EP6 - 1.6 VTi Knocking Noise From Tensioner

I recently noticed a knocking noise coming from my wife's C3 Picasso, which is fitted with the lovely EP6 1.6 VTi engine (120bhp).

I honestly thought the bottom end was gone, but I got a second opinion from a mechanic friend of mine, who said it was the water pump/crankshaft tensioner. He put a long screwdriver on it, gave it some pressure and the noise went away.

I wanted to start with the cheapest option first, so I replaced the Aux belt, as it was due any way. (see photos). After fitting the belt, the noise is still there. I can replace the water pump pulley/tensioner, but I want to be sure it is that before I fork out £100 on it.

I noticed a bit of movement coming from the top belt tensioner, so I dunno which to replace next?

Here's the noise/movement of it all:

https://youtu.be/hXPDKo2IfaQ


Thanks!

Hi

I wanted to start with the cheapest option first, so I replaced the Aux belt, as it was due any way. (see photos). After fitting the belt, the noise is still there. I can replace the water pump pulley/tensioner, but I want to be sure it is that

I got a second opinion from a mechanic friend of mine, who said it was the water pump/crankshaft tensioner. He put a long screwdriver on it, gave it some pressure and the noise went away.

I think you got your best confirmation from the mechanic friend that made the noise go away. I couldn't do any better diagnosis than a mechanic who actually put their hands on the car.

Is there any way to tell if this'll actually fit the motor?

https://www.ebay.co.uk/itm/372823359560 ... R6isiffGYQ

I think some of these are electronically controlled? I can't see whether or not there's a connector attached at the top.

THERE ARE 2 TYPES OF FRICTION WHEEL ON THESE MODELS, IF NOT SURE WHICH ONE YOU NEED THEN PLEASE EMAIL US WITH YOUR CAR REG OR CHASSIS / VIN NUMBER FOR COMPATIBILITY CHECK!!!

From the listing, in red text.

You need to contact the seller with the reg to see if it fits.

No disrespect to Devk but this has got to be the dumbest way to save a few drops of fuel!
Put in, an over complicated, badly designed, movable idler wheel to disconnect the water pump from the engine for the few minutes that the engine takes to warm up.
Good one BMW!
How much fuel did it save and how much did the new idler cost?

Sorry, I'll get down off my hobby horse!

It looks to me like the grease has run out of the bearing in the middle of the idler and the bearing has collapsed.
You may be able to pull the entire assembly apart and replace the bearing?
If you can get access to the back side, you might not even have to remove the assembly from the engine.
There is a security torx screw in the center of the idler. That might allow you to remove the idler? I guess you have nothing to loose?