Instead of tapping the S52 head for coolant temp sensor...

[aeryk7]

Sounds like a good idea to me.

[dmoffitt]

I think it's a very good idea (in theory, haven't seen it). What might be better is to modify the head when it's off the engine to fit the regular sensor though, rather than having to customize a sensor...

[s52e368]

you c ould get an alum tstat housing and tap it ...
i did

[KangamangusDriver]

I was speaking with one of my friends who recently did the OBD2-OBD1 conversion on a S52 and I asked him what he did about the second coolant temp sensor.

He told me that you can remove the threaded fitting for the coolant hose that cools the the throttle body(one we usually bypass).
-Use this port for the coolant temp sensor.

Once that is done, take the sensor and run a die down the threads to make them smaller. When you get it the correct size you can screw it into the head. no drilling or tapping of the head necessary.

This was tried and tested.

Hope this helps, what do you guys think?