Horrendous Knocking Noise

Hey guys, used my car for a wedding yesterday and after the day had ended I noticed an extra amount of noise coming from the engine bay..

Pulled off a few covers today to take a look and it seems as tho it's coming from the fan pulley area, it sounds horrendous like something is knocking...

If I rev the engine the noise goes, it's only at idle this noise is present..

Check this video? Can anyone help, I'm seriously concerned it might be fatal!!

https://www.dropbox.com/s/id1phuvug547rjp/2014-02-22 13.14.19.mov

You don't say what engine, but my crystal ball suggests the crank pully vibration damper.

Pull the aux belt off and rotate some bits, water pump, alternator etc. Run the car without the aux belt and see if the noise is still there.

It sounds more like a rattle than a knock to me, perhaps the water pump is falling apart inside?

I've had the fan and belt off this afternoon.

The noise is present with the belt there but as soon as u take it off it stops.

I'm fearing the worst that it is the crank damper pulley... But when I tried to move it with 2 hands it wouldn't budge, the only pulley with any real backwards/forwards movement is the ace one.

How do I know for sure if the crank pulley is the one?

Fowlersrs said:

I've had the fan and belt off this afternoon.

The noise is present with the belt there but as soon as u take it off it stops.

I'm fearing the worst that it is the crank damper pulley... But when I tried to move it with 2 hands it wouldn't budge, the only pulley with any real backwards/forwards movement is the ace one.

How do I know for sure if the crank pulley is the one?

Click to expand...

use a screwdriver as a stethoscopee whilst its running carefully put one end to your ear and the other end on suspect pulley, you should be able to pinpoint the noise

johnlad said:

use a screwdriver as a stethoscopee whilst its running carefully put one end to your ear and the other end on suspect pulley, you should be able to pinpoint the noise

Click to expand...

Obviously not on the pulley itself, on the housing just by the pulley!

Fowlersrs said:

I've had the fan and belt off this afternoon.

The noise is present with the belt there but as soon as u take it off it stops.

I'm fearing the worst that it is the crank damper pulley... But when I tried to move it with 2 hands it wouldn't budge, the only pulley with any real backwards/forwards movement is the ace one.

How do I know for sure if the crank pulley is the one?

Click to expand...

use a screwdriver as a stethoscopee whilst its running carefully put one end to your ear and the other end on suspect pulley, you should be able to pinpoint the noise

Fowlersrs said:

I've had the fan and belt off this afternoon.

The noise is present with the belt there but as soon as u take it off it stops.

I'm fearing the worst that it is the crank damper pulley... But when I tried to move it with 2 hands it wouldn't budge, the only pulley with any real backwards/forwards movement is the ace one.

How do I know for sure if the crank pulley is the one?

Click to expand...

I would be very surprised if it was the crank pulley, they don't usually make that sort of noise when they are rough. Could be wrong though.

But do as the others said with a long screwdriver or similar to see if you can pinpoint the sound. And just spin the tensioner, the water pump, the alternator and whatever else you can with the belt off, see what feels or sounds rough.

http://m.youtube.com/watch?v=kNETY2Q5u4Q
See the tube link.
HTH.

Your symptoms are classic of crank pulley however play in any pulley is obviously undesirable. How much play in the ace pulley are we talking? Enough to cause such a horrible noise....with this being one of the most accessible i would have thought it would be easy to check with engine running. If nothing else isloose theres a good chance the water pump is your culprit. As this is piggy backed off the PAS pump it is not accessible from the front of the engine and may be your culprit........any other reason to suspect this...water loss for example?

robhew86 said:

http://m.youtube.com/watch?v=kNETY2Q5u4Q
See the tube link.
HTH.

Click to expand...

I stand totally corrected, they sound exactly like that when then are rough.

I'll get my coat...