i bet youre oil pump is fried.
oil filter is clogged meaning no oil to the engine.

 

Well, that's the lesson one learns when one fails to do proper maintenance.
If he learned, he'll change it / have it changed every 3k, as he should've done all along.

I wouldn't waste my time with synthetic just yet, well... Ok, you can, but it will cost you.

What I would do is run the engine to op-temp, then check the dipstick and if it's black oil, change the oil and filter again.
I can almost guarantee (no, actually, I *DO* guarantee) that the oil is black again right now!
If the engine has been run to HOT, go check that dipstick and see if I'm lying.
If it's black (I'm telling you it is), change oil + filter.

Yes... Because when fresh oil heats up, it dissolves and absorbs sludge, turning it black.
I've seen it more than once, JUST changed the oil and sure enough, it's black again not 30 minutes later.

Then, run it to op-temp and drive it some, and check that oil again and again.
Soon as it turns dark-to-black, change it again.
Keep doing that until it hardly turns color no more.
You'll likely have to change it frequently 5-6 times, hopefully less.
Then, once it stops turning color fast, you can go the usual 3,000 miles between.

Btw, you could run it for 50-100k miles on one change but you got to use Amsoil.
Likely a waste until you get the sludge out.

As for damage, if there's no blue smoke coming out the tailpipe during normal driving, you might've got lucky.

But I would switch to synthetic, just in case your uncle did not learn, and really, you can do a lot more to restore power, likely nothing's been done.
Try spark plugs, wires, cap + rotor, trans fluid + filter, fuel filter, pcv valve, breather cap, air filter.
That's for starters, I'd get high performance stuff if he really wants to fire up tires, but really his driving record would fare better if you didn't.

 

i have seen this with cust vehicles before. they didnt run any more. i have seen sludge that hid rocker arms like 6 month old jello.pull the oil pan and valve covers remove as much sludge as possible, replace the oil pump and pickup screen. remove rocker arms and push rods and soak them in mineral spirits/gas orsomthing like these. you need to make sure there is no sludge in the push rods or the valve train will fail. i would alsoreplace the lifters.the mopar performance ones are only like $120.00, much better than oem price. but after all this, the engine will probably blow anyway. or just start building a new one or get a mopar performance 360 mpi short block and have the heads rebuilt.

 

If you just changed the oil, it is nasty already. Get a can of "motor flush" and follow the directions with it, which requires youto drain and replace the oil and filter. Then change the oil every 1000 miles or so for the next few times - if it is really bad flush it again. If it was running better with the sludge in it - it's probably due to the sludge building up on the cylinder walls which increased compression. Like the other guy said - do a tune-up with a new cap and rotor, plugs, and wires. You might get that power back. If not - oh well. Anyone who treats a motor like that doesn't deserve to drive one, much less to "light up the tires"......[:@]

superdak05 - you really shouldn't post "jokes" like that on here without stating at the bottom that it is a joke and NOT to do it. Remember that many people on here are NOT mechanically inclined, and someone might have seen your post and thought that the water idea was the best fix for the situation, and would have done it.......

 

Dont judge the sludge build up from the rubber substance on the dipstick. It comes from the factory witha rubber coating on it. Did the dipstick read the correct levelafter the oil change? If it did, the oil pan cant be to bad.40 psi is still within the factory specs.

With 139,000 miles I'd do a commpression check. If its low, it could explain why your uncle cantlight up the tiresanymore.

 

these guys hit on everything but one. use a ph8a filter or equivalent size its bigger and therefore wil hold more oil and filter better. i think the motor needs it!!!!

 

The exhaust has no blue smoke and the oil level on the dipstick is correct after the oil change. The air filter hasn't been replaced in 30k miles and i think that might have a part in having a loss of power.

 

my mother killed her last car by not changing the oil in 75k. changed it a few times while under warranty....then forgot about it forever. My luck I killed it on a 3 hour highway trip.

 

Would engine restore do anything? If i use engine flush and the compression drops, will the truck still be able to be driven or even run? If i break it, my uncle is going to be really pissed at me and will make me pay for it.

 

My advice,dont do anything. His truck, his problem. Sorry, but this could causesome hard feelings between you two.