?

[ak]

does it make the noise if you only turn the ignition on and off......without actually starting the engine......?

No, only after the engine has been running. Has done it adout 4 times in the last 6 days. Seems to be random. Which is why it's really got me stuffed.

[Slunnie]

Did you have air lockers fitted? :D

[ak]

does it do it when the lights are on.......?

No lights have been off every time ( during the day ) and it has not made the noise at night yet after the lights have been on.

[ak]

Did you have air lockers fitted? :D

No Slunnie, she pretty much stock except for the spotties fitted 2 weeks ago.

[davros]

The valves on the air suspension compressor make a whirrrr.... click..... whirrrr... click! Maybe 3-4 times after shutdown, sometimes they hiss a bit. Weird and I don't want to know in if its expensive fellas! Suspension is fine. Its like some presure valve letting off a little till things are set correctly?

Dave

Thought I might it doesn't always happen. It's loud enough to easily be heard.

[Graeme]

Any chance that the electric fan is touching the driving light wires?

[azz419]

Just a thought, it's not the ABS accumulator, obviously only if it's fitted. You can hear them on some vehicles, I can't remember if you can on Landy's or not.

Azz

[davros]

What was it making the noise? Can't sleep in anticipation of finding out about something else thats going to happen to mine!

PS when u say td5 did u mean disco or defender?

[ak]

What was it making the noise? Can't sleep in anticipation of finding out about something else thats going to happen to mine!

PS when u say td5 did u mean disco or defender?

It's a Disco TD5 and there has not been a trace of the noise for the last 4 days. Fingers crossed it does not come back. I surpose it's a matter of if it now does not appear to be broken don't try and fix it.

[ak]

Well the noise has come back in stops and starts. So I phoned my Landie speaclist to describe. Ward at Coopers said it's most likely the air compressor on its last legs. What happens is the car gives the air compressor a 30 second window after shut down to pump more air into the rear springs if needed. All D2's with SLS do this, which is the same or reverse of letting air out. The car wants to get level. I did not know you learn something everyday. So when the compressor goes I will seriously considered coils as the price of a new compressor won't be cheap.

[ak]

Should clarifly, I knew about a D2 with rear SLS wanting to get level, but I did not know about the 30 second window the car gives the compressor after shut down. This explains the on and off mystery noise on shut down.