Friends 'low' oil psi 340, only about 10,000miles

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By any chance did he put a new MP front cam thrust plate on the motor. My bud did and it has a groove that oils the timing chain that is way to big and he had oil pressure like you stated. Changed it back to the stock one and it was fine. You can plug it with a oil galley plug as well.

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Nope, stock thrust plate with a summit racing timing chain.

Thanks

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I'd say make sure they put in the oil plug in by the dist drive.

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I would try it without the lucas crap in it and report back- I tried it in my work truck and in knocked down the pressure by 10psi - bad enough that the pressure light would come on at a hot idle.

I was P.O.'d because it takes 12qts of 15/40 and a $25 filter- cheaper than 7k for a new motor though.

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First thing I'd do is try another gauge; then cut the oil filter open and inspect the element for bearing material.
Could be bearing clearances too large, oil being aerated, maybe the filter going into bypass. Sounds like the oil has to be cold (thicker) or the pump spun up to maintain oil pressure, which sounds like an internal (pressure) leak. It doesn't sound fatal, but it doesn't sound right, either; mine have always idled hot with at least 30PSI with a stock pump and regardless of mileage.

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thanks for the reply. I think i have another gauge he can toss on there. Whats the best way to cut the filter open? Do we need the whole filter cutter tool, or can we just zip it in half and peek in there? Could it be possible the oil pump is bypassing itself or something wierd?

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Had the same problem years ago with a rebuilt 340. Ended up being that the engine had one factory oversized lifter bore! Check the front of your block to see if it is stamped with (I believe) a diamond. If so, you will need to bush which ever lifter bore(s) back to standard size inorder to use your lifters.

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thanks, there were no symbol stampings on the block when he had it hot tanked before the rebuild.

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I agree with Hemi Rick and Mopar Joe, 10 psi for every thousand min, get the lucas out, try another gauge to be sure, if you are still worried try a oil analysis. btw what oil pump is he using? and why use the diesel oil

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What oil filter are you using?

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hot cruise is about 40 (~3,000rpm) and might get up to 50 if he runs it through the gears.

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First thing I'd do is try another gauge; then cut the oil filter open and inspect the element for bearing material.
Could be bearing clearances too large, oil being aerated, maybe the filter going into bypass. Sounds like the oil has to be cold (thicker) or the pump spun up to maintain oil pressure, which sounds like an internal (pressure) leak. It doesn't sound fatal, but it doesn't sound right, either; mine have always idled hot with at least 30PSI with a stock pump and regardless of mileage.

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i'm wondering why if when the motor was first fired. At idle it held about 30lbs hot. Not its dwindled down to 15.

Any other suggestions? Could a faulty pump/spring be the culprit? He has a oil idiot light for 15psi and a autometer gauge. light comes on and the gauge shows 15 at hot idle. so we dont think its the gauges fault. Anything else we can check besides pulling it apart? Its been through a couple oil changes with no change in pressure.

thanks.

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Issue still remains, in re-reading this reply.

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First thing I'd do is try another gauge; then cut the oil filter open and inspect the element for bearing material.
Could be bearing clearances too large, oil being aerated, maybe the filter going into bypass. Sounds like the oil has to be cold (thicker) or the pump spun up to maintain oil pressure, which sounds like an internal (pressure) leak. It doesn't sound fatal, but it doesn't sound right, either; mine have always idled hot with at least 30PSI with a stock pump and regardless of mileage.

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i'm wondering why if when the motor was first fired. At idle it held about 30lbs hot. Not its dwindled down to 15.

Any other suggestions? Could a faulty pump/spring be the culprit? He has a oil idiot light for 15psi and a autometer gauge. light comes on and the gauge shows 15 at hot idle. so we dont think its the gauges fault. Anything else we can check besides pulling it apart? Its been through a couple oil changes with no change in pressure.

thanks.

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Issue still remains, in re-reading this reply.

Quote:

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First thing I'd do is try another gauge; then cut the oil filter open and inspect the element for bearing material.
Could be bearing clearances too large, oil being aerated, maybe the filter going into bypass. Sounds like the oil has to be cold (thicker) or the pump spun up to maintain oil pressure, which sounds like an internal (pressure) leak. It doesn't sound fatal, but it doesn't sound right, either; mine have always idled hot with at least 30PSI with a stock pump and regardless of mileage.

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i'm wondering why if when the motor was first fired. At idle it held about 30lbs hot. Not its dwindled down to 15.

Any other suggestions? Could a faulty pump/spring be the culprit? He has a oil idiot light for 15psi and a autometer gauge. light comes on and the gauge shows 15 at hot idle. so we dont think its the gauges fault. Anything else we can check besides pulling it apart? Its been through a couple oil changes with no change in pressure.

thanks.

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If it changed pressure from when it first was run to now, then there is something wrong.

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ok so how do we diagnose everything besides pulling it out and apart? meaning we hate to rip it out and find it was a worn pump drive or something. if also anyone could give us a breakdown of possibilites