oil light issues can you help?

[a68cudas]

Well my oil light will start to come in the m1009. Once blazer is warmed up and you drive its fine the light is off but when you come to a stop and blazer ideling it will start to come on once you give it gas to go it goes off? I changed oil and filter few days ago and checked oil level its where it should be. sometimes the light will flicker and some times doesnt and stays solid red when at idle? what should i check or what could my problem be?

 

[doghead]

I would connect a mechanical oil pressure gauge and see if you have good oil pressure. And go from there.

Is your idle too low? Did this just start after an oil change? What did you use for oil and filter? Does it do this at idle, when cold and hot?

 

[a68cudas]

I would connect a mechanical oil pressure gauge and see if you have good oil pressure. And go from there.

Is your idle too low? Did this just start after an oil change? What did you use for oil and filter? Does it do this at idle, when cold and hot?

i used valvoline 15x40 for diesels and a fram ph5 filter. yes it started b 4 oil change it was the first thing on my checklist to do once i got it home from recovery. i think its only doing it once its hot ill check next time i start it cold. i have a mechanical guage from another cluster i use for spare parts from for a 77 chevy c10 can i use it?

 

[dstang97]

Either bad switch or low oil pressure. I would def hook up a mechanical guage to it.

 

[a68cudas]

when mechanical is hooked up what is a good pressure that it should be during idle?

 

[a68cudas]

Can i use the mechanical oil guage from 77 checvy c10 the cluster is same? How do i go about hooking up either this guage or another mechanical oil guage? Thanks

 

[319]

I'd suggest buying or renting a mechanical oil pressure test gauge. It will have several adapters. You can remove the oil pressure sending unit and conect it there. Read the procedures in the Technical Manual(s). It will specify the correct pressures.

 

[ida34]

It would be cheaper just to buy a cheap oil pressure gauge from the local auto parts place. At idle you should have around 15 lbs or above. Most factory gauges were electrical not mechanical. The mechanical gauge with have a tube that attaches to the spot where the oil pressure sensor was. Remove the old sensor then put in the mechanical gauge and run it. The oil directly travels up the tube to give the pressure reading. If you want to get fancy get some small pipe fittings and make a T so you can keep the oil pressure sensor connected. Then when the light comes on you can see what the pressure actually is. If the pressure is good on the mechanical gauge then replace the oil pressure sending unit. If the pressure actually is low then you have bigger problems. It is also a good idea to leave the mechanical gauges connected and just mount them up inside as they are cheap insurance.

 

[ida34]

Based on what you are asking you seem to be over your head on this one. Do you have someone else that can help you through the process? For your info as I think I was not clear enough in my other post, you have three types of oil pressure warning devices. The are as follows:

Idiot light A pressure sensor switch is attached to the block at an opening that connects to the oil passages. When enough pressure is present the switch is open. When the pressure gets low the switch allows contact and turns on the light in the dash.

Electrical gauge A pressure sensor is attached in the same place as described above. This has an internal sensor that reacts to the different pressures by varying it's resistance. The different resistance values cause more or less current to flow to the gauge and this causes the needle on the gauge to change according to what pressure the sensor sees.

Mechanical gauge A tube is connected to the same place described above. The tube connects the gauge directly to the oil passage by the tube. The gauge is directly effected by the pressure causing the needle to overcome a spring holding it back. This then shows the pressure directly and more accurately than the other methods.

 

[4bogginchevys]

i'll bet it's just the sending unit, a few bucks....fixed

 

[ida34]

A sending unit or major engine problems. It can only be one of the two.

 

[a68cudas]

Based on what you are asking you seem to be over your head on this one. Do you have someone else that can help you through the process? For your info as I think I was not clear enough in my other post, you have three types of oil pressure warning devices. The are as follows:

Idiot light A pressure sensor switch is attached to the block at an opening that connects to the oil passages. When enough pressure is present the switch is open. When the pressure gets low the switch allows contact and turns on the light in the dash.

Electrical gauge A pressure sensor is attached in the same place as described above. This has an internal sensor that reacts to the different pressures by varying it's resistance. The different resistance values cause more or less current to flow to the gauge and this causes the needle on the gauge to change according to what pressure the sensor sees.

Mechanical gauge A tube is connected to the same place described above. The tube connects the gauge directly to the oil passage by the tube. The gauge is directly effected by the pressure causing the needle to overcome a spring holding it back. This then shows the pressure directly and more accurately than the other methods.

no not over my head just needed to know whereto hook up line to. ive never hooked one up before. you explained it pretty well and the T is a good idea and ill keep the guage hooked up under dash. Its always best to ask then to suffer consequences for not asking or not hooking something up right.

 

[a68cudas]

Does anyone know the Napa part number for sending unit? Think ill just change sending unit and put new oil pan gasket on and also hook up mech guage and then i can always see what my pressure is.

 

[doghead]

Did you look for the part number in the -20P, yet? I would start with that....

 

[a68cudas]

Did you look for the part number in the -20P, yet? I would start with that....

looked up everything last night got all numbers for parts i need and looked up NAPA parts to see what they would cost and wrote down #s needed. gonna pick up what i need today Thanks

 

[a68cudas]

replaced the sending unit oil pressure switch and lights still coming on. A friend has a oil pressure gauge from work hes gonna hook up today or tomorrow and see what pressure is. was reading also in one of manuals where it said to check idle rpm using ste/ice tester and set rpm to 625 by turning idle screw adjustment on injector pump. I have a question. How can you go about checking and setting rpm to 625 on IP if you dont have the ste/ice tester? How can i go about doing this? Thanks

 

[doghead]

Buy ear! or with an optical tach, or possibly a contat tach. or a fuel line clamp tach, or an alternator tach(like the ste/ice has)

 

[FMJ]

I'm afraid your engine is about to go south, I may be wrong, but I think the idiot light comes on when pressure in less than 5 psi?
You'll have your answer as as soon as you get a mechanical gauge on it. Good luck!

 

[lavarok]

I'm afraid your engine is about to go south, I may be wrong, but I think the idiot light comes on when pressure in less than 5 psi?
You'll have your answer as as soon as you get a mechanical gauge on it. Good luck!

If your mechanical gauge reads the same, drop your oil pan and check the sump and the pump. You might be able to replace the oil pump to resolve the issue.

 

[a68cudas]

well just came in from outside. Freezing out there. Anyways i couldnt get ahold of friend who had the shop gauge so i built a t and hooked up both the sending unit and mechanical gauge. when engine cold start i get 15 lbs then as it warms up it drops to hardly anything. If you give it gas in park it will go back up to about 15 20 lbs. I got the pan gasket set and a new pump. Hopefully this will solve the problem. I had another vehicle few years back that did same thing and dropped pan new pump and was fixed, but im new to diesels and what other problems this could be can you guys share some thoughts on what it could be and if you think its the pump taking a s**t as well? Thanks