I recently replace the Oil Pressure Sending Unit on my 3.6 and it has been working fine. However, recently my gauge is acting funny. With the engine warm, I was idling at a stop light and the pressure gauge died and I got the oil pressure failure indication. A few seconds later after a rev or 2 the gauge popped back up.

It seems to point to "3" when the engine is cold and at idle and when it is warm and at idle it bounces around between 0.5 and 1.5.

Is there something else I should be looking into or might I have gotten a bad sending unit from Pelican?

 

I'd double check the unit you installed - make sure the electrical connections are firmly attached. If so, you may have a failed unit, but I bet that's unlikely.

 

Ken: Why did you change the sender out in the first place? I.E: What was the original symptom?

 

The original problem was the gauge frequently dropping to zero. I replaced it about 300 miles ago and was working fine (I think). On cold start up, it would peg to 5.

 

Sudden dying sure sounds like the sending unit.

 

If you can find the output specs for the oil pressure sender, you could use a multitool (or Durametric if that's a supported data point - I do not know) to see if the values from the sender are normal.

 

I'll have to dig into this more later this week. I'm trying to finish up a detail job on an '85 Ferrari 308 GTS by Wednesday. The sending unit I picked up was not a Porsche OE unit. Do you think that would make a difference?

I've been planning to get the Durametric software but I haven't jumped on it yet. Have to do that soon.

 

Weak or broken oil pressure relief spring?

May be worth pulling it out to take a look.

 

Check the reading on the voltmeter when the oil pressure drops. With all my electrics in order my oil pressure is 2.2 bar at idle; when I had earth cable faults and an idle voltage of 12V to 12.5V my oil pressure used to read