Thanks madf, I have been searching but can only find mostly diesel cambelt changes. Still looking tho.........cheers.

Hi Chris M

Haynes is a must but I'm having difficulty finding the correct one. The car is a Mk7 57 plate fiesta but the Haynes only list the Mk7 from a 08 plate onwards. Would this be the one to get?

Locking tools are a must I'm guessing. eBay is probably my best bet.

In my experience changing a cam belt is not that difficult but accessing it can be. On one engine we had to support the engine and remove the front engine mount. On another the timing marks would only have been visible with the engine on a bench (or remove inner and outer wings). Solved that by putting lots of marks on pulleys etc before satarting work.

On a Ford with a stretchy belt there is no option but to renewthe auxilliary belt, the old one normally has to be cut off.

Not 100% certain about the Sigma engine but on the Zetec the cam locking tool must not be used to hold the cams in position whilst tightening up the cam pulleys, You will damage oreven possibly break the cams. Same with the TDC finding tool, use that to hold the crank in position whilst tighteneing the bolt and its goodbye crank.

Holding the crank is best done by using the ring gear and a suitable tool and the cam pulleys need a suiltable tool and a 2nd person for tightening. Haynes details the tools plus showhow to make DIY alternatives. They work a treat.

the timing marks are already there, you line them before removing the old belt to check, loosen the tensioner, slip the old belt off, swap out the tensioner and idler for new ones, put the belt on ensuring the marks are still alingned and pull the grenade pin on the tensioner, job done,

If you simply rotated the engine to align the timing marks on a Ford Zetec and removed the belt without locking the cams they would rotate out of position due to the force on the lobes form the valve springs, the cams would settle to the position of least resistance. It is then a difficult job to get them back into position, I know, you have to when you build an engine from scratch or even change a head gasket.

no touching the auxilliary belt no crank or cam pulleys to bother with.

You should be able to get by without touching the cam pulleys but you have to remove the crank pulley before you can remove the bottom part of the belt cover. On newer Ford engines there is no keyway on the crank thus replacing it in its original position is virtually impossible even with loads of paint marks. Not sure if this applies to the Sigma, the Haynes is in the workshop but the Mazda Duratec is inflicted with this complication (but that is a chain cam of course). None of the recent Fords have keyways or dowels on the cams which is a right pain when rebuilding.

The camshafts on the Sigma engine have flats so you can use an open ended spanner to hold.

Fiat's Fire engine used to be one of the simplest to replace the timing belt on, but now they have gone the Ford route so locking tools are required. I'd be interested to know why. Could it be it makes production cheaper or is it that it makes timing more accurate and hence emissions are better controlled leading to lower VED?