Oil Pressure Question

[JetBoatRich]

My RV has a 454, when sitting idling the oil pressure goes up. When a Take off it drops down. Slight noise, is this a spun bearing.

[Fiat48]

Hmm, this is kinda like diagnosing cancer over the phone.
Oil pressure up at idle..but goes down with rpm? Or goes down as the vehicle moves forward? (ie. oil sloshing away from the pickup tube.) Or pickup tube broken off. Spun bearing is doubtful, turns into a loud noise rather quickly. You say RV, is this a boat or what?

[Rexone]

Oil bypass stuck?

[Hotcrusader76]

I say it's stuffed up with something as well or maybe it came loose from the pump a little causeing air-leaks (meaning less suction at higher RPM's) :confused: ...
Chew on that for awhile...

[Jrocket]

Oil level low.Check it.J/K :D ....Sounds like a baffle is loose in the pan.When you rev it up does the pressure go up and then back down?Sucking something up against the pickup....or the by pass spring is dusted...I say the spring is dusted. :)

[JetBoatRich]

We have had it for a year, it has 45,000 miles on it. When sitting at a red light the other day the oil pressure went over 60 and dropped down to 50 during normal driving??

[jetaddict]

I can change the Muffler Bearing on it for $221.93 and then we could probably get a better idea what is wrong!!

[JetBoatRich]

jetaddict:
I can change the Muffler Bearing on it for $221.93 and then we could probably get a better idea what is wrong!!I guess the air in the tires should be upgraded to winter air?

[JetBoatRich]

I will just have to mess with it!

[Rexone]

JetBoatRich:
I will just have to mess with it!I'd be suspecious of the oil bypass being stuck, or the spring, or the oil filter being partially plugged with something. The bypasses get gummed up with crap over time and get stuck sometimes. Is there any water in the oil? like from a blown head gasket? If water gets in the oil filter it can have this effect because the filter can't pass it. Other than that and the ideas others have listed, I don't know.
Rich, what's the pressure historically been under normal driving? You mentioned it dropped to 50. 50 is not bad for a stock motor at op temp. Did it use to be 60 or was the 60 a new spike at idle that you hadn't previously seen?
Also, what engine is this we're talking about?

[waterbum]

I would suggest puting a mechanical oil pressure gauge on the engine to confirm that you have a problem.Too many times i've seen electric gauges give false info. Just my .02 Bum

[Rexone]

waterbum:
I would suggest puting a mechanical oil pressure gauge on the engine to confirm that you have a problem.Too many times i've seen electric gauges give false info. Just my .02 BumExcellent suggestion as a first step in diagnosis. I've seen many electric gauges and senders fail and do wierd stuff too. Also check the connections on both. A dirty or oily terminal connection at the sender can cause strange readings. :)

[JetBoatRich]

The oil pressure was always at around 50, maybe a little less at red lights. A buddy told me if the oil pressure goes up like that, spun bearing. And because of that we hear a slight piston noise. The noise is inconsistent, sometimes not at all.?
Thanks crew!