Advice & Tips -
We touched on noises in general last time, oddly enough when an owner brought their vehicle in with what appeared to be a very noisy alternator belt and it got louder on full steering lock, the noise went when sprayed with a light spray lubricant.
It was decided that to cure the noise the owner was told that the serpentine belt required replacement and the car was booked in.
When the car was dropped off for repair, it was found that the noise was now worse and even doing it in the straight ahead position also there was a very bad vibration coming through the steering wheel and column as the steering was moved from left to right, which wasn’t there before.
The noise/ vibration seemed to be linked and further diagnosis was required.
Belt adjustment is carried out by an automatic belt tensioner that maintains the correct tension without having to manually adjust the belt.
In a lot of cases when the engine is running you can see visually that the tensioning pulley tends to move about, in this case the movement appeared to be quite excessive, first thoughts might normally indicate that the replacement of the tensioner assembly would be required as well as the belt.
This particular vehicle had a diesel engine and in most cases diesel engine alternators have a clutch pulley which is there to help absorb the pulses of the engine when it’s running.
When the pulley was looked at it was found to be seized, by replacing the alternator and belt the problem was solved.