Oil pressure sending unit quick question

[RagingPanda]

When installing one do you need a gasket or just use Teflon tape? The reason I asked because I asked the guy that works at Nissan and he you don't need a gasket but when I took out my old one there's a rubber O-ring at the end.

[PapaSmurf2k3]

A lot of the ones they sell now-a-days actually come with thread sealant already applied to the threads. You can try doing it without anything on it, and just start the car up and see if it leaks at all. If it does, remove it again and clean the threads off with alcohol or something and then applying your own thread sealant and/or O-ring.

[lbreevesii]

These things will just about always have at least a minor leak. You actually are NOT supposed to use any sealant on the threads. The thread is a 1/8 bpst which is a tapered thread designed to use the threads themselves to seal. It is designed this way because the sensor uses the threads as its ground. Teflon tape it and(assuming it stays on the threads) it won't work.