Oil Pressure
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New User
Joined: Jan 2001
Posts: 16
Likes: 0
From: Simi Valley USA
Oil Pressure
What would cause oil pressure fluctuation at Idle?
I bought this truck a couple years back and have been slowly working on getting it drivable, the previous owner says the motor was a newly rebiuld. One thing I did find is that when I went to put a new oil pan on it the bolts to the oil pump were loose. I swapped out the oil pump for a high volume pump and new gasket and tightened it all back up. One thing is the truck hasn't been run for about a year till last weekend when I fired it up. I'm concerned about this motor because of all the things I have found wrong since I got this truck missing power steering pump, missing kickdown rod, mickey mouse throttle rod missing bolts.
I learned my leason to look things over more carefully!
Sorry for rambling on.
Thanks,
John
I bought this truck a couple years back and have been slowly working on getting it drivable, the previous owner says the motor was a newly rebiuld. One thing I did find is that when I went to put a new oil pan on it the bolts to the oil pump were loose. I swapped out the oil pump for a high volume pump and new gasket and tightened it all back up. One thing is the truck hasn't been run for about a year till last weekend when I fired it up. I'm concerned about this motor because of all the things I have found wrong since I got this truck missing power steering pump, missing kickdown rod, mickey mouse throttle rod missing bolts.
I learned my leason to look things over more carefully!
Sorry for rambling on.
Thanks,
John
Elder User
Joined: Feb 2004
Posts: 835
Likes: 0
From: Fort Rucker, AL
Mine does the same thing. I was reading through the forum to see what has been said about it. I'm running about 20 psi at an idle and my oil light comes on. At rpm the light goes out. Plus my lifters rattle. Here's the clincher, I just rebuilit the motor and everything in it is brand new. Help?
Post Fiend
Joined: Feb 2001
Posts: 6,624
Likes: 8
From: Missouri
I'll tell you what mine runs with 5W30 synthetic (used in winter).
At idle it runs 15PSI when hot. At 2,000rpm its up to 50psi. At 5,500 rpm it is a tad over 80psi.
My lifters don't rattle and I don't think I am hurting anything. When I run 15W50 my idle pressure is around 35psi I think but that would require me to remember all the way to before my 1 year tour in Korea.
At idle it runs 15PSI when hot. At 2,000rpm its up to 50psi. At 5,500 rpm it is a tad over 80psi.
My lifters don't rattle and I don't think I am hurting anything. When I run 15W50 my idle pressure is around 35psi I think but that would require me to remember all the way to before my 1 year tour in Korea.
Senior User
Joined: Jun 2002
Posts: 119
Likes: 0
From: simpsonville USA
20 at idle seems fine. Rule of thumb is 10 for every 1000 RPM's. Mine running hot at 800 RPM is about 20. Rpm's up and it runs consistently at about 60 when hot. I'm in the 80s when cold. This is a new rebuild with 10W40. The pressure will fluctuate with engine RPMs of course but if there is no stumble then there could be an issue. I guess depends on how much of a fluctuation. I am certainly not a guru like some on this forum but I would tend to think if your lifters are clattering, either your valves are adjusted incorrectly or there may be a problem with the cam. I would identify which lifters are clattering, and check your clearances.
Ken
68 F100 390
74 Bronco 351W
Ken
68 F100 390
74 Bronco 351W
