Water drain plugs in 200tdi engine Block?

Haynes manual shows two drain plugs in 200tdi engine block one each side does anyone know what thread the ports are and if it would be possible to fit a temperature probe instead of plug.
Have an additional gauge on my dash which used to be fitted to my 15J Sherpa engine would like to fit sender for it to 200tdi block!
Doug
PS anyone got an engine sitting waiting to be fitted who could check the thread and depth at that point this would be greatly appreciated.

Drain plugs in the engine block? for what?

As it says in title water ie to drain water from engine block

Ok did some more digging and Haynes is as usual wrong only 1 drain plug on alternator side of engine as this video. 200 tdi engine COOLANT drain plug location - YouTube
As the engine block on 200tdi is supposed to be the same as earlier 2.5's with a few mods pulled my 15J engine out from back of garage and sure enough drain plug in same place pulled plug and approx. 22mm depth at this location , plug a very course thread so decided to drill through centre of this plug and tap 1/8th gas think my sender is 1/8th NPT but was previously in an 1/8th gas fitting.
Now fitted to plug with some Loctite pipe thread sealant ready to try into 200tdi block.

Fitted to 200tdi today and it reads 82 degrees as the location is low in the block I expect it is a correct temperature reading but will give a good indication of problems developing.
Not sure what direction water flows through the block!

through top left hand corner of block as looking from front, through block and out through front of head, though cant see a point to fitting another temp device

Gauge was already in my Dash so rather than remove it and blank hole fitted sender