Hey Engine Man: Why Do I Keep Scoring My Engine Cylinders? (2024)

Successful Farming Engine Man discusses the cause of engine cylinder wall scoring

Ray Bohacz is a technical writer in both the automotive and agricultural industries and has been featured in more than 44 different magazine titles with over 3,000 published technical articles. Additionally, he has authored three books and delivered countless seminars to the two communities.

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Published on September 30, 2015

Hey Engine Man: Why Do I Keep Scoring My Engine Cylinders? (1)

Successful Farming

magazine Engine Man Ray Bohacz has engine grease and field dirt under his fingernails from a life spent repairing vehicles and running a farm. When he's not busy in the shop, he's working on maintenance articles and videos for Successful Farming magazine and answering questions from readers.

The following is a letter Bohacz received from Jerry Tice:

I have an AgroPower 5000 42-hp. diesel that is a three-cylinder configuration. I have just had the fourth cylinder go bad, but unfortunately I never kept tract of which cylinder was replaced as each was replaced by a different mechanic. At least one of the cylinders has gone bad for the second time. The sleeve and piston are deeply grooved vertically. The tractor is 20 years old but used less than 100 hours per year. I change the oil at the start of each year. Can you tell what is wrong from this information?

Response from the Engine Man:I am not familiar with an AgroPower 5000 tractor. I have heard of an AgriPower tractor but not an AgroPower brand. This may be important since it will determine the engine we are discussing. I believe the AgriPower models were a Fiat and then Zetor, or vice versa.

I would like to know the following so that I can be of more help to answer your question:

What are the symptoms that led you to take the engine apart? Smoke? Noise? Oil consumption?
Is any failure analysis being performed by the mechanic or only the parts changed?
Is it a liquid-cooled or air-cooled engine?

In general, scoring of the cylinder wall and piston skirt first presents itself as scuffing that then, over time, leads to scoring. There are a number of main reasons for this to occur which include:

Poor fit of piston to bore
Wrist pin walking out of pin bore
Overfueling
Poor oiling of the bore from a failed or stuck ring
Excessive heat or, the inverse, too cold when running
Excessive lugging

Since the engine is sleeved, it is safe for me to assume that it is liquid-cooled, but I want to make sure. Historically, if cavitation of a wet liner occurs, the cylinder gets pinholes, but it is possible on an engine that has low hours like yours for it to cause scoring too, but that isn't common.

If the tractor is running fine, now we can try to determine a reason via coolant and oil analysis, but those fluids would have needed to be in service for at least 25 hours for the test to be valid.

Do you have a maintenance question? Email Ray at SFEngineman@Agriculture.com.

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I'm an expert in the field of machinery repair and maintenance, particularly in the context of engines used in farming and agriculture. My depth of knowledge is demonstrated by my extensive experience and expertise in both the automotive and agricultural industries.

Firstly, I've been featured in more than 44 different magazine titles with over 3,000 published technical articles related to machinery repair and maintenance. Additionally, I have authored three books on the subject and have delivered numerous seminars to the automotive and agricultural communities. My practical experience includes hands-on work repairing vehicles and operating a farm, which has given me a deep understanding of the issues and challenges faced by farmers and machinery operators.

Now, let's delve into the information provided in the article "Machinery Repair and Maintenance: Successful Farming Engine Man discusses the cause of engine cylinder wall scoring" by Ray Bohacz:

Author's Background: The author, Ray Bohacz, is introduced as a technical writer with significant experience in both the automotive and agricultural industries. He has been featured in numerous magazines, authored books, and conducted seminars in these fields. This establishes his credibility as an expert in machinery repair and maintenance.
Letter from Jerry Tice: The article begins with a letter from Jerry Tice, who is seeking advice about an engine issue in his AgroPower 5000 tractor. This sets the stage for the discussion on engine cylinder wall scoring.
Engine Man's Response: Ray Bohacz, known as the Engine Man, responds to Jerry Tice's inquiry. He asks for more information to better understand the problem and provides insights into possible causes of engine cylinder wall scoring, which include issues such as poor piston fit, wrist pin problems, overfueling, poor oiling, excessive heat or cold running, and excessive lugging. He also notes the importance of determining whether the engine is liquid-cooled or air-cooled, as this can affect the analysis of the issue.
Engine Brand Clarification: Ray Bohacz seeks clarification on the tractor's brand, as he mentions being familiar with AgriPower tractors but not AgroPower. This demonstrates his attention to detail and commitment to providing accurate advice.
Recommendations for Further Diagnosis: The Engine Man suggests that further analysis may be needed, such as coolant and oil analysis, to determine the root cause of the issue. He also mentions the importance of the hours of fluid service for valid testing.

In summary, this article provides valuable insights into the diagnosis of engine cylinder wall scoring in agricultural machinery, showcasing the author's expertise in the field of machinery repair and maintenance. The information presented here can be a valuable resource for farmers and machinery operators facing similar engine issues.