4.7 oil pressure next steps

[BrewKrew]

I’m brand new here, and I know this is an old tired topic, but I’ve searched for further answers with no luck. This is going to be long winded. I apologize in advance.

Another caveat is: the only mechanical knowledge I have is what I have learned from the internet while doing all my own maintenance on my vehicles over the last few years. I’ve never actually gotten inside an engine like I may have to do now.

I have a 2005 Ram 4.7 4x4 that has 263,100 miles. It was my wife’s grandpa’s truck since new, we’ve had it for 2 years since he passed away. It has a lot of issues but we want to keep it running because of it’s sentimental value. I would like to think that the oil changes etc were kept on top of, but the body was not, so I’m not sure. When I got it, it had 255k, and the oil pressure warning came on regularly according to gpa’s wife. I immediately did an oil change with Valvoline extra high mileage 5w-30 and put Lucas oil stabilizer in it, and I installed a new oil pressure sensor. The warning didn’t come back for a little while, then it gradually made its way back. I ran seafoam in the oil, changed it again, adding the Lucas stabilizer again. The warning went away until I was nearing another 3k oil change interval, so I did seafoam again, changed the oil, without stabilizer this time, thinking maybe it’s thickness was contributing to plugging stuff up. Since then, the low oil pressure warning has been consistently coming up when the truck is at operating temp, every time I come to a stop. The pressure goes back up when I give it gas and/or take off again. Everybody says to hook up a mechanical oil pressure gauge to verify the warning light, so I did. I got around 75 psi at cold start idle, 70-80 psi while accelerating, and 18 psi at full temp idle. This verifies that the sensor is working fine, since the warning comes up at stops and goes away with acceleration. I let it idle for another 10 mins after this test and the pressure dropped even further to 12 psi.

Also might be worth mentioning that this truck does not leak or use any oil, I’ve checked the oil numerous times in between intervals and it’s never been below the minimum level.

Now, finally, we are to my questions:

Does anyone know of a tutorial video on how to remove and clean the oil pickup tube? I’ve googled several times with no luck. I could probably figure it out, but I’d much rather have a visual guide.

I’ve heard that worn bearings could also cause this issue, so is it reasonable and/or feasible for me to check the condition of the bearings while I have the oil pan off? If so I would need a visual guide for that too.

When I put it back together, should I put Lucas Oil High Mileage Stabilizer in the oil again, since that seemed to help the warning light? Or will it have adverse effects with the pickup tube?

Thanks you for your patience and advice.

 

[Daw14]

You need to remove the oil pan to gain access to the oil pick up.

The pickup has a wire mesh screen which is likely clogged with sludge, I’m guessing you figured that out.

If you pull a valve cover to look into the engine, that would give you an idea if maintenance was regular. Or it will be caked in crusty dried oil . If that’s the case your pickup is clogged .

Chances are the bearings need replaced along with a lot of other wear items.

With that high mileage timing gears and chains , tensioners are all due .

Probably time for a rebuild or replace.

 

[BrewKrew]

That’s what I’m afraid of, if I need to spend thousands on this truck to keep it going, it brings up the question of whether it’s worth it or not. We can technically afford to pay for these repairs or buy a different truck outright, but it wasn’t exactly in our plans for this year. For now I just want to fix the oil pressure issue and see what info I can gain on it’s condition while doing so.

 

[turkeybird56]

OP that many miles rebuild/replace coming. Might be cheaper for a crate motor but given year/age u not gonna find much if any to hook up to old tech. Your best bet may be a reman motor but make sure U do yer research before plunking down a lot of $$$$$.

 

[turkeybird56]

Maybe u can get away with dropping pan, check out oil pump and pickup. U might wanna run Seafoam thru motor than change oil also. IMHO quit running alll day Lucas stuff. There is a better product to run through motor to clean a lil just not remember name. All above IMHO.

 

[Green_Manalishi]

Forgive me, but you may have a solution in search of a problem. Seems to me it's running just fine, despite low pressure at idle. I'd drive it until you have to do something, which is a destination you'll arrive at eventually. Kinda reminds me of myself at my age...

 

[BrewKrew]

Seems to me it's running just fine, despite low pressure at idle. I'd drive it until you have to do something,…

Certainly possible I’m overthinking. The engine sounds totally normal to me even when idling. It’s just that the warning light stresses me out, and I don’t want to let the problem go until it leaves me stranded somewhere and/or the engine is screwed beyond help. I hate having that feeling hanging over my head, but TBH I might just be that way regardless of what vehicle I’m driving

 

[jws123]

I have worked on countless 4.7s with this issue chased and chased it like you many times. rarely is it ever the pickup tube at this mileage at the end of the day the main bearings are worn your never getting that pressure back you need a engine not even worth fixing the engine in it just go find a wreck and swap the engine.

 

[BrewKrew]

…the main bearings are worn your never getting that pressure back you need a engine not even worth fixing the engine in it just go find a wreck and swap the engine.

Can I physically or visually verify that my bearings are shot before I drop that much money? And for that matter, verify that the bearings are good in the engine I’d be swapping in?

And if the truck has other issues, (like rear end needs rebuilt, it clunks and lurches when you put it in D or R, it’s cab corners and rear wheel arches are rusted, suspension is shot, etc) then do I just leave it and plan on buying a different truck when this one dies?

 

[Daw14]

When you remove the oil pan is when you will gain access to the crankshaft , along with the main bearing caps and rods. Now you can remove bearing cap’s exposing the bearings .

 

[jws123]

Can I physically or visually verify that my bearings are shot before I drop that much money? And for that matter, verify that the bearings are good in the engine I’d be swapping in?

And if the truck has other issues, (like rear end needs rebuilt, it clunks and lurches when you put it in D or R, it’s cab corners and rear wheel arches are rusted, suspension is shot, etc) then do I just leave it and plan on buying a different truck when this one dies?

If the rest of the truck is in bad shape then yes not worth fixing as the truck would never be worth anything with 200k+ miles

 

[jws123]

When you remove the oil pan is when you will gain access to the crankshaft , along with the main bearing caps and rods. Now you can remove bearing cap’s exposing the bearings .

No not on a 4.7 the whole bottom has to be un bolted it splits its a PITA not possible in the truck However you can inspect a rod bearing.

 

[Daw14]

No not on a 4.7 the whole bottom has to be un bolted it splits its a PITA not possible in the truck However you can inspect a rod bearing.

I was thinking I should confirm this before posting but let it fly . Thanks for the correction.

I know the old stuff pretty well , but gotta read on some of the things that aren’t older than 25.

 

[Sherman Bird]

I’m brand new here, and I know this is an old tired topic, but I’ve searched for further answers with no luck. This is going to be long winded. I apologize in advance.

Another caveat is: the only mechanical knowledge I have is what I have learned from the internet while doing all my own maintenance on my vehicles over the last few years. I’ve never actually gotten inside an engine like I may have to do now.

I have a 2005 Ram 4.7 4x4 that has 263,100 miles. It was my wife’s grandpa’s truck since new, we’ve had it for 2 years since he passed away. It has a lot of issues but we want to keep it running because of it’s sentimental value. I would like to think that the oil changes etc were kept on top of, but the body was not, so I’m not sure. When I got it, it had 255k, and the oil pressure warning came on regularly according to gpa’s wife. I immediately did an oil change with Valvoline extra high mileage 5w-30 and put Lucas oil stabilizer in it, and I installed a new oil pressure sensor. The warning didn’t come back for a little while, then it gradually made its way back. I ran seafoam in the oil, changed it again, adding the Lucas stabilizer again. The warning went away until I was nearing another 3k oil change interval, so I did seafoam again, changed the oil, without stabilizer this time, thinking maybe it’s thickness was contributing to plugging stuff up. Since then, the low oil pressure warning has been consistently coming up when the truck is at operating temp, every time I come to a stop. The pressure goes back up when I give it gas and/or take off again. Everybody says to hook up a mechanical oil pressure gauge to verify the warning light, so I did. I got around 75 psi at cold start idle, 70-80 psi while accelerating, and 18 psi at full temp idle. This verifies that the sensor is working fine, since the warning comes up at stops and goes away with acceleration. I let it idle for another 10 mins after this test and the pressure dropped even further to 12 psi.

Also might be worth mentioning that this truck does not leak or use any oil, I’ve checked the oil numerous times in between intervals and it’s never been below the minimum level.

Now, finally, we are to my questions:

Does anyone know of a tutorial video on how to remove and clean the oil pickup tube? I’ve googled several times with no luck. I could probably figure it out, but I’d much rather have a visual guide.

I’ve heard that worn bearings could also cause this issue, so is it reasonable and/or feasible for me to check the condition of the bearings while I have the oil pan off? If so I would need a visual guide for that too.

When I put it back together, should I put Lucas Oil High Mileage Stabilizer in the oil again, since that seemed to help the warning light? Or will it have adverse effects with the pickup tube?

Thanks you for your patience and advice.

I think you are putting Band-Aids on where stitches are needed.
Number one: The oil pan gasket on that engine is integrated with the windage tray, which bolts to the main caps. It is difficult on a good day to get to. THEN, the bolt which retains the pickup tube to the oil pump is in a very tight spot, and is hard to access in chassis.

All that aside, you have worn out rod and main bearings. Truth be told, it likely has faint a low end thud.

Me thinks you should consider a reman engine!

 

[Wild one]

Another band-aid is to switch it over to something like a 20W-50 oil.You never said what filter you're using,try a differant filter brand,and see if anything changes,sometimes a cheap filter can cause issues.
If it's making it to 3,000 miles after an oil change before the warning light comes on,makes me wonder about the quality of the filter,and whether that crappy Lucas additive is plugging it .

 

[Dodge 1500 4X4]

Or a Streight 30w motor oil, for worn mains and rods, that Lucas crap isn't helping you at all, outside of that just run it, sounds like rust is an issue.

 

[BrewKrew]

Update: in the past couple weeks the truck has started shuddering/vibrating at idle, particularly right after startup. It has happened once or twice before, but never this frequent. Just like the low oil pressure, it goes away when I give it gas. Also, last night, I had the battery gauge stay at 0 with the “check gauges” warning. That’s the first time that has happened.

I want to try thicker oil and a better flowing filter, but now I’m afraid this thing won’t even make it long enough for me to try that.

I may be doing some research or posting other questions related to buying a different truck soon.

 

[BrewKrew]

Update 2: the fuel pump went out on my car that I usually drive to work, so I went to Walmart and got some Mobil1 15w-50 full synthetic and a Purlator Boss, threw em in my truck, and drove it 40 miles to work. It’s run great so far, no oil pressure warning, minimal vibration. The battery gauge still shows 0 but I’m guessing that’s unrelated. Thank y’all for the help and band-aid suggestions. I’m sure the truck is still on it’s last leg but it’s working in a pinch thanks to you guys.

 

[Grams]

Lucas and other snake oils are NOT what that high-mileage engine needs. That 4.7 needs lubrication. Those are NOT lubricants.
And the oil pickup tube and screen are also not the problem or you wouldn’t have good oil pressure at higher RPMs.

That engine is a good engine…the last one designed by AMC before Chrysler acquired them.

The engine needs overhaul, plain and simple.

To put that off until the very last possible …. just use a heavier-weight or straight-weight motor oil…. but eventually it’s gonna need rebuild, plain and simple.

 

[Sherman Bird]

Lucas and other snake oils are NOT what that high-mileage engine needs. That 4.7 needs lubrication. Those are NOT lubricants.
And the oil pickup tube and screen are also not the problem or you wouldn’t have good oil pressure at higher RPMs.

That engine is a good engine…the last one designed by AMC before Chrysler acquired them.

The engine needs overhaul, plain and simple.

To put that off until the very last possible …. just use a heavier-weight or straight-weight motor oil…. but eventually it’s gonna need rebuild, plain and simple.

AMC never designed the 4.7. It's a near carbon copy of the Mercedes 4.5L V-8 from the 60's/70's! Came out when Chrysler was owned by Mercedes (1999).