78 Oil Pressure Fluxuates

[John S.]

During idle the oil pressure gauge needle jumps around but while driving especially during acceleration it stops and shows a steady reading. Would appreciate any suggestions where to start...bad sending unit possibly.
Thanks,

[Dick W.]

Re: 78 Oil Pressure Fluxuates

Without having the car here to check out, sending unit would be a good guess. Bad connection could also give you funky readings.

[Terry M.]

Re: 78 Oil Pressure Fluxuates

If that were my car, right here -- I would look closely at the electrical connections especially at the sending unit and the connections and wire to the dash. If I found nothing significant I would install a large mechanical gauge in a T right between the engine cylinder case and the oil pressure sending unit. That will quickly tell you if there is a real oil pressure problem or if the on-the-vehicle system is malfunctioning. I tape (duct) the mechanical gauge to the outside of the windshield and take the car for a ride. Note and record cold and warm pressures at low and moderate engine speeds.

What you don't have a mechanical gauge & T? Find a shop that does. I have them because I have had to do this for numerous vehicles -- some with electrical systems, like yours, and some with mechanical systems. If you do much work on your own or others vehicles you will eventually accumulate a large amount of useful, and some not so useful, tools. On the other hand if doing your own work doesn't appeal to you, find a shop that has the tools and the interest to diagnose and fix the problem.