Mini one 1.4 petrol - Knocking noise timing cover area 2010 mini 1.4 pet - David Welsh

Hi I'm new and hoping someone can help with some advice. After a long journey to Manchester and back my daughter's mini has developed a rhythmic knock from the rear of the timing cover area. It disappears if the revs are raised over about 1500 rpm. I know about the timing chain issues but with hers there's no chainsaw type grrrr noise just the knock. I've also heard about vacuum pump issue so I took off the small bore pipe to the pump but noise is still there and tbh I'm not sure how the pump could cause that noise as it's at the other side of the engine. Anyone heard of a time when the noise was something other than the chain or pump?
If it is the chain I will do it myself and see there are kits for £70 on eBay and also locking tools for about £40, anyone had any experience of using eBay stuff to fix this. Anyway thanks for reading.

Mini one 1.4 petrol - Knocking noise timing cover area 2010 mini 1.4 pet - elekie&a/c doctor

The water pump on these is driven by a belt and friction tensioner.I would take a good look here as it is possible there is a piece missing out the belt and damaged the tensioner. Hope it's not the chain,it is a massive job on these as you need to drop the sump and it is essential to use the correct set up timing tools (which also do the Peugeot with the same engine).Tools from the 'bay are probably ok,not sure about the chain kit.

Mini one 1.4 petrol - Knocking noise timing cover area 2010 mini 1.4 pet - David Welsh

Hi thanks for the reply I did notice the friction drive setup for the water pump and I'm hoping its maybe from that. Do you really need to drop the sump? The videos on YT for chain replacing makes it look fairly straightforward (in comparison to some that it) apart from the need to lock the cam/crank as there's no keyways on these theyr all locked by the torque of the bolts. Just making sure I haven't looked at the wrong engine. Thanks again.

Mini one 1.4 petrol - Knocking noise timing cover area 2010 mini 1.4 pet - elekie&a/c doctor

I think you need to drop the sump to replace the second chain that drives the oil pump.If you do replace the chain,make sure you use a new crankshaft bolt.

Mini one 1.4 petrol - Knocking noise timing cover area 2010 mini 1.4 pet - gordonbennet

Groan, who started this idiotic trend for removing woodruff keys, first engine i recall having this set up was the 2.4 Diesel in VW LT vans (same engine as fitted to Volvo 7/9 series).

Similarly, why remove the simple timing marks that all engine sprockets/castings had at one time, some makes even had (still have) corresponding marks on timing belts fr double checking the right tooth is engaged.

The cynic in me thinks its purely to prevent mechanically minded owners completing all maintenance themselves.

Mini one 1.4 petrol - Knocking noise timing cover area 2010 mini 1.4 pet - David Welsh

Update, was the serpentine belt was breaking up and causing the water pump friction drive to bang as the worn part passed over it. Cost of a new belt fixed it...Result