Thanks for your response.

I've read numerous posts hereon which state different scenarios for the operation of those fans. I recall more than one which stated that one of the fans comes on at 105C and the other at 130C. The 130C obviously seems high though.

I'm trying to figure out if I have something faulty which is causing the temps in my M103 to rise above 100C. I recently put a new OE VDO temperature sensor in the engine. That same day I had also changed the distributor rotor, cap and wires. I also changed the valve and timing cover gaskets.

It may be purely coincidental, but that evening was when I first noticed the engine temp rise above 100C. It had normally hovered around 80C. It seemed that the fan clutch wasn't operating properly, so I put a new Behr clutch in.

The temp hasn't gone as high with the new fan clutch in, but it still goes up to about 105C or so. At that point the right hand auxiliary/radiator fan kicks on and lowers the temp.

I just don't know how much of what I've described is normal.