I just got home from a 50 or so mile drive in my new to me 2013 SD4. I noticed after it had been parked for about 5 mins that there was still a whistle (constant pitch noise) coming from behind the grille. It wasn't really loud but certainly loud enough to hear with no traffic around. Anyone know what it is and if it's normal?

Many thanks,

Just noticed the same sound starts up when I unlock the car?

They all do it to a greater or lesser degree.
Its been said on the forum before exactly what it is...escapes me now. However, its "normal".

Oh... just read your second post, whilst I was typing the first... don't know now! Im sure someone more knowledgeable than me will reply.
MM

Its a valve setting on the engine as its an oil burner so it starts better iirc.

T Terran



'The' Car For The Modern Day UK Roads ( ie all the pot holes )

'A Freelander that leaks oil is just marking its territory' - Wise words

Now a member of the FL2 'Silly Bill' Club

Throttle box resetting. p****d off with a Digital Keyboard Warrior

Thanks for the answers and I have no knowledge other than experience of other vehicles to doubt any but something resetting would surely reset and be done with it? Something to help the engine start would make sense on unlocking the doors, but why would it do it at the end of the journey?

This whistle starts the moment I unlock the doors and is still going at least 5 minutes after switch off and doors locked etc. Like I said, it's not overly loud, just noticeable if you happen to be standing at the front of the car.

Any other suggestions?

Mine does it, always has, sounds like a pump running to me.

+ 1 electronic throttle reset. Normal.  _________________
Gone - 2010 Rimini XS

How long does it take the throttle to reset, mine goes on for minutes on end?

The throttle box does reset itself after shutdown but only for seconds in length (unless there are teeth missing and the stepper motor cannot find its home position).
I would say the noise heard for a longer time would be the 'coolant fan' running for a pre determined time from switching off after a long run.

OK, so then considering it's the exact same noise that can be heard when the car is switched off and then much later when unlocked again, I wouldn't think it's going to be the cooling fan either. I'd like to think I'd know what a cooling fan would sound like. This is more of an electronic whistle than a mechanical sound if that makes any sense? I might try to take a recording on the phone later. I'm not worried about it by the way, all my recent vehicles have been heavily laden with electronics and have made all sorts of odd noises... I am just curious to know what this is.

I just got back from driving into town, pulled into my drive and lifted the bonnet. The only sound I heard is the throttle body motor re-setting itself for a length of about 10-15 seconds and then it stopped and all was silent, and as others have said is normal as every ignition cycle it calibrates itself by fully closing and opening the flap, but for it to go on for 5 minutes

The sound of my throttle body reset was a quiet 'whine', not high pitched but slightly down the scale of a small motor running.

5 minutes was an exaggeration. Not deliberate I assure you but I've done a little more checking myself today and clearly I must have unlocked the car or something yesterday to make me think it was 5 minutes. However, the noise is heard for at least 30 seconds I would say after unlocking and 30 seconds at least when switching off, after locking etc.

It doesn't sound like anything is broken, and so unless there's any further suggestions I'll put it down to the throttle body motir as I agree its a quiet whine and down scale.

Thanks for all the suggestions and advice... appreciated as always.

The high pitch sound is the pulse width modulation signal that gets sent to various valves around the engine. It used to be solenoids that open and shut valves, but now they use variable motors to do the job, the amount they open is controlled by pulses sent. The throttle body being a good example.

When you turn off the engine, the ecu opens and closes various vales that are meant to lock down the air supply to the engine, and also let various gases breath out. This is to stop the possibility of overrun by the engine beyond the point of the ignition being turned off. ( cause diesels have the potential to continue running on the engine fumes )