How to Check Valve Stem Seals

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How to Check Valve Stem Seals

Oct. 29, 2022

How to Check Valve Stem Seals


How to Check Valve Stem Seals

valve seals precisely control the amount of oil entering the valve stem system, making them critical components in maintaining your engine’s compression levels. Having a valve stem seal that works correctly within any of your applications can save you time and money by eliminating the need for lengthy engine repairs and replacements. But how do you check for bad valve seals, and what signs should you be aware of?

No one wants to face valve issues because they indicate a severe problem within your machine’s engine. Here is where Global Elastomeric Products comes into play. Learn how to find faulty seals and what you can do to avoid these issues.

Valve stem seals control oil consumption and lubricant in an engine by allowing a specific amount of oil inside the valve stem as it moves. A controlled amount of oil is crucial in maintaining adequate lubrication. Otherwise, too little oil can cause various components to wear as parts rub together. However, excess oil can result in carbon buildup, which can lead to many issues, such as:

Damaged valve seats
Degraded catalytic converters
Increased emissions
Less efficiency
More oil consumption Get more information


How to Check Valve Stem Seals

Essentially, valve stem seals prevent oil from entering the combustion chamber from the cylinder head. A damaged seal can cause engine oil flooding that will lead to engine failure.

Six ways to assess whether you have a faulty seal on your hands include:

1. Cold engine test
2. High levels of smoke
3. High oil consumption
4. Idling
5. Less acceleration power
6. Misfiring Get more information


How to Check Valve Stem Seals

1. Conducting a Cold Engine Test
One of the best ways to tell if you have a faulty valve seal is to conduct a cold engine test. After your machine hasn’t run for a while — even overnight — the seal is now cool. Once you start the engine, the seal will contract. Damaged seals will leave a small gap. Leftover oil will then settle at the top of the valve cover head.

When you start the engine, you may also see blue-tinted smoke appear from the exhaust. If this happens, it means the residual oil is passing down through the damaged seal and into the combustion chamber. The bluish smoke, which is burned oil, signifies that the engine needs a new seal, even if it clears after several minutes of running the engine.


2. Increased Smoke Levels
Depending on the machines and equipment you use, smoke is often a common form of exhaust. However, when you start seeing it last longer than usual or appear a different color, you know a faulty seal may be the cause. The excessive smoke may also come in more consistent waves as the engine runs for long periods. Be aware of specific machine movements that cause more smoke than usual.


3. More Oil Consumption
If you notice you’re going through more oil than usual, it can be another indication of a bad seal. When oil leaks or burns at higher rates, the seal no longer controls the oil flow. Burning oil increases emissions and can contaminate the catalyst. Unburned fuel in the exhaust skyrockets the converter’s operating temperatures, which can cause the converter to overheat and create a blocked exhaust.

Make sure to check the engine’s oil level with a dipstick, and refer to your oil log to see if the fluid levels differ. You can make this part of your regular maintenance schedule. While oil leaks are often a clear warning of faulty valve seals, they may not always be visible, so don’t rely on this as a guaranteed warning because the oil could be burning off.


4. Engine Idling
Pay attention to your machines if they ever idle. When the engine is at rest, high vacuum levels can cause the oil to build around the heads of the valve system while the valve is closed. If the seal is faulty, you may once again see blue-tinted smoke when the engine begins to run. That means the oil is getting pulled past the seal and into the valve guide. Make sure to shut the engine down and remove it from operation until you can get it repaired.


5. Compromised Acceleration Power
Depending on the engines you use in the oilfield and agricultural industries, testing the engine’s compression can also help determine if your valve stem seals are deteriorating. If the machine has a higher compression level, you have a valve seal issue and you'll need replacements. On the other hand, a lower level may designate a piston ring malfunction.


6. Engine Misfiring
An engine with broken seals can cause oil to build on the electrodes of the engine’s spark plugs. As a result, plug fouling can occur, which is an accumulation of carbon deposits that can cause engine misfires. As carbon buildup increases, so does compression, leading to engine damage from faulty detonation or even issues with pre-ignition.

Knowing these six signs of valve stem seal failure can help you mitigate the issue before problems like oil leaks and high compression levels begin. The sooner you notice different-colored smoke, an increase in oil usage, misfiring engine startups and idle noises, the faster you can make the necessary seal repairs. In return, your operations will remain efficient, productive and safe.Get more information


How to Check Valve Stem Seals

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