Coked Piston Rings?

My '88 Escort (518,500 miles) has been using more oil than usual lately. I know it has some sludge problems and think maybe the rings are coked. Anyone have any suggestions of what might be used to clean this up without engine dis assembly. The car can still be driven like this and the car isn’t worth the time and effort to dis assemble everything. Would it hurt to pour an ounce or two of Marvel Mystery Oil directly into the cylinders and let it soak for a few hours? Would this likely help break it loose and clean it up or more likely to cause worse problems?

The Marvel oil or any light viscosity oil or trasmission fluid might help. I have done that soak down many times on all sorts of engines and never seen any damage done. The usual procedure has been to remove all the plugs, pour several ounces of oil into each cylinder, lay a shop rag loosely over the plug hole to catch the excess and turn the harmonic balancer a few revolutions. Whenever putting an engine away for the winter or longer I do that. There’s a smokey startup but that’s no big deal. Isn’t 500,000 miles pushing the limits on that little engine.

There are additives in a bottle at the parts store that are sold specifically for this purpose. It’ll do absolutely no harm to try some. I doubt of pouring Marval Mystery Oil in and letting it sit will do anything. It isn’t a solvent.

But I gotta tell ya, at 24 years and 518,500 miles, it may be futile. In addition to wear on the cylinder walls and rings, rings lose their tension. When they’re originally installed, they have spring tension against the cylinder walls. After being heated up and pouned on million and millions of times, they lose this tension. They become a squeegee without pressure.

I suspect the problem is not coked rings. I suspect the problem is tired old rings, beaten down with age, in worn out cylinders. But try the additive anyway. You’ve nothing to lose.

Congratulations, by the way. That mileage is one heck of an achievement.

An oil product may soften the coke, but as soon as you start the engine, it too will coke as it has no where to go. Use a solvent product instead, like SeaFoam or kerosene.

I agree the cylinder walls and the rings both probably have significant wear contributing partially to the oil consumption, but since it seems to have increased noticeably over just the last few thousand miles and the engine has had some previous sludge problems I thought maybe the rings were also coked.

Do you all think Sea Foam would be a better option? Could the Sea Foam be poured directly into the cylinders? Probably more cleansers. When it warms up, I plan to pull the oil pan off and clean it out and do an oil/filter change, so I could try any cleaner prior to removing the oil pan and doing the oil change.

As far as the engine having the high mileage, it still runs good and I get about 40 MPG gas mileage, the only problem is the oil consumption. I checked the compression on it at around 500K miles and the compression was still 145-155 PSI across the board.

There are various products on the shelves. I’m reluctant to suggest a brand name, since I don’t use them. They’ll tell you on the bottle that they’re for decoking engine insides.

I’ve used Seafoam many times to decarbonize coked up piston rings with success.

Get the engine up to operating temperature and shut the engine off. Remove the vacuum hose from the brake booster. Adapt a hose that’ll fit in the brake booster vacuum hose and into the can of Seafoam. Take a pair of pliers and pinch off the hose. Have someone start the engine and bring the idle speed up to 2,000 RPM’s. Now slowly unpinch the hose so the Seafoam gets drawn into the engine. Keep the RPM’s up and pinch off the hose when required to prevent the engine from stalling. Once all the Seafoam has been drawn into the engine, shut the engine off. Reinstall the brake booster vacuum hose. After a half hour has past, restart the engine and bring the RPM’s back up to 2,000 RPM’s. Keep the RPM’s at 2,000 until the smoke out of the exhaust clears up.


If the rings are worn, stuck due to past overheating, or the engine has glazed and/or egged cylinder walls then no additive will help.

The compression at approx 150 is on the way down but that’s to be expected. It’s amazing the compression is that high considering the total miles on the engine.

I don’t think sucking it (sea-foam) into a running engine will do ANYTHING except blow 98% of it out the exhaust and make a lot of smoke…

Rotate the engine to TDC, then 90 degrees more, to position all the pistons at mid-point in their bores…Remove the plugs and introduce 3 or 4 ounces of Sea-Foam or Rislone into each cylinder. Let that soak overnight. Turn the engine over by hand to clear the cylinders, then spin it with the starter, install the plugs, and fire it up…After one drive cycle, I would change the oil…

Keep the ideas coming. Right now I’m not driving the car much, waiting on warmer weather so I can get outside and work with it trying to give the engine a good internal cleaning, pull and clean the oil pan and do an oil/filter change. At the mileage I’ve got out of this engine and the condition of the rest of the car it’s no great loss or disappointment if nothing helps, I’ll just continue to drive it as is until the end.

I like Seafoam but use it at night or call the fire department first. It’ll smoke like crazy and all the neighbors will think your garage is on fire.

What does more oil than usual mean? Eg 1qt/1000 miles or 1qt/500 miles etc.

Some of those products can be $$$$ and will you buy a few cases of really inexpensive motor oil which is all this car needs.

Raj asked an excellent question: how MUCH oil is it using? We’re all answering based on the assumption that the usage is dramatic. Is it?

The rate of consumption is about 1quart/800-1000 miles. I’m not going to spend a fortune on the car but thought trying an $8 can of Sea Foam would be worth trying. I’ve even got a partial can in the garage now where I used part of in my motorcycle last summer.

That’s nothing! Most auto makers consider a quart/1000 miles on their NEW vehicles as normal consumption.


I agree wholeheartedly with Tester. Try some additive if you’d like, but man, if I had an engine with that kind of mileage on it and that’s all it was burning I’d just keep doing whatever I was doing, and wouldn;t mess with it. I might even put together a seminar on how to make an engine last forever and use the vehicle as the star attraction.

LOL, Moutain…

I had a dealer who put a 400,000+ mile used Hyundai he took in on trade on his showroom floor, to prove the car could do it. He said he sold more cars off that one, that the investment he had in it was 100% worth it.

Along those lines, there’s a Toyota dealership not far from where I live that has a mid '90s Camry with a lot of miles on it. I don’t remember exactly, but I think it’s in the neighborhood of half a million miles. They sometimes post a picture of that car in their newspaper ads with an invitation to come in and test drive it, with a dollar sign and NOT FOR SALE! where the price would be. It wouldn’t surprise me if they have a lot of money wrapped up in that car to make it drive well and be a longevity showcase for potential customers.

Any car can accumulate a lot of miles, it just depends on the care it receives and how badly the owner wants to keep piling on the miles. I once worked on a Chevy Suburban that still looked, drove, and even smelled like a brand new truck, but the odometer showed 481,000 miles. The owner said it was legit, and that he just takes good care of it and has had no major repairs needed to date, unless you consider tires and brakes to be major repairs. I don’t.

My '89 Toyota pickup had 338,000 miles on it when it got totalled by an errant Hyundae. I miss it. The engine & drivetrain were all original (except the timing chain and peripheral assemblies like the alternator and starter) and it still ran great.

The 22R Toyota engine is legendary…Too bad they no longer make it.