Hi everyone, does anybody know the size of a bolt I can use to block the hole where my Tempature sensor is, I don't want to loose all my coolant while trying to figure out the adapters thingy when I'll be installing an electrical temp gauge.

 

Whatever you do, don't put a bolt in there. It's a 1/8 NPT pipe thread, far different from any bolt. Your new temp guage probably uses the same thread.

 

I'm fairly sure it's not NPT, I think it's British Standard Pipe Thread/Taper same size, but one TPI off I believe it's 27 instead of the 28 on the NPT.

 

The pipe thread on the temperature sensor can be random at times.

As Nismo said, sometimes it is 1/8" BSPT. Early engines tend to be BSPT.

Later engines are a straight metric pipe thread.

Sometimes it's been hacked up so much it's now 1/8" NPT.

 

I've used my 1/8NPT27 tap several times with no issues.

 

Yes...The thread is close enough to 1/8 NPT that it will conform.