Oil Pressure Sending Unit - Sealant, Teflon Tape or Nothing?

[my12by60]

I have the leaking sending unit out and the new one in hand. The leaking unit had a small band of some sort of white sealant about 6 threads up from beginning of the threads. I assume whatever was smeared on the threads at the factory got forced upward as the sending unit was screwed in and gathered at the top of the threads that went into the engine block.

Have you folks been just screwing in the new unit and relying on the tapered threads to make the seal?

Or have you been using anything on the threads?

[3Q Jay]

I typically put a little something on threads that get wet. last i did was a coolant block drain plug on one of the G50s and I used permatex hi temp thread seal. but it has a cure time of 48-72 hours, not sure if you have that luxury.

[my12by60]

The guys at O'Reilly recommended Permatex white which I believe is exactly what you are noting in your post. Unfortunately, I had to shuttle my kids a few miles from home in the car only a few hours after I inserted the new sending unit. Hopefully things will still set up nicely overnight. I saw no oil on the garage floor after the short drive, which is a good sign as the old sending unit was leaking and spewing all over the place. Accessing the sending unit was quite a pain in the rear end. Removing the old was not the bad, but starting the new one into the threads by hand was tough in that the fingers have very poor access with the oil filter housing and ac line in the way. Anyway, got her done and I hope I get a good seal as I don't want to have to redo it.

[AZhitman]

You can use a little thread sealer (I like the reddish-brown liquid stuff) but keep in mind, it needs to still allow a metal-to-metal contact to allow the unit to ground to the engine (for most sending units).

[my12by60]

The Permatex tube said to leave the bottom couple of threads without any sealer, which I did. No codes popped up when I drove, so I think all is ok. I have the valve cover job set up for next Wednesday. Window tint is getting put on today. Getting close to having this machine looking and running well.

[AZhitman]