engine and drivetrain Oil pressure light on intermittently, randomly.

[evoldog]

1974 2002, daily driver.

Searched the forums quite a bit, no dice, unless I'm missing something.

My oil pressure "idiot light" is coming on randomly. Sometimes it stays on. Sometimes it stays off. Sometimes it flickers. Sometimes it goes away over 1000 RPM.

Oil is staying in the engine. Engine is not overheating or making weird noises.

Am I right to suspect the oil pressure sender?

I'm new to working on cars, so my apologies if I'm dense about this. Is this how I should go about it?

1. Buy oil pressure tester kit? Like this?

2. How the hell do I use one?

3. If the pressure is good, buy a replacement sender? On bavauto.com I see part 360 023. $32. But I have to also buy part 240 043 for $36 more?

I read in the forums about making sure I buy the right sender, so any help in that department would be appreciated. Thanks!

[evoldog]

Or maybe I should be looking for one of these, with either coarse thread or fine thread.

[Mike Self]

The sender grounds through its mounting threads...hopefully it wasn't installed with pipe dope or Teflon tape. Pull the unit and check the threads for cleanliness. Also check the push-on terminal to make sure it fastens tightly to the male terminal on the sender. Loose = randomly flickering oil light.

Senders are cheap--get a replacement and install it. It's good to have a spare anyway, as when the sender fails (and they do) you will lose your oil in pretty quick order and really make a mess in the engine room.

cheers

mike

PS--get a gauge with a separate terminal for the warning light--much better than just an idiot light.

[Hans]

There are two styles of senders - with different threads. You could try that first. I was trying to think of how loose connection at sender would cause problem - seems to me the light comes on when line is grounded by switch. Unless something is touching the terminal. Oil pressure tester looks interesting - choose the correct fitting, screw into sender hole, hook up gauge, start engine with someone watching under hood - and prob holding rag around fitting just in case. No need to rev engine - fast idle will tell you if pressure is steady.

[evoldog]

Hey I think I found the oil pressure sender!! Is this it? It looks oily.

Can I buy one of these at Napa Auto Parts?

[Timmer]

That's it; 9 out of 10 times they leak oil at the top of the unit, looks like it your case as well; NAPA should have one

Tim

[c.d.iesel]

i guess your motor runs better without VACUUM ADVANCE ?

[Hans]

You certainly appear to have a leak there. Is that wire connected to the sender tab? It appears to be off in the pic. Even if it is on, is it possible it makes contact with vacuum pipe?? Perhaps a bit specialized for Napa, but you may need to take old one with you to get correct threads - unless you can determine that some other way (thread gauge for example)