How To Fix Blow By On A Diesel Engine

If you own a diesel engine, you might have encountered the issue of blow by. Blow by is a situation where the engine’s combustion gases escape past the piston rings and enter the crankcase. This can lead to a variety of problems, such as reduced engine performance, increased oil consumption, and increased emissions. In this article, we will discuss how to fix blow by on a diesel engine.

What Causes Blow By?

Blow by can be caused by a variety of factors. One common cause is worn or damaged piston rings. When the rings wear out, they can no longer seal the combustion gases, causing them to leak past and enter the crankcase. Another common cause is worn or damaged cylinder walls. If the walls are scratched or scored, they can no longer provide a smooth surface for the rings to seal against.

How to Diagnose Blow By

The first step in fixing blow by is diagnosing the problem. One way to do this is by performing a compression test. A compression test measures the pressure in each cylinder and can help identify cylinder-specific problems. Another way to diagnose blow by is by performing a leak-down test. A leak-down test measures the amount of air that escapes from each cylinder and can help identify the source of the problem.

How to Fix Blow By

Now that you have diagnosed the problem, it’s time to fix it. One way to fix blow by is by replacing the worn or damaged piston rings. This involves removing the engine’s pistons and replacing the rings. Another way to fix blow by is by honing or boring the cylinder walls. This involves removing a small amount of material from the walls to create a smooth surface for the rings to seal against.

Another option is to replace the entire engine. While this may seem like an extreme solution, it can be the most cost-effective in the long run. If your engine is old and worn out, replacing it with a new or rebuilt engine can save you money on repairs and maintenance.

FAQs

Q: Can blow by be fixed without replacing the engine?

A: Yes, blow by can be fixed without replacing the engine. The most common solutions include replacing the piston rings or honing/boring the cylinder walls.

Q: What are the symptoms of blow by?

A: Symptoms of blow by include increased oil consumption, reduced engine performance, and increased emissions.

Q: Can blow by cause engine damage?

A: Yes, blow by can cause engine damage. If left unchecked, blow by can lead to increased wear and tear on the engine and reduced engine life.

Conclusion

Blow by is a common problem in diesel engines, but it can be fixed. By diagnosing the problem and choosing the right solution, you can get your engine running smoothly again. Whether you choose to replace the piston rings, hone/bore the cylinder walls, or replace the entire engine, fixing blow by can save you money on repairs and maintenance in the long run.