please help me before this car kills me. sum everything up aftermarket gauge with nylon tube going to gauge oil is full and changed it 2 weeks ago hd40w castrol replaced brass fittings and they arent leaking. oil light came on after replacing fittings. alternator and volt reg was changed yesterday. oil light comes on when key is on and stay on while motor runs. please help me i have searched everywhere. no lifter tapping or knocking noise but do smell oil in exhaust
update after calling a buddy over to look at it. the light went off while idling came on then went off. thank you for answering so quickly i am not having the most luck last month with the maverick. is 20psi good at idle for oil i am running hd40w
oil pressure The sending unit for the idiot light is pre set at I believe 35 psi. If you did not have a red light when you used say 10w40 and you have one with straight 40, I would switch back to multi viscosity oil. You should have 10 lbs. of oil pressure for every 1000 rpm. So if your engine goes to 5000 rpm, you should have 50 psi. I hope your bearings or oil pump are o.k. Dave.
i was told to run straight weight by many performance shops. thats why i made the switch. should i run 20w50 or 10w40 if i switch? live in florida they better be okay i paid for a new 347 traded two blocks and had most of the bolt ons from my old 302 to swap over cost me 3000 so i hope i didnt get screwed over if i did karma will be a bitch for him.
I was taught that the first number of multi visc. oil say for 20w50 means that at room temperature (70 degrees) the oil will flow as a 20 weight but when it is heated it becomes thicker 50 weight. Your straight 40 should be good. Try changing the idiot sending unit before condemning the engine. I hope that helps. Dave.
The "W" stands for "Winter" I found this: The SAE classifications characterises the viscosity at low and high temperature of the lubricant. The grade is given by two numbers separated by the letter W (meaning winter). The first number, followed by W represents the low temperature viscosity, 5W, 10W, 15W... the lower this number, the more fluid at low temperature the oils, the easier the engine starts. The second number gives the high temperature viscosity: 30, 40, 50. The higher this number, the more viscous the oil when hot.
run 10w 40 or 10 w 30 in it 20 psi at idle on a old motor is ok not great if it does'nt smoke or knock or rattle don't worry about it
no need to run 20 50 in a street car 40 or 10 40 is great. that oil pressure is ok what pressure is it at 2500 rpm at normal temp?
the oil light comes on when the oil pressure is below 7psi. That is still the same to this day. If you have a Ford made after 1988 (say a 89 Mustang) and you have a factory gauge it is also a idiot light. Ford used the same style setup as the light with a 150ohm resister in line to make the gauge stay in the middle. so if you have a actual mechanical gauge and it says 20psi then you are fine and there is a wiring issue with the light.
I never worry all that much about oil pressure at idle. If you have 10-20 psi at idle your good. Most engines will pick up a significant amount of oil pressure above 1500 RPM. 20w50 oil is a pretty heavy oil, mainly intended for racing use. A good 10w30 should work just fine and probably get alittle better MPG aswell. Hell we run a 10,000 rpm motor @80 with 0w20 - 0w5 in it. It all depends on the clearances. If your motor has over 10,000 miles on it I'd serioulsy consider going to synthetic oil. Synthetics handle the temp changes much better. They don't thicken up as much in the cold and don't think out as much in the heat. And for those that don't already know there is nothing Synthetic about a synthetic oil. It comes from the ground just like every other oil. Synthetic oils have been altered so all the molecules are the same. Helps lower the oils resistance to flow and the temp characteristics i mentioned earlier. Well I've babbled enough.
