I found my oil pressure sender, on my 71 Eldorado, not only leaking oil but it was more or less weeping or slightly running out. This happens when I run the car but does not seem to leak when not running. Of course, the loose oil starting burning off and smoking up the engine bay.

I've never replaced one of these and didn't want to start jerking with it before finding out the installation procedure.

I believe these things just screw in with no gasket and appear to need tightning with a pair of pliers or hand tight.

My question is do I just need to replace the thing (hand tight only or use a tool?) or could something else be wrong?

replace it. They're fairly easy to do, and I've seen lots of 'em leak on various engines. Maybe it just needs to be tightened, even. A large wrench should fit on two flat parts of the sender unit, which will allow you to tighten it. Don't use pliers or a vise grip as this could easily cause damage to the sender. If it still leaks after tightening it, try replacing it, and if that's where the leak was from, it'll be gone! Use the white teflon tape around the threads when you put it in as extra insurance against a leak.

Perfect info: exactly what I needed to know. I'll go the replacement route for I'd just probably feel better about doing that.

A deep wall or spark plug type socket should do the trick. I had 3 go bad on my 1968 so far. The oil light would flicker like crazy. :banghead:

I found my oil pressure sender, on my 71 Eldorado, not only leaking oil but it was more or less weeping or slightly running out. This happens when I run the car but does not seem to leak when not running. Of course, the loose oil starting burning off and smoking up the engine bay.

I suspect by now you have replaced the oil sending unit, but I thought I'd tell you the "why/how" these units start leaking..
You will have noticed that the "center" of the unit is a black plastic looking material that is crimped inside a brass or, more commonly, aluminum housing. Over time, the heat of the engine actually causes the "black plastic" to shrink, allowing a gap between it and the crimp.. It's as simple as that.. Fortunately these sending units are cheap and easily obtained..
The Teflon Tape on the threads idea is a great one, just be careful to (1) not allow the tape to cover the hole in the unit (no tape hanging down below the threads), and (2) don't use more tape than necessary.. only a round to 1 1/2 rounds is plenty.. The threads are standard "Pipe Threads", are tapered and the "taper" is what is suppose to "seal" the unit.. excess tightening pressure will only succeed in creating a leak..
Charles.

Thanks, JAG666. I did notice the center of the piece looked vulnerable. I did use the tape, just as you described, and it's been working out great.

I tried using a deep socket but it kept slipping, so I had to round up a specific sending unit socket from NAPA to get it out. It was in there pretty good.

Thanks for the info.

Also, if you use teflon tape, after installation, make sure the OIL light comes on with the key on, engine off. Use too much, and you could lose the ground to turn on the bulb.