We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Cylinder Liner?

By Lori Kilchermann
Updated May 23, 2024
Our promise to you
WikiMotors is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WikiMotors, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A cylinder liner is a device that is pressed into an engine block and houses the piston. It is much harder than the engine block and prevents the piston from wearing through the cylinder bore. Typically used in aluminum engine blocks and diesel engines, the cylinder liner is either pressed into position or held in place by the cylinder head. In large engines such as the engines found in diesel locomotives, the liner is part of an assembly containing a new piston, piston rings and a connecting rod and is changed as a complete unit during scheduled maintenance or repair.

In aluminum engine blocks, the block material is much too soft to house a piston. The friction of a piston moving up and down inside the alloy block would soon wear out, resulting in a loss of compression and severe oil consumption. The steel cylinder liner is pressed into the engine block and then the engine block is machined to assure that the cylinder head mating surface is smooth and flat. By machining the engine block to receive a steel liner, the engine is able to operate for many years without engine failure.

The flat surface resulting from the machining of the engine block assures a proper seal of the head gasket between the cylinder head and the engine block. An improperly sealed head gasket will result in over-heating of the engine, loss of power, and the potential to ruin the block and cylinder head. Great care must be taken when installing a cylinder liner into an aluminum engine block since the aluminum block will react to heat at a different rate than the steel cylinder liner. Improper fit at installation could result in a broken liner or a cracked engine block.

There are also instances when a cylinder liner can be used to repair a cast iron engine block that has suffered a catastrophic failure to a cylinder wall. Often, when an engine fails or "blows up," the cylinder wall takes the brunt of the trauma rendering it unrepairable by over-boring. In this instance, the block might be machined to receive a liner and then all of the cylinders could be over-bored to the same size, rendering the engine useful once again. For street driven vehicles, this is a viable option which typically offers the vehicle owner a significant savings over the cost of a replacement engine.

WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By Viktor13 — On Oct 24, 2011

I can understand the reservation about replacing a liner in a car, but in a train yard it's just the opposite. We replace liners all the time on a schedule, and it can greatly extend the life of the engine.

This makes sense for a train, though. The engine blocks are gigantic, so there's lots of "wiggle room" and strength is not an issue. Also, trains put on an incredible number of miles every year, so if the engine block was not designed for easy maintenance you'd have to be changing and rebuilding the whole engine block very frequently, and they are not easy to handle because of their size and weight.

People don't really keep cars that long these days, otherwise someone might have developed a similar setup for car engines. Nowadays if you did that the body would rust away and you'd just have a frame with an engine in it.

By bigjim — On Oct 23, 2011

While I agree that you can use a liner to replace a failed cylinder in an iron block, I have always hated to do it, and I wouldn't have one in my own car.

A big chunk of cast iron like that is a pretty strong thing, but I still would question the strength of it after the cylinder had a catastrophic failure, even with the new liner.

Also, you now have the parts in that one cylinder all new and mismatched from the rest of the moving parts in the head. That makes me very nervous.

Call me paranoid, but I would probably just swap it for a rebuilt engine unless I just plain couldn't afford it

By Veruca10 — On Oct 22, 2011

One of the many annoying things about working on a diesel engine is having to deal with the liners in the diesel cylinder head. I get why they are there, but I've always hated dealing with them during a rebuild.

That said, they do make the engine last a lot longer. You can get half a million miles out of a well-maintained diesel engine, and part of that is because they liners increase the lifespan of the cylinders quite a bit.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.