Identify this noise please!

[terryp]

Hello
Can you all have a listen to this. Excuse the hunting as the choke is out having just started it.
The noise happens on acceleration

https://www.youtube.com/watch?v=RdK8OBpgFCU

Is it?
Exhaust leak (none obvious)
Pinging
Normal engine noise
Cast manifold

Thanks
Terry

[promotor]

Possible broken valve spring or broken valve shim is my bet.

[terryp]

Thanks for the post
Valve springs are new , lets hope it isn't that.

Terry

[rgh0]

HI Terry
Does the noise change as the engine warms up? My guess is that it is a worn cam follower rocking in the bore but hard to tell on the video. Certainly more noise than normal even when cold.

cheers
Rohan

[terryp]

Rohan
Thanks for replying
I had retarded the timing to exagerate the noise.
At standard timing , its the same but a lot less.
I have now slightly advanced the timing (over spec by a couple of degrees) and its the best its been?
It seems to be only on the first bit of easing on the accerator.
Do you think it could be the mixture being too lean?
It doesn't really change as the engine warms up

Thanks

Terry

[terryp]

Rohan
Just took it for a run up the road it its slightly advanced state and noise is when accerating (All), but not if the car is standing still in the driveway?????

Video here - https://www.youtube.com/watch?v=6eWaZNJYCsA

My wife needs to use the car next Thursday to pick her sister up from teh station in style, I hope its something easy to fix

Terry

[rgh0]

If noise occurs when accelerating but not at idle then it may be what is called "knock" or "pinging" due to too advanced ignition ( or bad fuel not suitable for the compression ratio). if you retard the timing does it go away?

cheers
Rohan

[terryp]

Rohan
The weird thing is, if I retard it , it seems to get worse?

Just taken a picture of a plug

It could be bad fuel? I will fill up and see
Thanks again
Terry

[rgh0]

Hi Terry
If you retard it and the noise gets worse then unlikely to be knock and fuel or ignition related but worth trying some fresh fuel. I presume you have checked for exhaust leaks ? Check for failed engine mounts also.

The videos posted still sound like cam follower noise but hard to tell without being there. Many twin cams I listen to have what I consider excessive cam follower noise so maybe what I hear is what is normal in your engine.

cheers
Rohan

[terryp]

Thanks Rohan, I must admit when I have experienced pinging in the past you can almost feel the power loss.
I have just adjusted as best I can and will drive for a bit and see.
The funny thing is that accerating say up to 3500rpm you hear the noise but sustaining 3500rpm there is no noise???

Thanks again
Terry

[gjz30075]

I had noise similar and always happened on accel or decel. Turns out a few of the cam follower sleeves
had rotated in their bores and the lobes were just nicking the edge of the cutout of the sleeves.

[terryp]

Thanks Greg, how did you fix or did they just sort themselves?

Terry

[Elanconvert]

hi terry

i would have suggested timing chain.....shows you how little I know!!!

have you tried the long screwdriver noise amplification test?

fred

[gjz30075]

Thanks Greg, how did you fix or did they just sort themselves?

Terry

With surgical cleanliness (head on the car), we cut the sleeve cutout slightly larger to allow the lobe to
pass cleanly.

p.s. - To identify this noise, we had to run the car with the cam cover removed. That was the only way
to get close to the noise to identify the problem.

[terryp]

p.s. - To identify this noise, we had to run the car with the cam cover removed. That was the only way
to get close to the noise to identify the problem.

I bet that was messy