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Why are cylinder liners rebored, not replaced, on passenger car engines?

Engines and lubricants are so good now that we have few opportunities for rebuilding engines. Shops that do this are fewer and fewer. Heavy duty diesels have liners because the trucks they are in go several million miles before being scrapped.

You’re assuming that everyone takes care of their vehicles properly. Many don’t. The ones that don’t are the ones that have premature engine/transmission failures.

True. Many new cars are specifying synthetics only for their engines. Also, I happen to notice fewer and fewer gross polluters like I used to see in the past. I would always hate getting behind a car billowing clouds of burned oil but really don’t see that nearly as much in recent years. Even over the past 50-10 years, I have seen a dramatic decrease in the number of these clunkers. I also suspect that with modern emissions equipment/sensors, a car in this condition might run so poorly or might not run at all that it cannot continue to be operated.

On the other hand, I know people who are terrible about checking/changing their oil. I would never want to buy one of these used. That being said, most modern engines will outlast the car it is in if proper care is taken.

On the other hand, I know people who are terrible about checking/changing their oil. I would never want to buy one of these used.

There’s an engineer who works for me and he leases a new car every other year…and during that 2 year lease he NEVER EVER does any type of maintenance…this includes oil changes. Unfortunately there are more of them out there.

That being said, most modern engines will outlast the car it is in if proper care is taken.

I agree with that.

Some leases include “free” scheduled maintenance during the lease which is probably smart if the dealer wants to get the car back in good condition to resell without tons of future warranty claims. I know people who have done the same thing. Just run the car for 2 years without anything being done like oil changes.

Correct me if I’m wrong, but didn’t the big block Caddy engines of the late 60s and 70s (472, 500) use removable cylinder liners?

The pics I’ve found show normal cylinders in the Caddy 472, no sign they had removable liners.

Correct me if I’m wrong, but didn’t the big block Caddy engines of the late 60s and 70s (472, 500) use removable cylinder liners?

No, they were a conventional block.

Today Engine failure is the LEAST LIKELY reason for a car to be sent to the shredder…Rebulding car engines in the field s loves labor lost… When the engine needs to be rebuilt the whole car needs to be rebuilt…It’s called buy a new car…

The last Mack I drove had 1.2 Million miles on it when I shut it down because it was running out of oil. The shop it was towed to refilled it with oil an completely missed the missing fuel pump bolt that was letting oil out of the engine and sent it out with another driver. It blew up in 100 miles.

This engine had never been rebuilt and ran strong pulling up to 143,000 lb. Who knows how long it might have lasted ?

It would be a ridiculous waste of money to build a car engine to those standards.

Manufacturers seem to have gotten good at various surface treatments that reduce cylinder wear. It’s rarely a problem when few cars go over 200,000 miles. An accident that would cost too much to repair probably sends most cars to the scrapper. Or an accumulation of deferred maintenance and minor repairs that add up to more than the car is worth.