Ok I have scoured tons of post to no avail so I need the collective brain power here.

I have a 09 Ram , 5.7 that just broke 270k miles and has been well maintained.

I have a whine coming from my engine that reminds me of the old gear drive timing sets but more airy akin to a diaphragm compressor(similar to a bug sprayer pump squeak on steroids). It doesn’t seem to follow RPMs but I still have to double check that.

I replaced the alternator due to worn bearings and that got rid of some of it and have scoped most of the components and drive train. I haven fully scoped the engine but the sound seems to be coming from under the intake manifold. There is no rod knock, lifters sound good and the engine runs good.

I do have an intermittent run hot issue that pointed to a bad head gasket by failing the coolant carbon test but after fixing the exhaust manifolds it passes that test. Still gets to about 240 temp once in a while and I loose a bit of coolant out the overflow. I also have the common right rear speed sensor issue so it doesn’t go into fuel saver mode. No other codes except for small evap leak and occasionally cylinder 6 misfire.

I was thinking cam bearings but I don’t hear the cam rattle nor does the engine show any other symptoms or throw any codes. I still need to finish scoping the engine to try and pinpoint the loudest location but that’s how far I have gotten with testing.

Ive built and worked on a lot of engines but this has me stumped. None of the usual suspects are the issue. It doesn’t sound like a normal bearing noise. I’m at the point of a full rebuild or a replacement engine if I can’t find a cause.

I’ll update if I can narrow down the source more when I scope the engine again. Anyone have any specific spots to hit with the stethoscope please speak up

last point is that the whine doesn’t start right away but after about a minute idling.

Oil pressure issue just popped up showing pressure as low as 13 at idle and 35 at 75 mph(2000 rpm). Oil changed last week with 5w20 Vavoline Restore and now getting P000B code.

 

Take off the serpentine belt, run the engine for a couple minutes. Does the noise show up?

 

I’m used to using a mechanics stethoscope so I haven’t done this test. I’ll try it probably this evening and post the results.

 

So I took the belt off and some of the whine went away. Put it back on and went over it with the scope again.

The loudest spots are on the intake manifold right behind the throttle body but not the valley right bellow where the VVT solenoid is, the bolt that holds the idler pulley for the belt(I noticed a slight wobble in the idler) the AC compressor near the pulley(ac off) and the lower part of the timing cover.

im now getting the p000b code as well and my oil pressure is dropping to 14 psi at idle and topping out at 30-35 at 2000 rpm.

It’s looking like I have several issues. Oil pump clogged or going out, bad idler pulley, possibly bad VVT and MDS solenoids and AC compressor pulley bearing. Anyone know if the cam gear can make a whine noise? I haven’t worked on a VVT set up before so I don’t know what is involved.

I’ll have to start with the oil pump and probably check main and rod bearings while I have the pan off.

Any advice will be helpful because I know there’s something I’ll miss or forget.