Crazy oil pressure 92 GMC

I'm getting my dad's old 92 GMC Sierra back on the road again and I've got a weird issue with the oil pressure gauge. When first started and while cold, oil pressure pegs the high side, way past the 80psi mark, and does so every time when accelerating, at least until it warms up. I'm hoping it's a gitchy gauge, especially since it seems to have a couple of other electrical gremlins going on as well, plus I've found the same problem with older GMC's on the net.

To determine if it's the gauge or not, can I pick up a cheap one at AZ and connect it to the sender unit? Or if it is a defective sender unit will I still get the same problem? I haven't even found it yet, it's supposed to be at the back of the engine (5.0 aka 305) and it's tighter than the Miata back there. Any ideas or input appreciated.

Oil pressure is good.

My old Chevrolet ('83 Silverao) did the same thing for well over 100,000 miles I never worried about it. YMMV

Heck my '94 Miata does the exact same thing at startup when it is cold.

Now if ya get no oil pressure then you need to worry! ;-)

My 99 miata does this....been wondering if its a problem

Doesn't hit the high side, but will show normal pressure until it warms up, then if I'm idling it drops down, back up when I hit the gas.

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Originally Posted by Rebel

My 99 miata does this....been wondering if its a problem

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If your '99 is all stock you don't really have a "gauge" you got more of a on-off style gauge.

If you want to see it move you may try this - http://www.trackdogracing.com/websit...essure_kit.htm

Have this setup in the wifes 2002 works pretty good.

Cam what oil are you running in that truck?

Does it burn oil or blow smoke?

10W30. No smoke or oil loss. I had to replace the oil pan awhile back after an oil change shop stripped the threads on the drain plug. A persistent little nagging in the back of my head kept saying that maybe some of the RTV I used might have somehow gotten into the oil passages and was the cause of the problem.

My nephew would like to have it but I'm leery of him driving it all the way to Greenville, SC until I can nail this down.

What other electrical issues is it having? Wonder if they are also affecting the gauge. Could be a grounding issue.

Quote:

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If your '99 is all stock you don't really have a "gauge" you got more of a on-off style gauge.

If you want to see it move you may try this - http://www.trackdogracing.com/websit...essure_kit.htm

Have this setup in the wifes 2002 works pretty good

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I'm not exactly stock. Prior owner did some upgrades (tailchaser knows the car), although not sure if he did anything to the oil guage. How would I know? Mine has a very fluid movement up and down, just when I'm at idle it drops back to the low end, when the throttle is open it swings back up.

Who is Tailchaser? Key thing to check to insure the proper oil pressure readings it to be absolutely certain all you shock bolts are torqued correctly!

Kestrel's car may have had the oil pressure gauge mod a bunch of us added this a few years back.

Link to Mod - http://www.quadesl.com/miata_oil.shtml

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Originally Posted by POS Racing

What other electrical issues is it having? Wonder if they are also affecting the gauge. Could be a grounding issue.

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The stereo quit working, one speaker at a time to the point where the only thing it does now is display 1:00 constantly. Headlights weren't working but I found that problem with the switch and fixed it. And then there's what I call the timebomb. Whenever first turned on or when turned off, there's a tap tap tap tap noise that comes from the depths of the heating/ac that I think is a relay. It stops after 10 - 15 seconds.

I'll see about checking my grounds.