No oil pressure at idle

[jws123]

I have thought of that LOL. I don't think I could do that though, I've done so much to this truck already, my last project was rebuilding my rear diff which wasn't fun (Its been 500 miles since that), so I'd rather spend more to keep it honestly. I was planning on doing a tear down on the 5.7 and putting new seals and addressing any issues it might have. If I get the parts truck I just take its motor mounts and switch them to mine, same with brake lines and ac lines, pcm, harness and all the other parts. If I were to get a 5.7 parts truck, where would yall look and what would you offer?

look on facebook and by motor mounts i mean the frame where it mounts up you may have to weld them in another spot on your truck to fit a 5.7

 

[HemiLonestar]

I think at this point I'm going to buy a parts truck with a 5.7 in it, this way I can do a swap and have all the needed parts. Should be cost affective as well from the one I'm looking at, it has right around 100k miles and he's asking 3k for the truck since its got a blown trans.

I have a 2003 5.7 (still runs great at almost 200k, just shot trans) you can come up and get lol.

 

[pscarbor]

You can get a reman'd 4.7 from Powertrain for $3500. Comes with a warranty and everything.

Dodge RAM Jeep 4.7L V8 Remanufactured Engine - 1999-2004 16 tooth reluctor - Powertrain Products

Dodge RAM Jeep 4.7L V8 Remanufactured Engine - 1999-2004 16 tooth reluctor by Powertrain Products . OEM quality, backed by the industry's best warranty.

www.powertrainproducts.net

 

[Dusty]

I've got a 2003 4.7 ram 1500. I recently did a coolant change since the previous owner put in the wrong coolant, and as I was attempting to bleed the system my oil pressure gauge would go to zero at idle once it was warmed up. I mentioned the coolant change since I feel like that might have something to do with the issue since I've never had anything but normal pressure until then. I've already done the obvious thing of switching the oil pressure sensor, and I noticed that I was just under a quart low on oil from various leaks, and a missing PCV valve that I just fixed. I topped off the oil hoping that was the issue but sadly it was not.

Right now, I'm planning on getting a mechanical gauge to ensure that I really am losing oil pressure (the truck runs funny after driving from a stop, and that goes away once the pressure comes back, so I'm prettttty sure the readings correct). I'm then going to remove the oil pan, and make sure the pickup tube isn't clogged, and replace the oil pan gasket at the same time to stop that leak. This is unless its bearing failure, dunno what I'll do then. Just looking for some advice, maybe someone's had this issue and its a problem I'm not aware of.

The only code I have one the truck is a PO499 "Evap Emission system vent valve control ciruit high" code. Just on the odd chance that that's related which i doubt it is. TIA

If I read this correctly, you had good oil pressure until you did the coolant change? There's seldom a natural occurring coincidence, although it does happen.

While you were doing the coolant change, did the motor get a sudden rise in temperature/coolant pressure? Did you use a coolant system flush?

The only weakness in the 4.7 that I could ever tell was a propensity to lose a head gasket or warp a cylinder head if overheated. I have also twice in my life seen a pickup screen so clogged that would reduce oil pressure at idle but see an increase at higher RPMs. I've seen a couple of these very high mileage 4.7s torn down and the mains and rods were still looked pretty good. Of course, that will be dependent on previous maintenance.

Considering a rebuilt motor or quality rebuilder is a good idea if you think the truck has value enough to be worth it. If you select a rebuilder, insist on good block prep: boiling out, checking all mating surfaces, etc.

Just my thoughts.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 124133 miles.

 

[Trashy2121]

It doesn't hurt to verify the pick up tube, but I would think the real oil starvation would happen when you started acceleration. What oil weight are you running?

 

[T Ram 20]

The pressure comes right back to the normal range right about say 1500 rpm, goes straight to zero the second it idles. It being lower than normal permanently is what signifies bearing failure?

Try replacing oil filter might be bad

 

[Tominator223]

I’d change the filter & put a quart of diesel , seafoam, or b12 chemtool. Start it let run while lightly revving it til up to temp or psi drops. Let cool. Do it again. Then drain & change oil. See what it does then. If the bearings are gone already it won’t matter much. If it’s slugged up it'll get psi back. If it smokes already you may have an oil pan full of valve seals. Like I said if it’s already gone what difference dim. Jmo