I have a 1983 FB that always reads 0 on the oil pressure gauge. When I start the car the needle shoot’s up then slowly falls back to zero. I took it to a mechanic who said the oil pressure is fine, but I should replace the oil pressure sending unit.

Unfortunately I don’t seem to be able to post a picture. Is it the small little gold piece screwed into the engine block, tucked away below where the oil filter sits?

How do I get access to that? Does anyone have any advice, videos, old forums, etc of people replacing them? I bought a new one on adkins rotary but when it got here it is way bigger than the one that is there.

Thanks in advance, I am new to working on cars so anything is appreciated!

 

Yes - that is it. It's the mushroom looking sending unit.

You can get the factory service manual here. It will show it. Foxed.ca

 

If your car doesn't have the big ungainly pressure sender, then the port may be blocked off OR someone swapped an SA engine into your car. SA engines had no provision for an oil pressure sender.

The oil pressure sender and the coolant temperature sensor (for the gauge) are in close proximity under the oil filter pedestal, you should see two things. You can remove the coolant temp sensor with deepwell socket, you need an open end wrench for the oil pressure sender.

 

It looks like I can post photos now. As you can see it is positioned below a large heat sink that my oil filter is attached to. I’m guessing that is an aftermarket part to help keep oil temperatures cooler. Unfortunately I don’t see an obvious way to remove it temporarily to access the sending unit easier.

 

Yes - that is an aftermarket oil sending unit. It's anyone's guess if it will work with the factory gauge.

It will thread out by removing the water temp wire connection and the oil level sensor wire. Then just us a wrench. Might need a stubby wrench.