strange tappet noise

Post by **mu0u207b** » Fri Nov 11, 2005 1:45 pm

Hi there, heres another problem with the old moggie. Over the summer i fitted a new cylinder head, new water pump and new rocker assembly as i had problems with my original unleaded cylinder head. All seemed fine all but a very slight rattling noise which i assumed to be the water pump not located properly, this seemed to die down. Weeks later i had to replace my duplex timing chain for another one as this was starting to wip slightly. This was fine until i had to do a long motorway journey which at the end the engine was making a noise very much like a porly adjusted tappet. I readjusted all the tappets but the noise was still present. The noise seems to be more profound once the engine has warmed up and sound very much like a poorly adjusted tappet. Any ideas?

Post by **Willie** » Fri Nov 11, 2005 1:57 pm

A good way of proving if the noise is from the tappet/rocker gear is to have
the cover off and the engine on a slow tickover and then insert a 10thou"
feeler blade under each rocker in turn. You will soon find out if a tappet
is the culprit. You will get some oil spatter if you do this so be prepared.
It is useful to trace noise by using a long rod or screwdriver with your ear to one end and trying it on various engine areas.

Post by **paulk** » Fri Nov 11, 2005 2:50 pm

[/quote]It is useful to trace noise by using a long rod or screwdriver with your ear to one end and trying it on various engine areas.[/quote]

Very succesful this, but people do give you funny looks if you do it in Asda car park.

Post by **bmcecosse** » Fri Nov 11, 2005 4:33 pm

Could be a cam follower - why did you have to replace the duplex chain ? they usually last a very long time. And why do you have duplex anyway - normally only fitted with a 'performance' camshaft and/or double valve springs.

Post by **Matt** » Fri Nov 11, 2005 4:35 pm

to get rid of the timing chain noise prehaps?

Post by **TerryG** » Fri Nov 11, 2005 4:36 pm

I had one fitted to my mog when the chain started getting noisy as i was told a duplex kit would not need changing again

Post by **Willie** » Fri Nov 11, 2005 6:07 pm

One of the characteristics of the A series is a nasty timing chain clatter after
only a short time. The duplex conversion is cheap,easy to do,and solves the
problem.

Post by **bmcecosse** » Fri Nov 11, 2005 7:11 pm

Yes - but I asked why the chain had to be renewed - he did not say changing TOO a duplex chain, although that would make more sense. Also when going to duplex you must c/sink the two wee bolts on the front plate - if this not done (or bolts coming loose) this could be source of the noise!!

Post by **RogerRust** » Fri Nov 11, 2005 7:32 pm

bmcecosse wrote:you must c/sink the two wee bolts on the front plate - if this not done (or bolts coming loose) this could be source of the noise!!

ahh I'll remember that I met someone the other week who had gone back to single chain because it made so much noise. Are the wee fellows obvious?

Post by **mu0u207b** » Fri Nov 11, 2005 10:09 pm

i initially changed from a single chain to a double chain because i got fed up with the small period before the chain started whipping again. The first time when i changed from a single to the duplex i didnt to a great job of counter sinking the two little screw where the tolerance between chain and screw head was a little too fine. I had to change the chain again after roughly 10000 miles or two years of running where there was anoticeable increase of chain noise. This time i made a proper job of countersinking the screw heads but the chain it self was a complete bitch to get on. It fitted fine over the crank shaft but the addition tension in the chain made it REALLY difficult to fit over the camshaft,. It took a real bashing to fit it over.
Could any of the noises be due to a worn cam shaft which was magnified by a new more tensioned chain.

Post by **mu0u207b** » Sat Nov 12, 2005 12:37 pm

Hi guys. More problems now. The tappet noise which i believe is not a loose tappet(s) is now accompanied by a squeeking noise. Now i initially through that this was a failing or poorly oiled dynamo bearing. I have now disregarded this now as i have removed the fan belt and the noise is still present. The noise seems to be coming from the bottom front end of the engine and literally sqeeks like a dry dynamo bearing. I have changed the bigend and small end bearings, there is no rumbling on start up. The noise seems to be coming from the timing chain cover area. Could this be a failing camshaft/bearing?

Post by **bmcecosse** » Sat Nov 12, 2005 8:00 pm

I don't understand why the duplex chain would be tight to go on - a 'real bashing' is definitely not normal !! The two sprockets slide on beutifully - but you must keep them in line - and you must make sure the key (particularly on the cam) stays in place. I suspect something is going wrong in there - and suggest you pop the timing cover off for a look see asap. Don't understand your comment re- small end bearings - the A series engines don't have any ! The gudgeon pin is clamped in the con rod - and runs directly in the Aluminium piston.

Post by **mu0u207b** » Sat Nov 12, 2005 8:41 pm

Sorry meant the con rod bearings. I was a little puzzled at the time when putting the chain on. It took me nearly an hour to do so. Normally they go on really sweetly. Both sprockets were lines up exactly as was the key. It seemed that the chain was approx 0.5-1mm too tight. It was also a different make of chain other than the one that had came off.