Safe, upper oil pressure limit?

[Oz]

I know oil pressure will fluctuate from idle through acceleration and deceleration and cruising.  Here's the situation:

Normally, the pressure gauge reads 35 - 40 psi at idle.  Acceleration up to 55 psi.  Cruising... 50 psi.  Like clockwork.  This is "normal" for the engine (Chevy 5.3).

I changed the oil and filter.  Got a good deal at AutoZone on 5.28 quart, oil change size Mobile 5000 mile oil with STP filter.  Twenty bucks!  I got the correct filter.

After changing the oil, my oil pressure is 40 psi or a little above at warm idle. During acceleration, it goes up to 65 psi.  Cruising at 55 - 60mph, it's at 60 psi.  The gauge max is 80 psi.

I thought I might have overfilled the oil even though I checked it a few times after changing it.  I checked it again after a 14 mile, mixed traffic-open highway drive.  The oil level is right on the money.

Is this safe to drive at 10 psi higher pressure or will I blow something? 
What would cause this change in psi?  the oil filter is the same size, but a different brand than before.  The oil is different as well.  Would that have anything to do with it?  I've never had this happen before with any vehicle.


i??

[tgerlach]

I have found this before.  The filter is probably causing this.  Used to filnd this when customers changed from a orange brand of filter, to a pure one.   not giving up brand names.  Don't problems down the road.

[LJ-TJ]

Not sure if this helps? On page 9-59 of the Dodge Motor Home Chassis Service Manual for the M-300,M-375,RM-300,RM-350 and RM-400 states. Minimum Oil Pressure at idle   8 psi.
                      Pressure at 2000 Engine RPM 30-80

I just installed a Autometer oil pressure gauge that I am doing trial runs with now and it seems to run at a steady 60 psi. I'll be taking the rig out for 200 mile run this weekend so if your interested I'll let you know what happens when we get back. Hm?

[Oz]

Good info there, TJ.  The Chevy engine runs at a higher psi on the low end (idle).  I was thinking about the oil filter as being the cause as well, tgerlach, since the last oil change was at a shop and they used a generic, plain, white, NAPA filter and I put in an STP filter.  Thank you for confirming that.

The gauge goes up to 80 and the pressure will fluctuate from a consistent 45psi at idle (normal = 30 - 40) up to 70 psi during acceleration, and 60 psi at cruise speed (normal = 55).

Is this something to be concerned about?

[legomybago]

I've had the same happen to me years ago on an old Ford pickup, but it was already running a little low on pressure...so I was happy with the filter I put on that made higher oil pressure for what ever reason i??  Im not sure I would worry about your pressures now, but you could go grab a differant filter and throw it on...for peace of mind

[Lefty]

I only use Napa Gold filters on my vehicles. I've seen cut-away versions of STP, Fram, and othe brands, as well as the Napa Gold versions... The Napa versions are much better constructed internally.

Heavier filter paper, more pleats to expose more surface area, better materials used for the internal baffles and anti-drainback valves, and also the filter canister itself is heavier steel to prevent warpage (which can cause leaks) and resist rupture.

Never had a problem yet.

[cncsparky]

I wouldn't be concerned at all.  Stock engines have pressure relieving oil bypasses if it gets higher than the OEM designed. 

STP filters made by Champion Labs, excellent filters.  NAPA Golds made by Wix, also excellent IMO (What I run).

[DaveVA78Chieftain]

The basics: http://www.freeasestudyguides.com/oil-pressure-relief-valve-function.html

New filter may have a higher flow rate design than the original.

Dave