Morris Minor Owners Club

Hello peeps. My heater is the old round type in a SII. When it is cold, the motor screeches but, as it warms up, the screeching stops and all is well.
Any thoughts on why this should be and what to do to?

Most likely dry or failing motor bearings, as it heats up the bearings expand so thats why it will go away.
Ultimately it will be a heater out job to cure it as I am not sure if the bearings are just bushes or roller bearings. From memory you can't get to the bearings with the heater in situ.

But you might be able to get the motor out without disconnecting the hoses? I've only just drained and re-filled the system to fit a new thermostat housing as the old one leaked (rusted through from inside!) so don't really want to lose any more anti-freeze (none of the drain taps work so its a messy pulling off hoses job )

Mine sometimes does it, if you switch it off and on again quickly, using the switch underneath, all goes quiet.

No, having looked at it today in situ, and examining a spare one, I think it will almost certainly have to come out to get at the motor. Well, it doesn't really matter, it was quiet this afternoon and I think its only when temperatures are very low that the screech occurs. And even then, its only for a minute or two. So I can live with it.
However, I shall dismantle, clean up and lubricate the spare one that has been lying at the back off the garage for the last 17 years in case the one in the car ever decides to give up the ghost entirely

Update - I dismantled, cleaned and lubricated the spare heater I had and it works fine. However, it is in a round, black bakelite casing and came from an early 1000, different to my SII, which is a gold colour and different shape.
Would anyoneone know if the motor in this later version is compatable with the SII casing? Just in case...ha ha!

As the motor fits through the center of the heater core I should imagine it will fit but I would do some rough measurements to verify for sure.
I was in a similar position as my rheostat was faulty, I bought a 2nd hand round heater intending on swapping it out but after looking at what was involved I managed to repair the rheostat with a healthy dose of switch cleaner.
At least I have a known good round heater "in stock"

I will take a look to compare the two......sometime