Grill block - diesel in summer

[morningglory]

Hi,

I'm in the UK with an old Citroen diesel wondering whether a grill block is worth keeping on all year.

I don't drive the car hard or fast or pull any weight so the engine doesn't get hammered.

The car is from 1993 with mechanical injection and doesn't have OBD or even a temperature gauge.

Is it likely my diesel will overheat? I'm thinking summertime (30 degrees C) in a traffic jam. To be honest I've never even heard the electric radiator fan operate
Any recommendations for cheap/simple aftermarket temperature gauges?
What are the ideal and max temps for a turbo diesel?

Any help much appreciated

Thanks

[user removed]

Install an indicator light in the cooling fan circuit, then block the grille until you see the fan running more than 20% of the time.

regards
mech