Drilling and Tapping

[Ghia 60]

Previously I have been using the sump drain plug and oil pressure relief valve to read the oil temperatures. As none of the above are exposed to direct oil flow, I am seriously considering this setup.



It is situated in an area exposed to direct oil flow - post the oil pump - as I understand it.

Question: Which metric thread size should I use?
The ID is 21 mm - a 22mm 1.8 would thus not work.
I believe 23mm 1.8 metric tap is hard to come by - I am thus left with a 24mm 1.8 as the smallest size. Would I have enough "flesh" for that size not to jeopardise the strength of the block at that plug.

Has anyone ever attemted this position for the sender?

Your advice would be appreciated...

[Tony Z]

Dont go Metric!!! Use a pipe thread!!!!! BSP!!!!
Gives you a tapered thread that not only aids sealing, but also allows you to adjust the depth of the fitting you are mounting.
Make 100% sure that you are not restricting oil flow into the pump in any way at all!!!!!! Its the suction side and you will suffer if you restrict oil flow. Use a little PTFE tape or Loctite thread seal (literally liquid PTFE tape, with minimal locking charactoristics).
I honestly dont know there the correct place is for the oil temp sender, but I would rather put it on the discharge side of the oil pump.

Dont forget, that because you are on the suction side of the oil pump, you will prob not see any oil leaks even if the fitting is "leaking"... what will happen is you will suck in air, and then bang, your engine is dead.

If you are going to the effort of tapping into the case, you will (should) be stripping the engine right down... rather go full flow and put the sender in the flexible hoses... get an inline sender if you can

Good luck and be careful

[calooker]

It is a good place for the sender if the block is open, as Tonyz states make sure there is no restriction in flow, problem is if the motor is still together and full of oil. If you are running a doghouse cooler then you could get a oil cooler from a Type3 which has a pickup point on it from factory, your sender can be bolted on there, no drilling no mess, wiring will also be hidden and out of the way.

[IMPI]

The SP2 which was the only VW to have a temp gauge from the factory used this location I would also go for pipe thread
Armand