Consensus on bouncing oil pressure needle

tailwind22 · 06:18 AM

I know this has been discussed before but is there a consensus on the cause of a bouncing oil pressure needle. Seems like I recall the first thing to try is cleaning the electrical contacts at gauge and sender and second is bad sender. Thoughts? The sender is not a fun project with air conditioning.

dw1 · 07-14-2013, 07:41 AM

I agree with your approach.

I went through this same problem a few months ago, and unfortunately it turned out to be the sensor. As you say, this job is no fun with a/c, but it is not difficult, just time-consuming to disassemble everything one needs to remove to get to the sensor and to reinstall these items.

I also tried to remove the sensor using some of the methods proposed in this forum to minimize the number of parts removed - My advise is to not waste your time, as the connecting pipe and fittings are too fragile to risk. Do it by the book.

DRACO A5OG · DRACO A5OG's Garage

After an AX, my wire broke loose at the sender unit on top, re-soldered, issue solved.

+1, Clean and polish the negative ground cinnection on the gauge as well, it will not hurt.

911SauCy · 911SauCy's Garage

If your car is a '78 like mine, and this is occurring whilst at temp after/during hard acceleration or cornering...the gauge is working perfectly.

You need to perform an Oil Pressure Relief Valve update and install a sump screen.

The needle bouncing is detecting cavitation of the oil due to need for better OPRV spring tension and the sump trying to scavenge sloshing oil.

Otherwise, enjoy your electric endeavors

tailwind22 · 07-14-2013, 02:35 PM

Quote:

Originally Posted by 911SauCy

If your car is a '78 like mine, and this is occurring whilst at temp after/during hard acceleration or cornering...the gauge is working perfectly.

You need to perform an Oil Pressure Relief Valve update and install a sump screen.

The needle bouncing is detecting cavitation of the oil due to need for better OPRV spring tension and the sump trying to scavenge sloshing oil.

Otherwise, enjoy your electric endeavors

So this thought would apply to 78 and older turbo blocks?