Name that tune?

[thai-wronghorse]

Over the course of the past week my car seems to have developed an annoying resonance from under the bonnet. At first i thought it was the heatshield around the front pipe but after closer inspection and a fresh jubilee clip around it not much changed in sound. Today it appeared to be louder so i thought i get the local exhaust monkeys to check it out on the ramp but they weren't convinced it was the front pipe after all and when they popped the bonnet it seemed to be more prominent from the offside of the engine bay, top end more so. I was advised to see if it was any of the auxiliary belts or pulleys by running it without them fitted momentarily, which I did once home which made absolutely no difference which has now left me stumped tbh as i was convinced it was the front pipe. It was suggested to me that it might be the cambelt or tensioner but i personally changed both of these about a year ago so i really wouldn't have thought it was them.
Would a cracked manifold make a resonating / whirring noise? 


I tried to capture the noise on my phone but it's made my engine sound like a motorcross bike for some odd reason.
http://imageshack.us/photo/my-images/23/2sflvqkitcqudcxupmbgmc.mp4/

[16valver dan]

i get that when downshifting into first like a whirring but then again it could be anything knowing my car it likes to keep me guessing

[tweed]

f**k!
That's no Cambelt tensioner

Have you started it with cam belt cover off?

Sounds internal to me. I would take the rocker off and inspect

[thai-wronghorse]

The cambelt cover was the first thing I took off and I'm inclined to agree that I may well be internal now. 

[tweed]

Could be warn out tappet or something valve related.

[thai-wronghorse]

Could be mate, Its due for an oil change anyway so I'm going to flush it out and refill and see what I'm left with.

[twotwofour]

Mines only an 8v but has made a similar sound in the past. I put some good quality oil in it with cleaners etc in it and the noise stopped. I suspect it was a follower not functioning correctly due to it being caked with years of crud. The cheaper oil not having the detergents in it was just adding to the problem.

[tweed]

How old is the oil and how many miles has it done?

[Screech16v]

Sounds like $hit,bit of top end rattle there mate ,worn followers and cam to me,do the cam lobes look scratched up and discoloured?

[Wayne]

That does not sound healthy, sounds top end related