Engine knocking
Turbo Mini Forums

Couldn,t be a piston hitting the head could it ?

Or the cam sprocket loose ?.

I have experienced a knocking that came from the timing cover as a result of fitting a duplex chain set and not bashing out the little dimple on the cover. sounded exactly like your vid.

I have also experienced a knocking coming from the clutch as a result of the pre verto backplate bolts catching the wok. There is also another possability that if the bolts are just a little too long on the engine mounts they will also catch on the flywheel and in extreme cases lock the engine up.

sticking valve?

not sure then, looks like I need a strip down and another check, everything seemed fine, although the main things I didn't check was little end and I know the cam bearings arnt great

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Can't see the cam bearings creating that noise personally. Get a nice big screwdriver with the handle to your ear and go over the engine to pinpoint the noise.

Does the engine have a duplex gear set?

Very unlikely little ends

Oh and what timing cover is on it, a Mini one or a Metro one. The metro cover has a big fat breather can which fouls the fan if its not abused with a hammer

Edited by Sprocket on 1st Feb, 2011.

Its got a mini one on it, but has been modified too clear the timing gear, yes it's duplex, I've had that problem before and was a very different sound.

I'll try the screwdriver listening idea, the sound appears to be coming from the back of the engine, but i'll have to check again, I was going to use a bit of hosepipe to try and determine the noise, but a screwdriver will probably work aswell. The fan is not hitting anything either. It turned over very smoothly by hand and on the starter, only when running does it make the noise, and it varies depending on load. I'll have a listen and try determine the area of the noise and report back tomorrow.

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Maybe Idler gear as Minimole suggested, does it go away your foot on the clutch?

Idler checked with a DTI when building, and stays with the clutch in out, shake it all about, timing case was modified by knocking out the dimpl, aswell as removing the oil splash thing. Then timing plate counter sunk and drum screws used. However, I will not rule it out and will check it, as I could be wrong. I will go over the whole engine and check, whatever it is, it drives fine just very concerning. Especialy as this engine is meant to have a turbo attatched soon.

Will report back tomorow with what I find.

Cheers guys, great help and great suggestions

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Went over it with the screwdriver listening, and it's realy hard to tell where its coming from, can't hear anything from the timing case, but it's hard to get in there without the fan having a bite of my ear, you can hear some noise through the rocker box but I think thats just the tappets, and you can hear the knock through most areas of the block, but it deffinatly seems louder down the back of the engine.

One thing ive noticed, the higher the revs the less you hear it, I'm not sure if this is because induction and exhaust start to take over. You can hear this in the video aswell, a more noticable knock at idle.

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Could it be the head? It does sound almost like valve train somehwere, I ask this because I was thrashing down a dual carridgeway, blipped the throttle on the downshift as I was slowing down, and a big buff of smoke blew out the exhaust, could it maybe be valve guide or something like that? It didn't smoke on acceleration down the dual carridgway just when blipping the throttle.

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probably not going to be this but... is the vaccum hose connected from the dizzy? or any splits?

hope that cam isn't dodgy lol,
take the rocker cover off and start it up, sounds like top end to me, but can't be too sure from the vid...
Think I'd double check the valve clearances if it was me

tried it without the rocker cover, tried 2 sets of rockers, both adjusted correctly. Still knocks, going to try have another listen tomorrow.

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