Engine noise -any ideas? (Video)

[thejones's]

Out 1600 sp has suddenly developed a rattle/light knocking. Worse ar idle/low revs, but not really there at speed. We should be leaving for south France in less than a fortnight.

I've checked valve clearances, head tightness, removed fan belt to fine out dyno and fan. I think it may be cam bearing or lifter???

Any suggestions before I pull it apart?.

http://i695.photobucket.com/albums/vv313/hanpug25/ddcb00f7581027538e8969fc559baf95.mp4" onclick="window.open(this.href);return false;

 

[Paul Weeding]

You're gonna have to dive in and get it pulled down...

 

[Trikky2]

I agree. It has to come out and be dismantled if you can't isolate where it's coming from.

The rattle is too fast to be a single lifter, pushrod, rocker or valve.

It sounds more like slap in the cam drive cog for instance bit it could also be a loose flywheel. It's hard to tell from a video just exactly where the noise is coming from.

(The last time I heard one making a strange rattling noise I found the crankshaft had snapped Lol. )

 

[Johnny69]

There's. John Muir web page on the web somewhere that lets you listen to what different engine problems sound like - you could try that to see if you recognise anything first? Good luck with it - it does sound like it could be a loose flywheel or something broken inside the case.

 

[thejones's]

Cheers for the tips. Pulled it out/apart today and all I could find was a loose cam drive gear -looks like loose rivets. See vid below. Could this be the cause???

http://i695.photobucket.com/albums/vv313/hanpug25/e00f08a29d73f4ca86dac3e681f4d3d4.mp4" onclick="window.open(this.href);return false;

http://i695.photobucket.com/albums/vv313/hanpug25/ee947d4f91941b05da5e151fc9dab60e.mp4" onclick="window.open(this.href);return false;

Cheers.

 

[KateLovesPurple]

Sounds likely! I had similar on my fastback engine some years ago, it had a bolt on adjustable gear that had started to come loose and the bolts were smacking the back of the oil pump case!

 

[dasteel]

I had the same loose cam gear on my new engine last year. It was quiet when under load and like a bag of nails at idle.

 

[Paul Weeding]

This is what would've happened, had you ignored said noise :shock:

 

[thejones's]

Ouch!

overhaul's going ok so far considering its my 1st aircooled rebuild. Barrels and heads should be going back on after work. Needs to be ready for a trip to France on Monday - doing a twinport conversion at the same time - not my original plan, but we had a cracked head. Managed to get all the twinport bits from Tatton park for £85!

 

[Trikky2]

Good to hear its going well. You should make your schedule easily and have time to do a few test runs before going by the sound of it.

 

[Tristan71]

You got the head tins too rite also just a quick one while the engines out take the oil cooler off fill it full of jizer or petrol and give it a good clean same with the oil relief valves at the bottom of the case they often get forgotten

 

[thejones's]

Good to hear its going well. You should make your schedule easily and have time to do a few test runs before going by the sound of it.

Cheers fella. May be seeing you in a couple of weeks if it all blows up!

 

[thejones's]

You got the head tins too rite also just a quick one while the engines out take the oil cooler off fill it full of jizer or petrol and give it a good clean same with the oil relief valves at the bottom of the case they often get forgotten

Yeah, got the head tins. Had to faff about tonight cutting head studs and drilling out holes for the bigger oil cooler pins. TBH, I've not had the relief valve out -is there just the one? It's a 'variant' case according to the lad at Limebug.

On another point, my barrels have a metal shim around the bottom where the paper gasket goes. Do I need to keep these, there more like shims/spacers than gaskets.

Cheers

 

[Tristan71]

The metal shims set the compression ratio normally as for the relief valve on some cases there's one some there's two it's probly a universal case