Fitting to replace oil pressure sending unit during test

I had no difficulty removing the oil pressure sending unit on my 1998 2.4 liter engine, but am having a devil of a getting the M10 x 1.0 size adapter that came with my oil pressure gauge to fit into the opening (no crossed threads). Does this take a special size fitting?

 

Most oil pressure switches are 1/4 in or 1/8 in NPT, not sure if Toyota's are or not though.

 

Thanks, you are right: 1/8 - 27 NPT

 

The older Toyota`s made in japan did use the metric thread.

I just keep a few metric adapters on hand just in case.

 

Thanks for this information. It may account for the fact that I am not having any luck with the non-metric adapter. The sending unit (male) seems to fit into the 1/8 - 27 NPT adapter (female) just fine, but then, I can't get the male 1/8 - 27 NPT fitting to turn into the sending unit port on the engine block, so maybe it is metric after all.

 

After looking I did need to use an adapter on my 2000 3.4 when I installed a Mechanical oil pressure gauge .

to go from the block to 1/8" NPT