afaik a broken variator will not damage the engine but you may get diesel-like sound coming from the engine, especially during cold starts. You will also lose some power.
This is a common fault is is well documented in this forum. Do a search for 'variator'.
The diesel noise is caused by a fault in the variator itself. If the solenoid valve that controls it fails then you will get rough running at idle and engine stalling due to the valve timing being set for high engine speeds (the valve is biased to the high speed position and is energised to switch to low speed).
On the old forum, there was a post about changing the variator solenoid valve curing a stalling problem. Something about different suppliers for the old and new valves IIRC.
I solved the stalling problem on my 147 by replacing the entire vehicle with a 156 SW!
"Diesel - Green Fuel of the Future" - Lucas Diesel Systems slogan circa 1992