Big ends for '86 B200E

Post by **foggyjames** » 27 Jun 2005 12:33 am

I'll take my feeler gauge back with me, and see how I get on. If this cover gasket has failed too, I'll not be happy!

cheers

James

Post by **pettaw** » 07 Jul 2005 05:19 pm

pettaw wrote: I would try and get a recording but I don't think it would be picked up. Other than that the car runs great. No oil leaks/water loss and has now done 700 miles trouble free.

I managed to get a recording of it, although not too clear hopefully it might jog somebody's brain.

BTW all I'm doing is putting the revs up and down, clutch depressed, so no load on the engine.

http://www.pettaw.dsl.pipex.com/360noise.mp3

Post by **huskyracer** » 07 Jul 2005 07:46 pm

Cant realy tell much from the recording, there is a noise a bit like a fan belt (not squealing, a sort of rubbery scraping noise) that is lower in speed than the engine, is that the noise?

Post by **pettaw** » 07 Jul 2005 08:30 pm

Its the faint vibraty noise that comes in intermittantly as I raise and lower the revs past the 'sweet spot' If I hold the revs steady enough, you can get it to resonate constantly.

Post by **pettaw** » 07 Jul 2005 08:38 pm

I've tried to dial out the other engine noises to try and focus in on exactly the noise I mean.

http://www.pettaw.dsl.pipex.com/360noisemod.mp3

Post by **foggyjames** » 17 Jul 2005 03:15 am

Definitely sounds like it's at less than normal engine speed, which narrows it down to something related to the camshaft and cambelt train, or something on the auxilliary belt 'circuit'. It could even be something to do with the viscous coupled fan? It sounds to me like a metallic grinding sound...something rubbing on something?

cheers

James

Post by **pettaw** » 17 Jul 2005 10:45 am

It sounds like a belty noise doesn't it? Unfortunately it can't be because I took all the belts off and the noise is still there.

Another person on another forum suggested the harmonic balancer (otherwise known as the crank pulley) had failed so I replaced it along with the engine mounts. The engine is definitely smoother, but that noise is still there annoying enough. Tappets are all smooth now, well, as smooth as they ever get.

Post by **foggyjames** » 17 Jul 2005 12:47 pm

Have you checked the fan shroud and the cambelt housing for signs of rubbing?

cheers

James

Post by **petefarrell360** » 17 Jul 2005 02:59 pm

I'd agree, having heard it in person, that it sounds like a belt rub of some sort, and as Andy said, he's removed belts, investigated thoroughly and still it's there. Just hope there's nothing actually doing any damage after all of your hard work. It's so hard to track it down to a point though, as you've got so much noise, then the sound is bouncing off of everything else in the engine bay, fooling you of it's origin. I know you said you'd had a stethoscope on it, which is a good idea, but you couldn't find anything with that, which can only a be a good sign from the internal point of view.
Pete

Post by **pettaw** » 17 Jul 2005 06:01 pm

I'm fairly well convinced its a harmonics/resonance issue. I'm half wishing I had the machine shop balance the crank/rods/pistons up now! If that IS the case it'll really want pulling apart again. My parents won't be too pleased!

Post by **foggyjames** » 17 Jul 2005 07:44 pm

It might be worth trying using a crow bar (is that the right spelling?) as a 'listening stick'....stick it against bits of the engine to listen for the seat of the noise. I'd be somewhat surprised if it is something internal, but who knows.

cheers

James

Post by **pettaw** » 17 Jul 2005 08:49 pm

I already have a mechanics stethoscope and I can't hear anything mechanical, but I also can't pinpoint the noise.

Post by **foggyjames** » 17 Jul 2005 11:54 pm

Ah.....cool!

I'm all out of advice without being able to listen to it in person

cheers

James

Post by **huskyracer** » 27 Jul 2005 07:50 pm

Dude, I just had a brain wave, I might be hopelessly wrong, but could the cam belt be a bit on the tight side?

Post by **huskyracer** » 27 Jul 2005 07:56 pm

The harmonics think is unlikely, I have much personal experience with throwing engines together from piles of random bits, quite often from diffarent manufacturers, with no balancing and never had a problem. as far as I can see the only bit youv'e changed that would affect this is the rods and pistons and that is quite unlikely to cause a problem as most of the weight of these is reciprocating rather than rotating