As you guys know..I built a parted out engine..now I have it semi-running (tuning it) and I put a bolt in this hole (pictured) because it leaks a ton of oil. What went here? And what is the thread? It's not 1/8 npt. I have my own sensors connected to the Autronic so I don't need a sensor there if that was what was there. Picture responses are preferred, but I'll accept a description. Thanks!

Oil pressure sensor

ah..ok. Where was that mounted on the 5sfe? I don't even remember seeing it when I pulled out the engine and took the sensors out.

Can't remember on the 5s. But it was most likely on the head as well. The reason I'm sure this is the oil pressure sensor is due to the fact that I had a fun time tracing a slow leak to it after searching for a source for my gauge

Ugh.. I hate slow leaks. I just pressure washed my trucks engine trying to find one and I still don't see it.

The thread is 1/8 BSPT. It's kind of annoying. Some people have used an NPT bolt or pressure sensor without issue and others have leaks. The sensor on the 5s is on the same X plane but on the front of the block at that same corner. Pretty sure. But I'm going off memory since I pulled the engine and now it's gone haha

I tried an old 1/8 NPT sensor that I have and it wouldn't thread in. If NPT is able to thread in it would have to start out pretty small. My 1/8 NPT sensor wouldn't even start to thread in.

1/8 BSP and 1/8 NPT are very close. the oem sensor is just for the dummy light. you can re-tap it for 1/8 NPT and clean out the hole and screw in your sensor

So is it BSP or BSPT? BSP is straight threads and BSPT is tapered. I thought about that since I have a 1/8 NPT tap. I had to buy a tap to make a bung in my intake piping for an air temp sensor. I just don't want aluminum shavings in my engine. I would rather get a BSPT plug if that's what fits. I'm probably going to drive to the junkyard here today and get the sensor/switch that belongs there and just cut off the wires on the end.

its the tapered thread. you wont get shavings in the engine if you do it carefully. like i said the threads are very very close so you can feed a 1/8 NPT in there to plug it

I bought an adapter for my oil pressure sender. Auto Meter 2269 1/8" NPT to 1/8" BSPT Oil Pressure Metric Adapter

I'd link it but I'm on my phone haha

I plugged it. I found my oil pressure sender and stuck it in there.