Oil Pressure Problem!!!

[big_blue_chevy2006]

well as of right now i have 10w30 valv. maxlife oil in my truck, its due for a change about now, i have a high volume oil pump installed with a mild street cam in it. at idle my oil pressure used to be 30 and when goin down the high way it was about 50 or so. when the oil is still cool its fine but once it warms up the pressure drops to bout 30 on the high way and just under 15 at idle, the other night it was at 0 and the check guage light came on, but i found i was a qaurt low some how?? i ahve no leaks and it dont burn any oil out the exhaust? so i added a quart and a half and the pressure is still jus under 15 at idle. so what im asking is whats causing this? is it because im due for a oil change? also how about a synthetic oil, i plan to change over to a synthetic oil but i heard that there oil pressure problems with synthetic? thanks guys

[broughy84]

15 at idle is fine. You have a high flow oil pump, but is it high pressure. Look at it this way, 10psi oil pressure per 1000 rpm. So.... you idle at around 700-800 rpm and you have 15 psi you are fine. As long as the pressure doesn't bottom out you are fine.

[big_blue_chevy2006]

well it was spose tob e just a high volume but it also raised the pressure, i just wasnt sure tho bc it was higher at idle than what it is now

[mbumgua]

Your pressure bypass on the new pump is probably set too low.

[big_blue_chevy2006]

how would it change? it was fine for a month the pressure was around 30 at idle.

[mbumgua]

All oil pumps can be high pressure if you put in a stronger spring in the bypass valve. High volume pumps have longer gears for more volume. If your spring has weakened it would lower your idle pressure. I would try a 10w-40 or 20w-50 and see if it changes. As your oil ages it gets thinner and could account for the drop in pressure at idle. What brand of oil pump did you use?

[big_blue_chevy2006]

i used a melling high volume oil pump, i havnt ever touched the spring in it, i use 10w30 oil, the pumps about a month old now i dont see how it would have weakened so easily.

[mbumgua]

Change the oil and use 10w-40, see if that helps-Remember not much is made as good as used to be.