340 oil presure drop

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siegenthaler.16

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was wondering what would cause a 340 to loose oil pressure when it starts out at 60 when cold and then drops
 
As the engine wears the oil will escape through to sides of the various bearings and not reach the sender. When the engine heats up the lose increases. It takes only 7 to 9 psi to turn off a waning light. If you maintain 12 psi minimum and dont hear a valve rattle it'll be fine for a long while yet.
Keep clean oil and filter on it. Good luck
 
I think cold oil, creates higher pressure, then looses some as engine warms up. All my vehicles with gauges does this senario. They claim, 5w when cold/30w when hot? I`m no lubricant engineer, but does it really work as claimed? Anyhow as long as you dont have a significate drop in pressure I would`nt worry. But If yours goes from 60 to 20 or 10, I`d be suspicous. I have a ferd 390 w high volume pump that near burys to 100lb + then drops to 60-50 after warming :-D
 
this is normal

I have a gauge on my 2004 Colorado pickup with 58k on the clock. If I start it up and run at 2000rpm when its around freezing out, I have 95 psi of oil pressure. When warm, it has 20psi at idle.

My duster has about 75-80psi at start up and about 15 at an 800rpm hot idle. Its a little lower than I'd like BUT its not a new engine either. I have over 50 at cruise and its an electric gauge that may be slightly effected by the voltage drop at idle from lower alternator output.
 
siegenthaler.16 said:
was wondering what would cause a 340 to loose oil pressure when it starts out at 60 when cold and then drops
Click to expand...

Before we say what's normal and what's not tell us what the oil pressure drops to when the engine is hot. 10-20 PSI is normal cuss as the oil warms it gets thinner and can escape the bearings it's being pumped into easier hence the lower pressure.

Terry
 
my dad had broke the crank and then replaced it he thinks that the low oil pressure is due to a cracked block or wrong sized bearings
 
All these things mentioned make a difference.
People would remove the thermostat and change to 30W single viscosity oil before trading in a vehicle so it would show good oil pressure for the apraiser.
 
RedFish said:
All these things mentioned make a difference.
People would remove the thermostat and change to 30W single viscosity oil before trading in a vehicle so it would show good oil pressure for the apraiser.
Click to expand...

Noooooo!

You're not saying someone would actually do that are you?
 
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