Morris Minor Owners Club

Hi all,
Took Jethro to the Brightlingsea car show and fun day today and just as we were turning into the showground a hideous metallic rattling suddenly issued from the front of the car.
Fearing the worst we parked up and lifted the bonnet and....no sign of anything wrong!
On the way home after a brilliant day the damn noise started again and once more after we had arrived and parked up there was no apparent cause for the noise.
It wasn't until I went to look under the front of the car that I noticed the number plate swinging to and fro on its screws and a flick with my finger created the elusive rattle!
Guess what will be getting proper machine screws and nyloc nuts tomorrow!!

The mystery noise is still there at the front of the engine despite fixing the loose number plate.
Took the car out for the first time since September 2nd and the rattling from the engine was exactly the same.
Got home and removed the fan belt and on start up the noise was gone.
The dynamo is a recent replacement and doesn't have any play or slop and turns smoothly so could it be the water pump?
Your thoughts would be greatly appreciated.

Check the bottom pulley, they tend to crack after about 40 or 50 years!

I agree ^^^^ bottom pulley is the likely culprit.

Thanks guys, I will certainly have a look at the bottom pulley when I get a day off from work.
Does the starter dog undo clockwise or anticlockwise viewed from the front?
Also while I'm at it I may replace the water pump as I have a new one and fit an additional fan blade and stiffener.

Anticlockwise, look for a locking washer too.
You should be able to see any cracks without taking it off though.
They tend to go between the rivets first, a bit of gentle levering with a screwdriver will soon tell the tale.

I doubt you will ever need the extra fan, but fit one if you want to.
Only use one 'stiffener' though, I doubt you can get two on!
May as well have the water pump out to check the impellers are ok etc.

Just grab the fan belt both sides of the crank pulley and push and pull as if trying to turn the engine over. As you go back and forth you'll notice any play in the rivets of the front pulley.

I had one come loose. If I recall, the noise always seemed to be on light throttle and idle, never full throttle or on the overrun.

Absolutely no need for an extra fan blade - even in summer - never mind in winter..........

the other option is the engine moving forward under breaking and the fan hitting the radiator... check for any witness marks!

Stripped everything out today- radiator, fan with pulley etc. The bottom pulley although obviously old shows no sign of cracks or splits and there is no play when the pulley is moved back and forth.
Turning the water pump reveals no roughness in the bearings and the same with the dynamo.
The starter dog securing the bottom pulley is on so tight I couldn't see how it is possible to remove it although it does bear a cold chisel mark where someone has persuaded it previously.
It looks like I may have to enlist the services of a mobile mechanic to change the pulley if it is indeed the culprit as I have limited facilities and a bad back!

there is an easy way to undo it...

put a socket on with a breaker bar, turn the engine on the starter, the bar will fly round, hit the chassis leg and undo the bolt...

Use some wood to protect the chassis leg, and make sure the bar is not too long or short (i.e. that it will miss everything or smash in to the inner wing...)#

BUT BE CAREFUL!!!

Then you need to get the pully off... you may need a puller to help you

The breaker bar only want to be an inch or two from the chassis leg, the starter will impart enough into the engine to give a mighty whack to the pulley nut and free it off.

Hang on a bit...... if the pully shows no signs of breaking up,and the test is the pulling back and forth,why are you trying to get it off

You can only see one side of the pulley while it on the engine.
From memory I think the cracked ones I've come across have been cracked on the front, but I could easily be wrong.

A stillson wrench works well on the starter dog too - just wrap a bit of rag round the dog first - and pad the chassis leg. Once the dog is of - the pulley will just slide off by hand - never heard of a tight one ! Quite the opposite unfortunately....

My old Traveller started making a right rattle from under the bonnet, usually when braking. It was the fan blades catching the radiator tank.

bmcecosse wrote:A stillson wrench works well on the starter dog too - just wrap a bit of rag round the dog first - and pad the chassis leg. Once the dog is of - the pulley will just slide off by hand - never heard of a tight one ! Quite the opposite unfortunately....

Ask DavidMiles about the one on his pickup...

StaffsMoggie wrote:My old Traveller started making a right rattle from under the bonnet, usually when braking. It was the fan blades catching the radiator tank.

Checked the fan blade and the paint is unmarked so I guess I can eliminate that as the problem.

Examined the crankshaft pulley closely today and it looked to be perfectly sound.
Fitted brand new water pump, refitted dynamo, radiator and hoses and on startup the engine ran as smooth and quiet as a sewing machine......Result!