[marco246]

Hi, All,

There are two electrical oil sending units on the car, one for the low oil pressure idiot light and one for the oil pressure gauge. One of the senders is located atop the oil filter housing on the header side of the engine. Where is the other? And which is which? The wiring diagram in the owner's manual is not much help. . . .

 

[justcallmefred]

senders-

The oil pressure sender is much bigger than the temp. sender and goes on the intake side of the block fairly high and near the back. It's about 1 5/8" in diam. and 1 3/4" tall.

 

[ShadeTree]

I grabbed this photo from elsewhere on the BB:

 

[Andrew Stevens]

Note that there are different senders available depending upon the brand of the gauges in your car, either Veglia or Jaeger - you need the correct sender to match the brand of gauges as they will not read correctly otherwise...

 

[marco246]

Thanks Fred and Andrew,

Looks like the oil pressure sending unit is going to be a real beeyotch to replace. I can get a pair of vise grips on it, head on, but can't exert enough torque to break it loose. Think I'm going to have to take off the intake manifold (with Spica mechanicals) to be able to replace it.

This has turned out to be a bigger job than I'd envisioned. I'm going to kick the can down the road for a while. . . .

Thanks again.

 

[justcallmefred]

Take sender out-

You can't see it but a 14mm wrench will take the sender out, it may have to be a thin one (my long pattern snap-on works) Right behind the "body" of the sender close to the block, it's a pipe thread (tapered) so it should not be that tight to remove.

 

[Andrew]

In my experience the gauge sender, by the starter, is not a pipe thread, but rather a straight thread that depends on a copper washer to seal. The light sender on the exhaust side is a pipe thread.
Andrew

 

[marco246]

Yeah, I have a replacement oil pressure sender and see that it takes a 14 mm wrench on the engine end of the sender. It also comes with a washer. There are only two ways to get at the sender with a 14 mm wrench: from above and from the right (where the intake manifold interferes). Guess I need to find a longer wrench and try to get it from the top of the engine.

 

[Andrew]

It's tough to get in there but can be done. Some early sending units had a 17mm wrench flat.
For your safety, unhook the battery in case you hit the starter hot connection with a wrench.
Andrew

 

[james2000]

Yeah, I have a replacement oil pressure sender and see that it takes a 14 mm wrench on the engine end of the sender. It also comes with a washer. There are only two ways to get at the sender with a 14 mm wrench: from above and from the right (where the intake manifold interferes). Guess I need to find a longer wrench and try to get it from the top of the engine.

I had a similar problem with another car. Not enough room to move the wrench. I finally used a crow-foot wrench and worked perfectly.
Good luck.James