Morris Minor Owners Club

I put my engine back in the car over the weekend now that all the front end work is done. It has a rattle that wasn't there before - don't know how thats happened, all I did was lift it out on a hoist, place it on the garage floor, de-grease it and lift it bach in again!

Anyway the rattle sounds very like a loose timing chain - is this a common fault with the 1098cc engine or should I be looking elsewhere for the rattle, I removed the fanbelt and ran the engine just in case it was a noisy water pump (unlikely I know) but no change.

Thanks in advance for any comments/advice

Maybe in the lifting out/replacing - the timing case was somehow pressed inwards so it's now contacting the pulleys or chain ? Did your lifting involve rope/sling/chain in that area ?

bmcecosse wrote:Maybe in the lifting out/replacing - the timing case was somehow pressed inwards so it's now contacting the pulleys or chain ? Did your lifing involve rope'sling/chain in that area ?

Thats what I cannot understand - the chain was not near the timing case - it was wrapped round and under the sump - side to side if you know what I mean.

I had a rattle when driving a while ago that sounded exactly like a timing chain but turned out to be the starter motor pinion worn & rattling on its shaft

I have opened up the timing case to check the chain, it looks to be fairly slack but I am not overly familiar with the A series engine so I am not sure if this is normal.

Below is a link to a short video clip showing the slackness of the chain, just wondered if this is excessive or normal.

http://s143.photobucket.com/albums/r159 ... gChain.flv

The video doesn't work for me.

alex_holden wrote:The video doesn't work for me.

Hopefully its working now, the link was wrong before - sorry.

Working ok now- and yes, that does look VERY slack to me. I doubt if simply fitting a new chain and tensioner rings will take up all that slack - may need new sprockets too if they are worn very sharp on the teeth.

Seconded, that chain is knackered.
Take the opportunity to fit a duplex set-up which will last a LOT longer.

Duplex is really not necessary with a standard cam and standard valve springs. However - fitting the later Mini tensioner with single row chain does make for a nice quiet chain!

How does the chain tensioner work on the A series engine? (I am more used the Opel's CIH engine with a long chain and tensioning pad!) Looking at the workshop manual it refers to tensioning rings but I don't understand how the rings work to tension the chain.

The rings are supposed to lift the chain slightly to reduce slack. the later mini/metro type has a proper tensioning pad which will need a different cover & some extra holes drilled in the front plate to mount it

The answer is that they hardly work at all
When they are young and springy they will take some slack out of the chain that isn't being pulled on so about a quarter of the pulley circumference.
I don't agree that the standard Minor doesn't need the duplex chain.
It is a well known issue with these engines which can be ameliorated quite easily with the duplex set up without having to do any more dismantling than you would just to replace the old chain.

Really -duplex is an overkill on a standard engine - the Mini single row chain with proper tensioner was the answer used by Rover ! It is quiet. The duplex is stronger but not necessarily quieter. Only one small blind hole has to be drilled into the front plate to fit it. But - it's no great hasle to fit duplex although you do have to countersink the two bolt holes - and make sure tha swarf doesn't get into the engine !

You'd have to try pretty hard to get it in there Small possibility of getting some in the timing gear, I guess

I realise the standard engine doesn't need the extra strength of the duplex chain but it does mean that the load is shared across "two" chains and so wear is reduced.
Also it is an easy upgrade with the engine in place.
What warning do you get when the simplex chain is worn out if there is a tensioner fitted?
I assume it wears just as fast as it would without a tensioner.

No special warning - but doesn't seem to be a problem on Minis - I've never heard of a broken/dropped timing chain on a Mini - although surprisingly there have been one or two on here with Minors in recent times. BTW - all (4 at the moment) my A series engines have Duplex!

Thought I should post an update. I fitted a new timing chain and gear wheels, the engine is now smooth and quiet.

Thanks everyone for your help on this.

And a correction to my original post - I thought the engine only started making the rattling noise after I refitted it. A friend who came with me to collect the Minor and transport it back, had noticed the noise at that time, I had not! so removing and replacing the engine is not relevant!

Good news - hope you also fitted new 'tensioner rings' to the cam sprocket ?

My new engine has double valve springs - should I fit a duplex chain if this has not been done?