1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Whacky oil pressure....

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Old Mar 13, 2005 | 05:06 PM
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Whacky oil pressure....

I went about a week without driving my 84 SE then next time I did the oil pressure guage was acting funny... Now I need you guys help trying to find out if it's a serious engine problem, or just a messed up guage.

Perviously at idle my guage (stock guage) would say anywhere from, probably 40-60 PSI.
Then it was at maybe 5-10 PSI, sometimes dropping to zero. But the performance of the car never changed, I could tell no difference from when the guage used to say 50PSI and when it said 3 PSI now.
But, sometimes when I really got into it (6000 rpm or so) the gauge would shoot up to 40-60 again, then drop right back down to 3 or 4 PSI.
So is it a bad oil pressure sender or am I in for some expensive repairs? Any guesses?
Also when searching, I read that gassy oil could maybe do it, and my oil almost always smells somewhat like gas, but I changed it today and that didn't seem to help.

Last edited by Hadoken; Mar 13, 2005 at 05:13 PM.
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Old Mar 13, 2005 | 06:38 PM
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A poor ground somewhere in the system can make your guages read irratically. I once replaced a lot of coolant system parts trying to make my car run cooler when the only problem was a poor ground from when I relocated my battery. I installed a heavier ground cable and a ground cable to the engine and the car suddenly started running cooler!!! It also affected my pressure gauge so I would consider this a possibility. When you floor it the pressure gauge may spike because your battery shifts temporarily giving a good ground, just a thought.
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Old Mar 13, 2005 | 07:41 PM
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From: St Joe MO
Check the wire connection at the sending unit. Clean it with brake cleaner and make sure the is no corrosion. There is also a little black box that bolts to the engine above the sender (top of the block). Make sure it is connected and has a good ground to the block.
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Old Mar 13, 2005 | 07:47 PM
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With my little previous knowledge a piston engine will knock when it has very low oil pressure, but what sign is there of a rotary engine when the oil pressure is low?
Since I've noticed no difference in performance, I'm thinking it's something to do with the gauge/sensor, but what would I notice different if the oil pressure was low or zero?
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Old Mar 13, 2005 | 08:02 PM
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From: St Joe MO
Possibly overheating, more likely a seized engine, eventually.
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Old Mar 13, 2005 | 09:42 PM
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funny, mine is doing the EXACT same thing and i was getting ready to make a post. i think mine is due to low oil pressure though. when the engine is at idle, it reads ~10psi, but if i go to 1500rpms, it will go to ~30psi. and about 2k it will be ~60ish. it only drops that low at idle when warm. anything i can do to fix this? oil pump problem? anything that can be fixed easily? im assuming not
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Old Mar 13, 2005 | 10:19 PM
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Originally Posted by onepointone
funny, mine is doing the EXACT same thing and i was getting ready to make a post. i think mine is due to low oil pressure though. when the engine is at idle, it reads ~10psi, but if i go to 1500rpms, it will go to ~30psi. and about 2k it will be ~60ish. it only drops that low at idle when warm. anything i can do to fix this? oil pump problem? anything that can be fixed easily? im assuming not
Those pressure readings are close to normal. Per Haynes, 13-38 psi at idle, 64-78 psi at 3000 rpm of engine.
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Old Mar 14, 2005 | 07:21 AM
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When are you guys gonna learn NOT TO TRUST AN OLD GAUGE. You guys need to install a MECHANICAL GAUGE for a much more accurate reading.
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Old Mar 14, 2005 | 08:30 AM
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Talking Whacky/wacky

Originally Posted by wackyracer
When are you guys gonna learn NOT TO TRUST AN OLD GAUGE. You guys need to install a MECHANICAL GAUGE for a much more accurate reading.
Your just upset because they spelled your name wrong when they started the thread,lol . rx7doctor
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Old Mar 14, 2005 | 09:27 AM
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From: Socal
Originally Posted by rx7doctor
Your just upset because they spelled your name wrong when they started the thread,lol . rx7doctor

lol
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Old Mar 14, 2005 | 11:07 AM
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From: Hickory,North Carolina
I guess it is "wacky"...I've always said it WHACKY like, WHACK with a Y on the end.
My deepest apologies : P
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