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How does a mechanic do a ring job?

One of the callers in this most recent show had a 1984 Ford F150 going through about a quart of oil every 150 miles. Tom and Ray said the car needed a ring job.

Just curious. What’s involved when a mechanic does a ring job? Is the engine left in the car, and all the work done by removing the oil pan; i.e. from below? Or is the engine removed, put on an engine stand, turned upside down, but the work still done by removing the pan? Or does the cylinder head have to come off too to replace the piston rings? It seems like a ring job could be done, the crankshaft it seems like it would have to come out, but without removing the head; just curious how it is commonly done is all.

@GeorgeSanJose there’s no way to do a ring job without removing the pan and head.
You have to take measurements and determine what size rings you need.
The crank doesn’t absolutely have to come out, but you have protect it from any debris when you’re honing the cylinder walls.
The preferable way to do the job is on an engine stand, but some crafty guys do it installed.

Not for the faint of heart!

A “ring job” is an out of date term. It was a common job, especially on in line engines from Henry Fords Day until the 60s. Most independent shops did complete ring jobs and polished the valves and there were travelling machinists who did the work at used car lots repairing the engine only as needed. They could even turn the crankshaft down and polish it from under the car. If a cylinder was not galled ‘10-Up’ rings could be installed on weak cylinders to increase compression and reduce smoking and oil burning without machining the cylinder. A quick patch job, run the clock back to under 60,000 miles and a clunker could become a cream puff over night. Today the engine compartment on even the most basic models makes such a project totally unrealistic.

@RodKnox nobody said it was easy.
Like I said, that kind of major work is best done using an engine stand.

There are ways to do a ring job without removing the engine. But it’s a cheap way just to keep the vehicle running until a proper repair can be done. If you need new rings there’s a chance you have cylinder wall scaring. Just replacing the rings won’t cure that problem.

Without getting into too much detail - You drop the pan…remove the heads…and then unbolt each piston rod from the crank…then push the piston and rod out the top…Replace rings…and put it back in…then repeat for all pistons.

My dad had 88 f150-302. Had oil burning issue. Warranty replaced rings and valve guides. Dealer did it in 2 days. Basically stripped motor down to nothing. Had to completely strip down heads and pull pistons. Must have been a big pile of parts on work bench.

Very few mechanics do ring jobs anymore; it’s usually cheaper to just get a rebuilt engine since ring jobs nearly always mean valve jobs as well and often bearings.

The last car I had a ring job done on was a 1957 Plymouth flathead 6 in 1964. That cost me all $75 including having the valves ground.

Cheap ring jobs are still done. It’s far cheaper and easier to replace a set of rings then replace an engine. But doing it that way is NOT the proper way. A proper ring job requires removing the engine and having the cylinder honed. And doing it that way is very expensive.

A cheap ring job is how I got my first car ('65 Mustang with a 170 cid 6) on the road. My sister had blown the #6 piston (nice hole in the middle, wish I had kept it!). I did just as @MikeInNH describes, the car then worked fine for several more years. Burned some oil, and the #6 plug required attention, but it got me and my brother through high school. And I learned a lot in the process.

I should point out one huge difference between ring jobs in the '50s and ring jobs on modern cars…the engine orientation and space around the engine. Okay, that’s two huge differences. The point is that I’m not sure most transversely mounted engines could be done without removal from the vehicle. Although I’m sure the '84 F-150 that was the subject of the call could be.

I agree that it’s an obsolete activity. By the time the rings & cylinders need doing on a modern engine, the rest of the engine is pretty tired too. It’s no longer a “weak link” in the designs.

I remember back in the late 1940s through the early 1960s, the oil pan could be removed to allow ring replacement on some cars and this couldn’t be done on other cars. I know that on Studebaker 6 cylinder engines from 1947 through 1952 the pan couldn’t be removed without pulling the engine. On the other hand, the 6 cylinder Chevrolet engines through 1960 the pan could be removed by dropping the tie rods and jacking up the engine. I think that the old Ford flathead V-8 engines would allow the pan to be removed without pulling the engine.
I learned the hard way the difference between a ring and valve job and a proper overhaul. I bought a 1955 Pontiac in 1962 from a Rambler dealer whose service department had overhauled the engine. It was a bad purchase. The cylinder walls had be honed, the ridge removed at the top of the cylinder and the valves ground. The car didn’t use oil. However, on the 1955 Pontiac the oil filter was an option and the one I bought didn’t have that option. Apparently, there was sludge in the engine and the sludge would get into the studs on which the stamped steel rocker arms were mounted. The engine would then chirp. I had the studs pulled and cleaned out. I replaced the hydraulic valve lifters as they had not been replaced. Even so, the chirp would return when I drove on a trip of 200 miles or more. I never did solve the problem.
Had the job been done properly, the engine would have been pulled out the chassis, stripped down and all oil passages cleared out. The lifters would have been replaced. The crankshaft would have been miked and the throws reground if necessary. The camshaft would have been examined for excessive wear and the timing chain replaced. At any rate, I did learn the expensive way the difference between a proper rebuild and a “ring and valve job” which really means a sloppy patch.

Okay, that's two huge differences. The point is that I'm not sure most transversely mounted engines could be done without removal from the vehicle.

I think it can still be done…Remember once you remove the heads…that’s several inches of added clearance you just gained.

Good point, but I’m thinking more of what’s under and around the pan. I could be wrong.

Good instructive comments all, thanks.

My only experience with replacing piston rings was with a 20 year old 2 cycle motor for a Lawn Genie lawnmower that was steadily loosing power due to low compression. Replacing the piston rings in that engine was a snap. I’d be surprised if it took me more than 90 minutes, start, to finish. The new rigns cost about $25 total as I recall, for the complete set.

It worked great with the new rings, almost like new. Well, until the magneto developed a crack and promptly failed. But, hey, it worked great for a few months!

@GeorgeSanJose–Two stroke lawnmower engines are easy engines to replace the rings. I used to do a lot of mowing for people when I was in high school. We had a LawnBoy mower with a 2 stroke engine. The cylinder walls were tapered, soa ring compressor was not needed to put the piston back into the cylinder after replacing the rings. At the end of a season, I would buy a set of rings, a new needle and seat for the carburetor, new points and condenser, a complete gasket set and a new Champion J-8 spark plug. After removing the cylinder from the crankcase, I would pull out the piston, rough up the cylinder wall with some crocus paper, scrape the carbon off the piston and install the new rings, rebuild the carburetor, reassemble the engine, install the points and condenser, put in the spark plug and it was good to go for another season. I chickened out on my 4 stroke lawnmower. When the engine puffed oil smoke and lost power, I just installed a new short block. Not only would the valves have to be ground, but a ring compressor is needed to get the piston back into the cylinder.

Here’s one thing I’ve never figured out. How is it that a person can answer questions about automotive problems and provides their opinion, and at the same time doesn’t understand the basics of a re-ring job on an engine?


If deep knowledge of an issue was required, 90% of all commenters on all issues would be shut down…

Today, most of the time, the entire engine gets replaced with a factory-built replacement…Engines don’t wear out one part at a time…If the rings are shot, chances are the entire engine is shot…

More than likely, a worn-out engine sends the car to the shredder. The cost of replacing the engine (what about the transmission?) exceeds the value of the car…

@Caddyman–“More than likely, a worn-out engine sends the car to the shredder”. It’s almost like having a car repaired with a new engine is like repairing a refrigerator with a new compressor. It just isn’t done much any more. I remember when I was a kid, my dad had new rings and a valve job on his 1939 Chevrolet. The engine did not have to be removed from the car. This was in 1949. The same year the refrigerator quit. A repairman came out, removed the motor, had it rewound and was back the next day to put the refrigerator back in service. My dad never had a ring job on any car after the 1939 Chevrolet. When the car started using oil, it was traded. When the next refrigerator with a sealed unit quit because of the compressor, the refrigerator was replaced.

In the 40s, rings usually wore out between Forty and sixty thousand miles. They were the weak point of the engine. No one expected their engine to go a hundred thousand miles. When they say " They don’t build them like they used to " That is a very, very good thing.