I have a '85 244 and had a similar problem. Whenever I would take off and shift into second gear the needle would shoot straight into the red and as I let off the gas it would settle down. Here's where I separate from the experts.

First thing I did was check the wiring to the coolant temp sensor. I believe on your B230F it's below the intake manifold. It should have a yellow wire. There are two sensors, one is for the computer I think and the other one is for the temp gauge. In any case, check to make sure that the wiring is not frayed. What happened to me was that the wire was worn and would ground out on the intake manifold. There are a bunch of wires in the engine wiring harness that travel through the intake manifold and in that area. Upon inspection I found a bunch of other wires that were also in bad shape and needed replacing, particularly the alternator and oil pressure light wires.

Thought this might be a good place to start before you disassemble your dashboard.

Good luck!

Orest '85 244 179k