High oil pressure

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So I recently change my oil over the weekend I have a 440rb engine and usually when I drive the car it stays between 55 and 60 psi like steady but after changing the oil the oil pressure fluctuates when I’m driving it stays at a consistent 60 psi but when I come to a stop at like a light it will fluctuate between 60 and 90 and then sometimes it goes to 120 but as soon I drive again it goes right back to 60 and it’s just recently started doing this I haven’t changed anything yet but I was going to check the sending unit to see if they got dirty or if it needs to be clean or maybe the oil pump which is been on there since I broke in the car like three years ago maybe that went out and I need to change the oil pump when I drop the oil pan there were no bits and pieces in there I had cleaned it out so nothing stuck I change the oil filter and applied oil around the ring and I filled it up halfway before putting it on so I’m kind of running out of ideas on what could’ve caused this to happen
 

thethee

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I'm no expert but I would first verify that the pressure readings are accurate. Do you have mechanical or electrical gauge?
 

Davea Lux

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So need to replace the oil pump?

Usually if the pressure relief valve is bad, the oil pressure will be high all the time, high enough to rupture the oil filter. What type of filter are you using and what weight of oil? Since the problem started with the oil change, you could have a defective filter. I would try changing the filter once you have determined that the gauge readings are accurate.

Dave
 
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Usually if the pressure relief valve is bad, the oil pressure will be high all the time, high enough to rupture the oil filter. What type of filter are you using and what weight of oil? Since the problem started with the oil change, you could have a defective filter. I would try changing the filter once you have determined that the gauge readings are accurate.

Dave
Im using a wix filter and I switch from 10w30 to 5w30
 

Davea Lux

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Im using a wix filter and I switch from 10w30 to 5w30

Wix makes a quality filter, so I doubt that is the problem. Get another gauge and check the pressure readings to verify that they are accurate. If anything, the switch from 10w/30 to 5w/30 would probably drop the oil pressure a little, not increase it. 5w/30 is a bit on the light side for a vintage Mopar. They generally ran 10w/40 or straight 30w when these cars were new. Your engine runs a flat tappet cam, so be sure the oil has plenty of zinc additives. I run Valvoline all fleet 15w/40 for that reason in all of my Mopars. Chevron RPM Delo 400 or Shell Rotella also make quality high zinc oils in the same viscosity range. Some of the modern synthetic oils use additives other than zine to accomplish proper lubrication of flat tappet cams. Valvoline ZR1 racing oils in either full synthetic or conventional oils also provide excellent wear protection. It is usually not a good idea to run a full synthetic oil in a a well used engine because the synthetics can break loose a bunch of crud and cause problems.

Dave
 
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Wix makes a quality filter, so I doubt that is the problem. Get another gauge and check the pressure readings to verify that they are accurate. If anything, the switch from 10w/30 to 5w/30 would probably drop the oil pressure a little, not increase it. 5w/30 is a bit on the light side for a vintage Mopar. They generally ran 10w/40 or straight 30w when these cars were new. Your engine runs a flat tappet cam, so be sure the oil has plenty of zinc additives. I run Valvoline all fleet 15w/40 for that reason in all of my Mopars. Chevron RPM Delo 400 or Shell Rotella also make quality high zinc oils in the same viscosity range. Some of the modern synthetic oils use additives other than zine to accomplish proper lubrication of flat tappet cams. Valvoline ZR1 racing oils in either full synthetic or conventional oils also provide excellent wear protection. It is usually not a good idea to run a full synthetic oil in a a well used engine because the synthetics can break loose a bunch of crud and cause problems.

Dave
I’ve used royal purple since I broke the engine in I just switched from the 10w30 to 5w30
 
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