Hi all
I have an audible chirp from my drive belts when the engine is cold, I found this on another site, has anyone had this done under warranty? or changed the idler pulley themselves?

No: LTB00067
Issue: 2
Date: 23 Jul 2007

Audible 'Chirp' on Cold Start
AFFECTED VEHICLE RANGE:
LR3 (LA) VIN: 5A300360 Onwards
Range Rover Sport (LS) VIN: 6A900290 Onwards
Range Rover (LM) VIN: 6A194480-7A257088
CONDITION SUMMARY:
BELT MOVEMENT GENERATES NOISE
Situation: Audible 'chirp' on cold start in a rhythmic pattern is heard coming from the front end
accessory drive (FEAD) belt because the drive belt is "wandering" on the idler pulley.
Action: Should a customer express concern, install a new modified idler pulley and FEAD belt. Follow
the Repair Procedure in this bulletin.
REPLACE "FEAD" BELT AND MODIFY FAN PULLEY BRACKET
NOTE: Global Technical Reference (GTR) lookup sequence is as follows:
GTR Home > NAS > Vehicle LA, LS or LM> Service Information/ 2007 > Workshop Manuals >
Bookmark "Powertrain/Engine/303-05" LINK "Accessory Drive Belt (86.10.03)"

1. Refer to GTR Workshop Manual, Section 303-05
(86-10.03) and remove the idler pulley and FEAD belt.
2. Undo the five bolts and remove the fan pulley bracket.
3. Place the fan pulley bracket in a vice.
4. Modify the bracket using a suitable file or grinding tool
as illustrated. (Figure 1)
5. Install the fan pulley bracket and tighten bolts to
22-28Nm (16-20.5 lbf ft).
CAUTION: The minimum recommended clearance
must be obtained.
6. When the new idler pulley is installed, verify a minimum
of 1mm (0.040 inch) clearance to the pulley mounting
bracket.
7. Refer to GTR Workshop Manual, Section 303-05
(86-10.03) and install the new idler pulley and FEAD SC 4.2, 2012 face lifted, 25K miles, 1 previous owner
Triumph TR6 1973
Triumph Bonneville 1970
Previous:
2002 TD6
Merc SL500
Escort RS Cosworth
RR 3.9 Vogue
4.2 E type Jag replica (challenger)
Escort RS2000 (many)
Escort RS 1600 Turbo

Done a few of these in my time at the main dealer.

Invloves removing the bracket, and filing some of it away, and fitting a new belt

Though on the FFRR, from memory, the Air Con needs drained and regassed, as the pipes run over the fan cowling...

Mine did it in the winter when I first got it 3 years ago, sprayed the FEAD belt with silicone spray when the engine was going and it instantly stopped.

Came back last year after a long motorway drive through salt spray, did the same and it dissapeared instantly

Had my local garage inspect the belt closley last year when the air con was regassed and he said it looked like new.