question about changing the rings on a dodge 2500 , 5.9L magnum , 1998

Which ring? If you mean the rings (bearings) that hold the bottom of the piston rod to the crank shaft, probably easier from the bottom.

If you mean piston rods (which hold the compression in) you'll need to compress the rings to get the piston into the cylinder. I don't know if you can use a ring compressor from the bottom. But, I doubt it. Never heard of anyone doing it.

I presume you, or your garage has tested the compression. It would be unfortuate to pull the engine apart and replace the wrong component.

it is the oil ring on the piston

pat

yes it was tested at the garage , and the problem that the dealer is telling is that i used syntetic oil , and i had a crack head that leak prestone in the oil , and they tell me that because it was syntetic oil , the mix of oil and prestone did a kind of caramel like goo that is stuck inside or in the back of the compression ring , and those ring are stuck compress in , and ther is no way to unstuck them with any additive , so i have to take them out to change them

pat

If you had anti-freeze in your oil you'd better take a good look at the bearings before you do much else.

Roy

Drain the oil and refill with ATF and let it idle for a half an hour. Then drain, replace the filter, and refill with oil. Change your oil and filter again in a couple of weeks.

beekeep

To replace the rings, you have to remove the pistons. That has to be done from the top. The whole job can be done without removing the block from the truck. It's a very big job. You have to remove almost everything from the engine, leaving only the cam, crank, and front cover. Not something the average home mechanic has the tools, aptitude, or desire to do.

Heck of a lot cheaper than an engine rebuild. ATF is loaded with cleaners and other agents, and tends to clean our the crud from engines. I've known folks to put a quart of ATF in a day or two before an oil change, to loosen the crud.

Let us know if it helps.

Stop the music! Did I miss something?? You have a cracked head, and water in the oil, and a dead cyl? Did you replace the head, then do the compression test?? If so post the numbers. Something seems a bit off here. As I said before if the oil and anti-freeze has run for very long you might have wiped a bearing. If that is the case you might want to explore all your options.

I agree, if there was significant water in the oil then there may be damage to the bearings, the cam, and who know what else.

I can't say for sure that it will work. I've used ATF to clean out clogged up lifters so why not try it on the oil rings? Considering what he is thinking of doing, I would give it a try first. What does he have to lose other than a few bucks for filters and fluids?

Paraphrasing Karl Marx, I think it was.

Mechanics of the world, unite! You have nothing to lose but your sludgy piston rings. You have nothing to gain but a good running vehicle.

Beekep, that's wise advice, and thanks for sugesting it.

Agreed, I've used atf for lifters and it worked on a valve once. With what he has going, doubtful atf will move it. I've seen water dilution to the point that you have to scrape it off. Perhaps a quart of diesel fuel. Let it idle for a few minutes, shut it down, drain it, and repeat a few times. Leave all the fill caps and breathers open so the fumes will escape. Do not let it get hot!

Warning! If the bearing's are wiped and get hot the addition of diesel fuel can be real dangerous.

Honestly with a cracked head and ring problems I'd be looking for a good replacement engine.

OTOH it may not be an oil ring problem at all. If he believes that is the problem because he is experiencing excessive oil consumption he may have just sucked in a plemun gasket. It's easy enough to check, just pull the oil cap off with the engine running and see if you have suction at the hole.

beekeep

Could very well be. But it is sorta hard to figure out what's what with this one.

A problem with an oil ring wouldn't show up on a compression test. Water in the oil /might/ cause a ring to stick, but the bearings would be wiped before you noticed a consumption problem. Synthetic oil wouldn't be the root of the problem, if anything it would have saved some components. The OP is either clueless or the whole story is bunk.

I think your last sentence tells the story.

Roy