Stupid Question: Low Oil Light

[idro]

Ok, i have been trying to find a wiring schematic to answer my question but veryusefull doesnt really have one to tell me what i need.

I have an aftermarket oil pressure gauge in the car and it read like it was supposed to all night last night. 20-25 psi~ idle and 37.5 psi WOT~ that is what it has always read so im taking that to be normal. Fyi: the engine is a new 306 built by me. Well i was driving home last night, and the low oil light came on. Think its just another one of fords dummy lights that i need to pull the bulb on, or should i go digging around looking for a problem. I got the car home last night no problems, but it was dark and i didnt get to check the dipstick, but with a new engine and no oil on the ground im sure i have what im supposed to have in there.

Thoughts?

:dontknow:

 

[CC'S95GT]

There is a sensor on the l/h side of the oil pan. maybe the wire touched the header and melted or shorted out.
Assuming you actually have oil in the pan. lol

 

[idro]

There is a sensor on the l/h side of the oil pan. maybe the wire touched the header and melted or shorted out.
Assuming you actually have oil in the pan. lol

LOL hopefully. But you're on to something, i didnt think about that. I was parked on an incline last night. I feel damned stupid. Ill go back under my rock.

 

[rz5.0]

mine came on one day. so i just put a quart of oil. when i started my car light was off. after about 30min of driving my car started smoking. check the oil and i had too much in it. about a month ago it came back on i checked my oil it was ok turn the car off a let it sit for a min started again the light was off.

 

[modo]

that light is a ground switch. if its on i would say it is low...

what were the bearing clearances? 37.5 @ WOT is low

 

[idro]

that light is a ground switch. if its on i would say it is low...

what were the bearing clearances? 37.5 @ WOT is low

What should it be at WOT? Its always been that... since day 1...

 

[modo]

that light is a ground switch. if its on i would say it is low...

what were the bearing clearances? 37.5 @ WOT is low

What should it be at WOT? Its always been that... since day 1...

depends on the clearances and what the clearances are dictate what oil you should be running.

with that being said, 25-30 @ idle and a addtional 10 psi per 1000 rpm is normal. i would want a minimum of 60 psi at wot on my motor

.02

 

[idro]

When you talk about bearing clearances, what are you talking about? Im running 10-30 with my car... :dontknow:

 

[idro]

Eh, after some digging i figured why mine is probably lower than what you would expect... Since i had a cobra i had to afro-engineer the sender to work with my setup. I had to buy a couple of copper fittings to adapt the sender to my car, so yea well. And i didnt opt for a mechanical gauge... :crybaby2:

 

[NXcoupe]

Uhm one, the afro comment is kind of lame. Two, those fittings are not going to really affect the reading since pressure is equal throughout any fluid system. Yes, that is not good oil pressure, and you said you assembled your engine but you don't know what oil clearances are? Did you check them? That means you take plastigauge and see how much clearance is between the crank and the bearings, both main and rod bearings. This space between these two parts is filled with oil when the engine is running and is called oil clearance. Hope that clears it up for you, and yeah, your low oil light is probably the wire you had to cut when you pulled the engine out just grounding out on the frame somewhere.

 

[idro]

The engine has been in the car for about a year and a half now. So i don't think it was just shear coincidence that the low oil light came on. It was probably because i *WAS* in fact parked on the side of a hill that night and when i made the post i did not put 1+1 together to make 2 with the low oil sensor being on the l/h side. As far as oil clearances, ive never heard of that and thanks. But from what i've read it isn't anything that i can clear up by tearing down the engine again, should i be using a lighter weight oil, or what? As far as cutting wires to pull the engine, i did not have to cut any...

 

[NXcoupe]

Ok, then you pulled the low oil wire out of the side of the pan successfully? then you were very fortunate. That happens very rarely. It still could have melted onto one of the header tubes, but if you parked on a hill and it came on, I would still check the oil.
I would run a little thicker oil with that low oil pressure, but before I did that, I would use a different gauge, pick up a cheapy at AZ and just see what it reads. Or borrow a buds gauge and try it. Then if it is still low, run one step thicker oil. Is it higher when it is cold than when it warms up?

 

[idro]

Ok, then you pulled the low oil wire out of the side of the pan successfully? then you were very fortunate. That happens very rarely. It still could have melted onto one of the header tubes, but if you parked on a hill and it came on, I would still check the oil.
I would run a little thicker oil with that low oil pressure, but before I did that, I would use a different gauge, pick up a cheapy at AZ and just see what it reads. Or borrow a buds gauge and try it. Then if it is still low, run one step thicker oil. Is it higher when it is cold than when it warms up?

No, on my car it has a sensor that screws into the side of the oil pan. Ill snap a picture if you want.

If i crank it up from cold start it is approximately in the 50psi range. Probably 50-60. Then once it gets warmed up and im cruising down the interstate its around 20-25. Then when i am WOT it is around 35-40. My gauge is an autometer phantom 2 so just judging where the arrow is are my estimations...

 

[orodi]

I would say run thicker oil. But I do have one other thought, Are you running a high volume pump and a stock pan? This too can suck the pan almost dry in high RPM. If so you have one of two options either change the pump or change the pan.

 

[NXcoupe]

Ok, then you pulled the low oil wire out of the side of the pan successfully? then you were very fortunate. That happens very rarely. It still could have melted onto one of the header tubes, but if you parked on a hill and it came on, I would still check the oil.
I would run a little thicker oil with that low oil pressure, but before I did that, I would use a different gauge, pick up a cheapy at AZ and just see what it reads. Or borrow a buds gauge and try it. Then if it is still low, run one step thicker oil. Is it higher when it is cold than when it warms up?

No, on my car it has a sensor that screws into the side of the oil pan. Ill snap a picture if you want.

If i crank it up from cold start it is approximately in the 50psi range. Probably 50-60. Then once it gets warmed up and im cruising down the interstate its around 20-25. Then when i am WOT it is around 35-40. My gauge is an autometer phantom 2 so just judging where the arrow is are my estimations...

Well, that's what I'm talking about, most people just try to unplug it which is how it is designed to be disconnected, but unscrewing it is a way too.
Your oil pressure indicates to me that you have either too much rod bearing clearance or side clearance on the rods. Or it could be the cam bearings are worn out. I am assuming tho that you had new ones put into the block when you had the block work done? So it is probably the bearing clearance somewhere as it gets worse when it warms up. MOst cars drop a little, a car with too much clearance drops a lot because everything swells up giving more clearance. Just drive it and enjoy it with some thicker oil.