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post #1 of 12 (permalink) Old 02-04-2013, 05:19 PM Thread Starter
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Oil Pressure problem on 1984 Vette

Hey guys, i recently replaced my oil pan gaskets and changed the oil too. On my way to town i noticed that when i accelerate my oil pressure drops from 80 to 49. before i changed the oil it only dropped 80-66, when it was warm and was stopped(like at a stop light)

My engine has about 163,xxx miles and i use 10w-30, is this something i should be worried about?
Thanks!
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post #2 of 12 (permalink) Old 02-05-2013, 03:45 AM
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thats plenty oil pressure ,especially on an old motor.. GM says only 8psi is necessary at hot idle ..is the oil temp going up when the pressure falls off?. you were careful not to dislodge the pump pick-up tube while installing the pan?
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post #3 of 12 (permalink) Old 02-05-2013, 07:02 AM Thread Starter
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i haven't checked if the Temp rises, but isn't the pick-up bolted on? is it easy to dislodge?
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post #4 of 12 (permalink) Old 02-05-2013, 09:28 AM
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this is the pickup tube http://www.summitracing.com/parts/me...ette/year/1984 ..it is press fitted in the pump , no bolts .it can twist or come out ....most of us tack weld the tube to the pump to prevent that, when we build performance engines..., .. result is, on acceleration,or hard braking or cornering, it is not down deep enough in the oil pan, and pressure falls ..not saying thats definitely whats going on here, you still have plenty oil pressure

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post #5 of 12 (permalink) Old 02-05-2013, 10:25 AM
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Originally Posted by xCrossFirex View Post
i haven't checked if the Temp rises, but isn't the pick-up bolted on? is it easy to dislodge?

The pickup tube is pressed into the oil pump and should remain tight unless the pump has been changed at some time and the original pickup was used over again. The best thing to do any time you have (or suspect) oil pressure problems is to check it with a mechanical gauge. You can easily tee into the oil pressure galley on the left side of the block and then run a hose into your cabin with a mechanical gauge on the end of it. Then with two gauges you can compare them. The mechanical gauge should be the more accurate of the two.

And as fish said, always tack a new pickup tube to the pump with a MIG welder so there's no chance of it ever loosening.
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post #6 of 12 (permalink) Old 02-07-2013, 08:59 AM Thread Starter
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Thanks guys for help!! i checked to see if the temp changes but only by 2 degrees and its slow!, also the oil pressure is kinda wild, it will go from reading 80 at idle to 50 to 49 now(back and forth) during idle and acceleration, it has to be the pick up tube right? all i did was change the oil pan gaskets and oil and filter i see no leaks? before the change it was normal 80 and when it was warm it would just drop to 68 when doing a complete stop. Toobroke, i tried to find the oil press galley but no luck..is behind the headers? i could be over looking it.
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post #7 of 12 (permalink) Old 02-09-2013, 04:15 PM
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Toobroke, i tried to find the oil press galley but no luck..is behind the headers? i could be over looking it.

It's at the rear left side of the block right above the oil filter
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post #8 of 12 (permalink) Old 02-11-2013, 01:57 AM
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also the oil pressure is kinda wild, it will go from reading 80 at idle to 50 to 49 now(back and forth) during idle and acceleration, it has to be the pick up tube right?
I suspect the sender unit for the gauge ( or the gauge) is faulty.
80 psi is way high for any SBC , no way is a motor with your mileage going to have that pressure.
My new race motors with HP pumps only max at 65 psi ( GM specs state 10psi / 1000 RPM
Do what TB states and check ACTUAL pressure with a mech gauge You can take the oil temp sensor out above the filter to install a mech OP gauge

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i tried to find the oil press galley but no luck..


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Last edited by vetteoz; 02-11-2013 at 02:00 AM.
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post #9 of 12 (permalink) Old 02-17-2013, 03:58 PM
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I suspect the sender unit for the gauge ( or the gauge) is faulty.
80 psi is way high for any SBC , no way is a motor with your mileage going to have that pressure.
My new race motors with HP pumps only max at 65 psi ( GM specs state 10psi / 1000 RPM
Do what TB states and check ACTUAL pressure with a mech gauge You can take the oil temp sensor out above the filter to install a mech OP gauge





Stock 350's normally run around 50-55 psi cold and 40-45 psi hot but can drop as low as 25-30 psi at idle.

For a street engine it's never a good idea to run a higher pressure/higher volume oil pump as that'll cause excessive oil to be thrown against the cylinder walls then the oil rings can't control it.
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post #10 of 12 (permalink) Old 02-18-2013, 12:44 PM
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so, did you check the pressure with a mechanical gauge? does it still drop way off?
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