Hi all,

Strange one to explain here.
2011 SD4 has what I can only describe as a hard idle sound.
Does it warm or cold
When in Drive or not. Sometimes sounds quite hard when at the lights so move it into neutral and it does calm down a little.
I did change the autobox fluid but no change.
Any ideas?
Thanks
Ian.

Hard idle. Hm. High RPM? Running like a truck? Not sure what you mean, sorry.

Mine is getting a bit noisy, I know, although recently serviced. Famous last words but I'm going to do the cambelt soon I hope. Getting on and no positive indication it has ever been done.

Having said that I know it'll blow tomorrow. MY11 SD4 SE Auto

Mine made a hard idle sound when the thin blue cable attached to alternator wore through. Cable monitors the voltage coming from the alternator from what I understand, wrong signals could be making the engine work harder making the idle heavier I guess is the only way of explaining.

Only way of checking the cable is by taking the filter out to see the top of the alternator unless you have one those endoscope cameras Corrado VR6 Mystic Blue - Gone
Freelander 2 Orkney Grey

Does the sound change of you put the heated front screen on? Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

May be worth a look at the power assistance reservoir. I just changed mine this morning after getting a groaning noise on low speed manoeuvring. I read on this forum that this was something to look at and found a fluid bubbling effect when I took the cap off with engine running. Suggestion was a blocked filter starving the pas pump. Once reservoir replaced the noise was gone, and the almost stall or stumble on going to idle that I was also feeling has now vanished too, whole drive is now quieter. Perhaps the blocked filter places extra load on pas pump, and therefore loads the idle.

I guess it could be anything that is moving in time with the engine:
Off the top of my head ...
Air con
Alternator
Belt pulleys
Power steering pump
Brake vacuum pump
Fuel pump Jules

Last edited by jules on 24th Mar 2023 1:51 am. Edited 1 time in total

Just changed my freewheeling alternator pulley. Made a huge difference at tick over. Try removing the aux belt and running the engine to see if the noise goes away. If so then start eliminating suspects from there. Good luck

Nodge68 wrote:

Does the sound change of you put the heated front screen on?

Grimdog wrote:

Just changed my freewheeling alternator pulley. Made a huge difference at tick over. Try removing the aux belt and running the engine to see if the noise goes away. If so then start eliminating suspects from there. Good luck