First Dodge, rod knock and losing oil pressure

[benmannej1]

Just bought my first Ram, its a 98 1500 5.9 4x4 Sport with 81k miles

It has what i believe is a rod knock, at least it sounds like one and there is some shavings in the oil it looks like. But once the motor warms up a little it loses oil pressure. If you give it some gas, it will bring the pressure back to ~40.
So could it be something other then a rod knock? or something is bad that caused a rod knock?

Any help would be good, Thank you

Ben

 

[2K10HemiRam]

Rod knock, I've got nothing for

81k is low miles for that truck but your oil pump is probably shot.

 

[MADDOG]

Yeah, that sounds like an oil pump issue.

 

[benmannej1]

how can I tell if it is a oil pump issue?

 

[2K10HemiRam]

What you're seeing is how you tell, at least that's the only way I know how to tell. And how's, maybe the knocking you're hearing is actually the pump? I don't believe the oil pump is hard to do either. I remember looking at a DIY a couple years back on another forum and I being it was just dropping the oil pan, removing a couple bolts, and swapping it out.

 

[benmannej1]

i would like to be sure first. I just dont see how it could have a rod knock at only 81k

 

[05ram4x4]

I'd like to know how this works out. I hear what I think is a rod knock when I first start it. And I hear it when the rpms get high enough. My gauge drops sometimes but i believe that is an electrical issue.Maybe you are having the same problems?

If it IS rod knock...how is that fixed?

 

[SmokedRam]

I'd like to know how this works out. I hear what I think is a rod knock when I first start it. And I hear it when the rpms get high enough. My gauge drops sometimes but i believe that is an electrical issue.Maybe you are having the same problems?

If it IS rod knock...how is that fixed?

It's fixed by a rebuild...


To the OP...how long have you owned the vehicle? It may have been oil starved at some time in it's life, due to a bad plenum, which causes excessive oil consumption. When you drop the pan, inspect the main bearing caps for excessive movement. It could also explain the oil pressure issue too. It might not be the oil pump at all.

 

[benmannej1]

i just bought it, knowing it had some kind of issue.
Im just wondering if it might just be cheaper to buy a used longblock and swap over the good hard parts onto it. If it is a rod knock, i really dont want to see a machine shop bill...

 

[benmannej1]

Or maybe buy a new/reman shortblock? I cant really find any online though

 

[Casper]

I can't address the knock, but I have seen a Dodge oil pump start to fail before.
Your oil pressure guage is the key. In my case during the winter at about 130K I'd start the engine and the oil psi would hang at about 1/4 with valve lifter noise for about 2 mins. Then psi would rise to operating psi--I did not gun it to increase rpm, although I'm sure that would have brought psi up, but probably would have cracked a couple of rings too.
I had been running synthetic oli for a couple of years and on the previous change the shop put their house synthetic in instead of Mobile One, so at at first I thought it was just too low viscosity oil( I remember when the cure for burning oil was using 20W-50 until you could afford a ring and valve job).

I tried one oil change back with Mobil One, but the problem continued, so I had the pump changed at a local car care and tire shop and then traded it in at 140K.