Oil light comes on

[Reynald]

I have a 2004 Mountain Aire with the 8.1 workhorse with about 134,000 miles.  I use Amsoil 5w30 and recommended oil filter from Amsoil, doing yearly oil change. The problem I encountered was when travelling in very steep mountains road, my oil light will come on, normally at lower speed because of grade, I have to release the throttle for it to go out, which slows me down even more. 
Would the oil pump be causing this? What about the oil filter?
Any suggestions before I have to go to the dealer?

 

[rayin]

What oil grade is recommended in your owners manual? Harder working engines usually require a heavier grade of oil. Then again, it might be a faulty oil pressure sender.

 

[Reynald]

Hi and thank you for your help. I used 5w30 as recommended and I will try a new oil pressure sending unit just in case. I will also try some Amsoil 10w30 next month and see what happens.

[wildebill308]

10 hours ago, Reynald said:

I have a 2004 Mountain Aire with the 8.1 workhorse with about 134,000 miles.  I use Amsoil 5w30 and recommended oil filter from Amsoil, doing yearly oil change. The problem I encountered was when travelling in very steep mountains road, my oil light will come on, normally at lower speed because of grade, I have to release the throttle for it to go out, which slows me down even more. 
Would the oil pump be causing this? What about the oil filter?
Any suggestions before I have to go to the dealer?

 

I would install a T at the oil pressure sender and see what it realey is doing. I would also manually downshift on the hills to keep engine rpm up.  The statement "I have to release the throttle for it to go out, which slows me down even more." Makes me think it is the sending unit. Because lifting on the throttle for it to go out would slow the engine and lower oil preshure more.

Let us know what you find.

Bill