Anyone know the part No, for the serpentine auxiliary belt on the sigma engine.2011 4/4 and indeed the tensioner unit and pulley.
I can't quite read the belt No: 6PK1203 or 6PK1208. As for the tensioner well much googling with no luck, except an eye watering priced Caterham one that looks similar.
why am I looking, well a rather noisy front of engine on cold start. Quietens once warm, but still a rather noise pulley.
thanks in advance

When I needed a belt for my Feb-14 4/4 with the 1.6 Sigma engine, BHM supplied a Gates 6PK1203 belt which fitted perfectly.

Do you get a squeal on start up that goes away very quickly? If so, it may be that all you need is the belt.


If you need the tensioner unit, have you tried Burton Power ?

Also, Ford have an eBay shop for parts.

As I have said on another recent thread, the 6 is the number of ribs and the 1203 is the length. It is important to get that correct as the tensioner is simply spring loaded so if you get one too long, it will end up floppy..
You don’t say what sort of noise you are experiencing. If it’s a squeal, then it could be the belt slipping under load, typical of when the alternator is working hard to recharge the battery after starting. i.e battery is in poor state of charge.
If you have a squeal, a small squirt of WD40 on the belt whilst running may immediately quieten it. No cure, but rules out the pulley and tensioner.

OEM part for 4/4 Sigma V belt is a Gates 6PK 1203. Fitted in 5 minutes from memory a 15 mm socket on the tensioner

Great thanks for the belt no. The noise on start when cold is like a dry bearing with no squeal, but also has a clack clack noise superimposed. The clack clack almost disappears after a while but leaves the dry grating noise which also almost disappears after a run. Getting head quite close it does sound like the tensioner pulley. However it is definitely from the front of the engine. Other culprits may be the cam belt tensioner. (Cam belt changed 2 years ago) or the auxiliary idler wheel.
If I can get at least a new belt & pulley, I will have a go at running the engine without the belt for a short while from cold. Oh I am fairly sure it is not the variable cam actuators.