I recently managed to get my rebuild running after much confusion and fiddling I have it idling near 1000RPM and one carb piston sits higher (i.e. more air flowing) than the other no matter how I position the idle screws or mixture screws on that carb. So it's a bit lumpy and it doesn't want to respond to throttle jabs without bogging down.

Anyway - theres a squeaky kind of rattle that sounds like it's vibration triggered and it comes and goes at idle and sounds worse as the revs go up. It sounds like it's near the front of the block.

I assumed it was water pump or belt related so I disconnected the belt and ticked it over for 10 seconds or so (so that alternator, water pump and fan were not running) and the noise was still there.

I think I will try and use a stethoscope or something to locate the origin of the noise.

The wierd thing is that it was lovely and quiet under starter motor and would spin and spin - sweetly and cleanly.

Now it's running under it's own power it has a squeak.

I've checked engine mounts and they're all tight as can be. I've listened to the valve train with the oil filler cap off and it seems normal in there.

Could there be a problem with the timing chain / tensioner or something in there?

Any ideas or suggestions would be greatly appreciated.

I would suspect the timing chain tensioner ... ? Use a piece of heater hose as a makeshift stethoscope.

Does anyone know the procedure for checking / setting the tensioner? Come to think of it - it was pretty slack when I put it all back together but just figured it was o.k.

I'm pretty sure the noise is from the front of the block.

Adjusting the tensioner..isn't it tensioned by oil pressure?

I'd need to look at my manual...I've never had to look at the tensioner side of things on an A-series. Gotta love OHV for that.

Chris

Anyhooow I'm not sure how a chain would make such an intermitent noise.

It really is a sqeaky noise like rubbing a few bits of rough metal / plastic together really fast.

I'm just trying to think what would be different about a motor being turned by starter motor v's turning itself under power - 'cos it doesn't make the noise under starter.

Maybe it's just turning too slow under starter to create the problem - or it takes the vibration of a running motor to bring out the noise.

I was wondering if it could be anything off the cam like fuel pump or oil pump - but the noise sounds higher up. If I had to close my eyes an point to the noise I would imagine the sound being just below the head (top of the block) and near to the front.

Does anyone think that a valve on cyl 1 or 2 could be responsible for such a noise - and if so - wouldn't I hear it through the oil filler cap?

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Yes it is...........it is allways a good idea to replace the tensioner when you do a rebuild. They are really cheap .

The squeak could be coming from lots of possibilities........maybe from the oil seal on the timing cover for the crank pully,

Benny.

I was also going to suggest that it could also be the machanical feul pump........they are quite a squeaky pump.

But i see that you already mentioned it

Benny

When I was priming the system on the starter motor (getting oil flowing around) it squeaked heaps from the new oil seal but eventually it settled down. That was a definite rubber on metal squeal.

The noise I have now is squeaky but grating and more a metal vibration squeak (i.e it is coarse in nature) and is the sort of thing you get worried about.

It's similar to having something metal resting next to the block and as if it vibrates quite often.

I can't think of anything on the block that would do that.

it is possible that the plunger in the chain tensioner is in backwards........hard to explain, but im sure you know wanty i mean. The plunger has a ramped/ angled side, so that the chain flows over the tensioner and 90 degree side.

Benny

Does this look backward? It's how it is at the moment. I took this before the timing cover on was put back on.