Blow-by can harm an aging engine, but a certain amount is normal for most vehicles. Here is how to tell when there's too much blow-by in your diesel engine.

With a simple diesel engine compression test, it is possible to spot compression problems before they get worse. Here’s information on these tests and how to decide if it is time to perform one.

Is your engine underperforming? Our expert shares how a diesel engine compression test could provide the diagnosis.

Under rare circumstances, diesel engines can experience a phenomenon called runaway, where the engine uncontrollably exceed normal operating speeds.

If your car is getting older or you feel like you may be losing some engine power, a compression tester can help sort out the problem.

Diesel performance—power, if you will—is all about how a compression-ignition engine is fueled. A diesel will make great torque with a richer (more volume) fuel supply.