Topic: oil pressure wacky
in Forum: C3 Engines
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
Former Member
Send PM
Phoenix, AZ - USA
Joined: 6/12/2011
Posts: 139
Vette(s): 1982 corvette crossfire production numer C5101985. Color is silver and claret. All original numbers match. slight mods to crossfire for better efficiancy and power balanced and added fuel pressure assembly between throttle bodies,
so I just put a new radiator in the car. I cleaned the engine bay while it was down. I didnt use a high pressure spray and was careful around all the connections.
|UPDATED|5/14/2014 8:14:54 PM (AZT)|/UPDATED|
anyway my oil pressure guage is bouncing, from 40 to 80 back to 45 holds steady in drive while driving at 40, stop light it jumps to 80 then as i pull forward it goes back to 40.
got it home and shut it off, pressure jumped to 80 then slowly moved down to zero.
Is my sending unit fried? or pressure unit fried?
i checked the connections and they look tight no wiggle, no grounding on anything.....
any ideas
I changed the oil and filter 2 weeks ago so i know its got good oil in it.
|UPDATED|5/14/2014 8:14:54 PM (AZT)|/UPDATED|
SPONSOR AD:: (Our Sponsors help support C3VR)
Lifetime MemberLemon Grove, CA - USA
Joined: 10/17/2007
Posts: 2041
Vette(s): 1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.
Just some info on the gauges. I do not know if the oil pressure is like this but My gas gauge would bounce around like that. Know one could come up with a fix for it. I happened to have a new gauge I purchased just because I got a good deal on it. It was the gauge. It seems that it has a dampening coil in it and that all of a sudden stopped working. Without the dampening coil the gauge will bounce. Now if it is steady at a pressure and not bouncing around it then this is not your issue.
I just though I would give you something to think about.
The gauges in these cars are sh... Uh, I mean garbage. Saying that,
however, I don't believe in coincidences. If you washed the engine down
and then the gauge went whacko, the sensor probably went or (less likely)
water found its way into and is messing with the harness. Unplug the
sensor and dry out the plug w/wd-40 or contact cleaner.
If that doesn't work, I'd change the sensor before I took that dashboard apart. It just unplugs and unscrews. (It's on the back of the engine block, drivers side.) Pretty easy to do. That dashboard, on the other hand, is best left untouched...
If I remember right, the FI cars have a funny oil switch that shut off the fuel pump if oil pressure is lost. Joel might better answer that. But if the sending unit fails, I believe your fuel pump won't deliver fuel and the engine will not run, so if it's failing, I'd fix it quickly.
If that doesn't work, I'd change the sensor before I took that dashboard apart. It just unplugs and unscrews. (It's on the back of the engine block, drivers side.) Pretty easy to do. That dashboard, on the other hand, is best left untouched...
If I remember right, the FI cars have a funny oil switch that shut off the fuel pump if oil pressure is lost. Joel might better answer that. But if the sending unit fails, I believe your fuel pump won't deliver fuel and the engine will not run, so if it's failing, I'd fix it quickly.
"Let them that don't want none have memories of not gettin' any."
- Brother Dave Gardner
Former Member
Send PM
Phoenix, AZ - USA
Joined: 6/12/2011
Posts: 139
Vette(s): 1982 corvette crossfire production numer C5101985. Color is silver and claret. All original numbers match. slight mods to crossfire for better efficiancy and power balanced and added fuel pressure assembly between throttle bodies,
dyoes said: The gauges in these cars are sh... Uh, I mean garbage. Saying that,
however, I don't believe in coincidences. If you washed the engine down
and then the gauge went whacko, the sensor probably went or (less likely)
water found its way into and is messing with the harness. Unplug the
sensor and dry out the plug w/wd-40 or contact cleaner.
If that doesn't work, I'd change the sensor before I took that dashboard apart. It just unplugs and unscrews. (It's on the back of the engine block, drivers side.) Pretty easy to do. That dashboard, on the other hand, is best left untouched...
If I remember right, the FI cars have a funny oil switch that shut off the fuel pump if oil pressure is lost. Joel might better answer that. But if the sending unit fails, I believe your fuel pump won't deliver fuel and the engine will not run, so if it's failing, I'd fix it quickly.
If that doesn't work, I'd change the sensor before I took that dashboard apart. It just unplugs and unscrews. (It's on the back of the engine block, drivers side.) Pretty easy to do. That dashboard, on the other hand, is best left untouched...
If I remember right, the FI cars have a funny oil switch that shut off the fuel pump if oil pressure is lost. Joel might better answer that. But if the sending unit fails, I believe your fuel pump won't deliver fuel and the engine will not run, so if it's failing, I'd fix it quickly.
So I took it off, cleaned the sensor the plug looks pretty dry, I lightly sanded the conectors to get the old build up off, put it back in. at an idle in park, pressure reads normal, in drive with brake on pressure is normal. I will post tomorrow if that fixed it.
thanks for the imput, for some dumb reason i was looking at the sensors on both sides of the motor and not the oil pressure sensor on the rear of the block 
My car doesnt have a clock like most of them came out with I have a oil temp gauge instead so I am assuming one of those on each side goes to it.
I do not know if the oil Temp is factory or what i do know ive never seen it in place of the clock, but i hear lots of problems with the clocks so I am glad i dont have one
in Forum: C3 Engines
SPONSOR AD: (Our Sponsors help support C3VR)