erratic oil pressure

[Davz912/911]

Hello,

My oil pressure is all over the place, its a '67 with a '70 2.2 in it. A week ago all was fine, rev engine, oil pressure goes up, ranging from 20psi to 100.
now it goes up to 40, down to 20, jumps to 100 etc. So I figure new sending unit, install that last night, same thing. Now I figure gauge, went down to local
auto parts store and by a mechanical gauge, hook it up, same thing. CRAP!!!

So I pull out the old manual, no schematic of oil system, pulled out the Anderson engine book, and see these engines have two oil pressure relief valves. Is it possible the springs are weak, or maybe the pistons are sticking giving me these readings? Can it be my oil pump is on its way to failure? Or
"gasp" is it time for a rebuild?

Any ideas will be appreciated

Dave

[kissov356]

Check you grounds.

[WCB4]

Ten pounds of oil pressure for every 1000 RPM, more is allways better though. Was it a good quality mechanical gage? Ran into the sanething last spring when I first got the 71 out. One day all was fine the next almost no oil pressure to speak of. Allmost **** my self. Installed a VDO mech pressure gage all was well. Turned out to be, You gussed it a bad ground. Ya just gotta love the wiring on these old cars!
Regards, Bill

[Davz912/911]

the mechanical gauge was a cheap Kragen auto parts special. I know I know!
but since it gave close to the same readings I figured it was close. As for the grounds....I reseated the ones on the gauge itself, The one from the trans. to body looked ok last time I was under the car. I'll have to check were the daisy chain ends from the instrument pods. Now that I'm thinking about it, this started sometime after I pulled all the gauges to clean the glasses. I may have desturbed something.

I'm also thinking I should check the sump screen. When I changed the oil for the first time (I've only had the car a month or two) I didn't pull the sump plate to check the screen. It could be buggered up I suppose.

I'll let you know.

[rick2]

Be carefull of the one on the trans. It may look fine but the resistance builds over the years and can cause your alt to do all the grounding.
Rick

[Davz912/911]

Ahh...that warm and fuzzy feeling of mashing on the throttle. taking a glance down, and seeing your oil pressure climbing steady to triple digits!

Found the grounding point behind the defroster tube, got almost a full turn on it. Nice to see a solid brass grounding point, really speaks of the quality of our automobiles.

Thanks again!

Dave