oil filter

[DIESEL5]

my 93' is driving my nuts. I did a head job about a month ago and after working some bugs out the truck has been running great until the other day when i started losing oil pressure when at operating temp. I shut the truck off and restarted it cold and had forty pounds of pressure and as it heats up the oil pressure starts dropping so fearing the worst i pulled oil filter off and cut it open to look at the filter material itself i found some metal flakes in it but dont know if its a lot or normal. The idle straightened out with some fresh fuel but as the engine heats up (which only ten minutes to get to 210) kind of fast i think but i could be wrong. I am thinking either i have a spun bearing or an oil pump going bad, the truck has 165 thousand on it and the bottom end. How common is it for an oil pump to go bad on the 6.5. Also when i shut the truck off and restart it while its hot its hard starting. Before i pull the engine I just wanna be relatively sure that i am having a bearing problem. I think i can change the oil pump with the engine still in the truck,(time is of the essence here the snow is on its way)

[JohnC]

If you can drop the oil pan you can eyeball the bearings.

[DaveNY]

Just a Thought, Maybe OP okay and faulty OPS causing low reading and No Lift Pump?
Try Mechanical gauge?
Dave

[DIESEL5]

I Am going to put a mechanical op gauge on it today and do a compression check but after thinking a little more on this issue i cant help but wonder that if when the alt went bad if it spiked maybe and surged the entire electrical system and maybe some how the engine is either running constantly advanced or retarded because that is almost what it seems like and could possibly explain why the temp sending unit went bad at the same time the alt did. I dont know just a thought, I hope to get to the bottom of this gremlin today. thanks for the input and i ll let ya know what i come up with.

[DaveNY]

Bad Grounds make all things goofy!!!

[rhsub]

Minimum oil pressure hot is 6 psi at idle and 30-43 psi at 2000 rpm (GM specs)
Also check + wires from alternator to battery, battery is stablizer in electrical system, alternator can not spike system if all battery + & - circuits are good, if batterys disconnect momentairly alt can make 40 V real quick:eek:
Good luck
Ron

[tommac95]

My recollection is that a (smallish) number of forum members noted a (sudden significant falloff) change in oil pressure which correlated with a discovery on subsequent teardown -- a pressure regulating spring within the oil pump had broken.

So the mechanical gage check may be worthwhile . On rare occassions , a 'bad' oil filter can cause anonomous results , generally immediately after a filter renewal {requiring another new filter to rectify}.

[DIESEL5]

sorry it took so long to get back but i finally put the manual gage on ran the beast for an hour and at 210 degrees the lowest the mechanical oil gage went was 10 psi at idle and at 2000 rpm the pressure stayed at 28 to 30psi that was on a fresh oil change and filter I put a new oil pressure sending unit after the gauge check and ran it for another hour and when hot the check gauges light comes on at idle but goes off when ya give a little pedal and the dash oil gauge goes up I am gonna pull the valve covers off and check all the pushrods for any bent ones and check nylon ratainers if all checks out ok then on to a new oil pump and if that doesn t fix the gremlin then i guess it on to the inevitable complete teardown which i am dreading no time for that right now and getting sick of throwing money at this thing I guess i am fortunate though that i am capable of doing it all myself with some muscle from friends and twelve pack!!!!!!!!!