concretehauler

started losing oil presure little bit at idle ,changed oil. It was black and thinned, probably diesel. After oil change oil pressure came back strong but was short lived. Oil a mess again. Truck has 198000 miles , no engine work done, first promblem.

phox_mulder

How the Diesel is getting into the oil is heavily dependent on what year your truck/engine is.

And, are you sure it is Diesel?
Have you had an oil analysis done?


phox


Oh, and seeing that this is your first post here, Welcome!
You'll find a lot of knowledgable folk hang their hats here.
Myself, I don't wear a hat, but keep the hat wearers in line.

dalton4

I would also be checking the lift pump if the engine is running smooth and appears to be getting even fuel to all cylinders. The lift pump is a mechanical pump and an inside pump leak could put fuel into the engine.

Rammer64

It may also be a BAD injector(S)

Geico266

Welcome! Please fill out your signature so we know what truck you have.

When you check the oil is the level high?

Mopar1973man

just guessing....

It sounds like a bad lift pump on a 1st gen engine... (Let see what unfolds...)

dalton4

concretehauler's profile page showed the truck as being a 96.

concretehauler

96 , 2500, 4x4, 5 speed. engine running a little ruff , starting to lose power on takeoff. oil change only lasts about a week before pressure is gone. Starting to lose her, help. Scared to go to the dealership

wannadiesel

I'll add a third vote for a bad lift pump. It's about $130 and no harder to change than the fuel pump on an old gasser.

boiler-rat

What is the average life expectancy of a 1st gen. lift pump?

wannadiesel

Beats me. If you're in doubt, replace the thing. The 1st gen pumps are around $40. It's a diaphragm pump just like an old gasser, prone to the same problems. The 2nd gen is a piston design, puts out a lot more pressure and lives longer - but it costs 3x as much.