5 Piston Ring Failure Symptoms You Must Never Ignore

Published on 06/07/2022

5 piston ring failure symptoms you must never ignore

Diesel engines excel at pulling large loads over long distances. However, these heavy loads and long distances will take a toll on the vehicle and its engine. Over time, regular use wears the engine’s parts out, from spark plugs to piston rings.

Piston ring failure symptoms are similar in severity to overheating engine symptoms. The symptoms are noticeable and easily fixed before they permanently damage your engine. It’s essential to learn why your diesel truck is overheating or shuddering so you can correct the problem. 

Damaged and worn piston rings cause many of the problems your engine is probably experiencing. Once you know what you’re looking for, the symptoms are easy to spot.

What Is A Piston Ring?

Before discussing piston ring failure symptoms, we must first examine what and where piston rings are. Piston rings—or oil control rings—are small, inexpensive parts buried deep within the engine. Piston rings are attached to the pistons and pressurize the combustion cylinder.

The combustion cylinder is where air and fuel mix and ignite, turning the crankshaft with the resulting explosion. Turning the crankshaft causes more cylinders to fill with the fuel-air mixture and ignite it. This motion produces the power necessary to turn the engine and pull the vehicle and whatever load is attached.

Piston rings are integral to the entire process. Without a tight seal, the cylinder cannot pressurize, and the engine will lose its effectiveness. Engine wear or misuse will damage piston rings heavily over time.

Piston Ring Failure Symptoms

Symptoms of bad piston rings are similar to the symptoms of worn or damaged valve seals. Our trained technicians will be able to help, so make sure you bring your vehicle to us when you notice some of these symptoms. Catching symptoms in the early stages will save your truck’s engine and save you from a hefty bill.

Discolored or excessive exhaust

This symptom is readily apparent. When you run your vehicle, your engine puts out exhaust naturally, and it should always be a thin white. Bad piston rings will cause the color to change or deepen dramatically.

When the piston ring fails or becomes too worn to form a seal, the exhaust turns to a thick, dark gray, or bluish color. You might also smell burning oil.

As a piston ring fails, the seals break around the piston where combustion happens, eroding the barrier between the fuel-air mixture and the oil. The intruding engine oil offsets the precise fuel and air combination.

Once the spark plug ignites the mixture, the leaking oil ignites with the fuel and air, causing a dirty burn. The dirty burn causes a foul odor and discolored smoke.

Oil leaks or profuse oil consumption

Some oil consumption is natural in engines, but only when the oil needs to be changed.

Often, engines will start burning oil when it gets dirty or overworked. Still, no oil should be burning during the standard 3,000 to 5,000 miles between oil change services.

When you check your oil levels and see they are low well before scheduled service, it’s a sign that your engine is burning oil excessively or leaking oil somewhere. If you need to add excessive oil constantly before the scheduled service, your engine is burning or leaking oil.

The worn piston rings result in oil leaving the engine case and mixing into the fuel. This breach releases oil out of the engine that usually stays inside. If you notice drops of oil on the ground where your car was parked, consult a mechanic to check on your piston rings.

Declining engine performance

Poor engine performance is likely the worst of the piston ring failure symptoms. A decline in engine performance is easily noticeable because your vehicle doesn’t run as it should. It stutters, shudders, or even stalls out at times.

An engine that doesn’t perform won’t easily haul large loads. You don’t want to leave the engine in this state for too long. Leaving it like this will result in it breaking down.

If your engine is running this poorly, don’t hesitate to bring it in for an inspection! We can help you fix the problem before it breaks down completely.

Low acceleration

Technically, this symptom is a part of declining engine performance. However, the engine will often start losing acceleration before it begins to shudder or stutter. With a loss of acceleration, you might notice difficulty getting your car to smoothly and quickly accelerate to higher speeds.

Also, a vehicle with poor acceleration will struggle to pull itself up hills. Luckily, this issue does not cause long-term damage and has an easy fix. Changing the piston rings will immediately restore the standard acceleration rate.

Oil in the intake manifold

Inside your vehicle’s engine bay is a small filter where the intake pulls in air. This air mixes with the fuel in the combustion cylinder and is partially responsible for turning the engine. The fuel won’t ignite without air, and the engine won’t turn over.

When combustion happens around failed piston rings, it sometimes forces oil back into the intake manifold. This process is known as “blow-by.” You will identify blow-by with an oily film in the intake or oil drops on the air filter.

If it sounds serious, it’s because it is serious. Oil does not belong in the intake manifold, and it’s hazardous when it shows up here. Any static shock can ignite the oil, seriously damaging your engine or harming you.

Call Us To Fix Your Piston Ring Failure

Piston ring failure symptoms are straightforward for a trained technician to spot, and now you can spot them, too! Diagnosis, however, is just the first step. Fixing the problem is critical.

You need proper fleet maintenance to minimize wear and tear on your engines and to fix piston ring damage. Proper maintenance is the difference between a thriving and a dying business. Call All Bay Diesel at (925) 522-1780 for fleet maintenance services in Berkeley, CA.

Call Now: (925) 522-1780