Chevrolet Nova Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
I own a 72 nova with a basic 350 the oil light started flickering on and off during start off in first. I changed the oil yesterday the car has no oil leaks. The oil pressure stay in the 40 to 55 range at idle and while driving. If I push the clutch in and rev the car the oil light does not flash but when the car has forward momentum it will flash on take off. I figure it is a bad censor where do I look to replace it.. Or do I have a bigger problem?
 

·
Registered
Joined
·
5,249 Posts
Assuming that your oil pressure gauge is good, you should look behind the intake manifold where it meets the block on the drivers side. There you should find the oil pressure sending unit. The oil pressure sending unit is easy to change out. I would inspect the single blade plug and wiring going to the sending unit as it may be the culprit before just replacing the sending unit. IF the wiring harness has not been chopped up the oil pressure sending unit wire should be dark blue in color once cleaned off.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
I looked there is it possible that the person who had the car before ran the oil line to gauge out of the same port because that is where it runs to
 

·
Registered
Joined
·
5,249 Posts
If that is where your mechanical gauge is, there is no sending unit there to tell the oil light when to come on or go off. It is probably being trigged by some wire making contact some where, like the original wire for the sending unit. If so, wrap it up with some tape and see if that solves the issue. If you trust your oil pressure gauge and are sure that you have sufficient oil and there is no strange noises coming from your engine, you are probably just fine. You can also remove the bulb from the oil light and you wont see it come on anymore either.
 

·
Registered
Joined
·
12 Posts
Most cars don't run psi of 40-55 at idle, and it definitely should go up when driving or at higher rpm's. An average stock engine will generally run around 20 psi at idle once warmed up.
My previous 71 had a 350 and it would run around 60-80 driving, but around 20 at idle.
Hell, my monster 555 now will run up to 100 psi when first driving cold, drops to around 65 while driving once warmed up, but will drop to between 25-35 at idle.
 

·
Premium Member
Joined
·
17,540 Posts
You could have a functioning mechanical oil pressure gauge and an oil pressure idiot light sending unit on the same motor.

It just means that it is tapping oil pressure in the block at some other point or it is "T-d" off of the other two points that oil can be measured in the block (newer blocks no longer have a front oil tap so that is one down leaving the only other source to tap the oil galleries down by the oil filter).

I also suspect the former loose oil pressure wire is grounding out which is what it would do if you lost oil pressure. Normally I just unplug the sending unit leaving the wire alone as it doesn't cost money and generally the rubber grommet protects the wire and keeps it from grounding out.

Big Dave
 
1 - 6 of 6 Posts
Top