Technical mk1 55 s crank pulley knocking

[MadMan0]

Hi all.
The fault free Punto is back after 18 months with a problem. mk1 55 s 1.1L 8v manual

There is a slight knock from the cam pulley. I have had the timing belt cover and cam cover off to try to find the problem. listening to the engine via a metal rod there is a grinding sound, your not able to hear this without listening via the rod. The cam pulley moves slightly back and forth while the engine is running but I cannot move it while the engine is off.

I think it's the cam pulley bearing. Does anyone have any more exp with this type of problem? Does this sound about right? (thinking it's a bearing issue)

I serviced the car yesterday and the noise has softened slightly but is still present. The car is used for motorway driving + to the gym and back.

 

[fingers99]

Cam pulley bearing is integral with the head.

When was the belt/tensioner last changed?

 

[MadMan0]

24th Jan 2011

 

[fingers99]

OK. Check the camshaft for end float. Then, pull the cam, look for any scoring on the cam bearings (or even the circular bearing surfaces of the cam itself).

 

[MadMan0]

Could you explain a bit please, what is end float? and how would i pull the cam?
I tried to move the cam pulley and couldn't get it to budge any. The cam shaft it's self looks good. no scoring on the cams, a good oil covering also.

 

[fingers99]

Don't go any further without buying the Haynes.

End float is movement along the length of the camshaft. Ideally you'd fit a dial guage and tug on the pulley. More crudely, pull and push on it and feel for movement. Should be barely discernable.

To remove the pulley you need some way of locking up the cam. The haynes gives safe ways of doing this.

You need to remove the pulley (ideally) before you remove the cam. The places you're looking for wear cannot be seen with the cam in place.

 

[MadMan0]

Thanks for that.
End float is what i thought it was
I may need to dig out the manual, not used it for a long time.

I couldn't find any end float when i tried but i didn't use a gauge of any kind, it simply did not budge. So it sounds like the bearings are the way to go then?

 

[fingers99]

Possibly. You might try measuring the valve clearances before you remove the cam, though.