Mar. 06, 2024
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.
Table of Contents
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
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
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.
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.
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.
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.
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.
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.
The main causes of a deteriorated seal come from faults within the seal itself and improper installation. Even though valves consist of high-strength rubber, they can break, crack or wear down. Seals could even be missing from a botched installation. Any of these faults in the seal will cause oil to reach the engine’s cylinders.
As valve stem seals begin to fail, carbon buildup forms, which also affects other engine components like the valve seat and guide — which is why quick repairs are critical.
In some cases, there still may be excellent compression. However, if high oil consumption is present, it will then cause higher operating temperatures that can lead to broken or cracked seals. Seal problems can also form from an improper clearance between the valve and valve guide. When it’s loose within the cylinder head, it can move laterally, wearing out the valve.
The best thing you and your crew can do is refer to your preventive maintenance schedule for each piece of equipment in your fleet and complete regular safety checks.
Daily or weekly inspections will help you find leaks and problems before they become more severe.
It’s also essential to invest in top-quality valve seal solutions that are free of defaults. Partnering with a company that guarantees seal products with no defaults places you ahead of the competition, giving you a competitive advantage.
Because many factors can indicate a bad valve stem seal, you’ll have to investigate and not always rely on the various signs. If you have the appropriate training and qualifications, go ahead and start your inspection. Otherwise, rely on the experts for guidance.
Open the hood to the engine and check the oil level of your machine using a dipstick. Is it significantly lower compared to other times after a similar amount of usage? You can also check to see if there is any excess clearance between the valve stem and guide. Leaks are an obvious sign the valve stem seal has issues — but these aren't always present, even when the seal is failing.
Start the engine and observe the exhaust. Is there a lot of smoke coming out of the pipe, and does it have a blue-gray tint? If so, the engine is burning leaked oil — which is why you may not see any leaks under the hood.
Listen for odd noises like rattling or tapping as the engine idles. Any unusual sounds can indicate problematic valves.
Check for engine and error lights that can indicate a problem. You can hook the machine up to a diagnostic reader to scan for different error codes. For example, valve seal and valve guide issues will read as specific codes, so reference the owner’s manual for assistance.
If worse comes to worst, you will need to disassemble the engine and inspect the valve stem seals and other components. Relying on the professionals for this step may be best to ensure more parts do not get damaged throughout the process. You or the expert should look for dented, cracked, broken or deteriorated valve seals.
Valve stem seals' replacement costs are affordable in the long run because new seals prevent more catastrophic engine damage.
If oil is leaking from your engine, you’ll want to find a temporary, stopgap solution until you identify the issue and make repairs. For example, you can use an oil stop-leak additive in the oil filler, just like you would with regular engine oil. The additive will give the valve seals a quick fix by causing them to expand, creating a rapid extension of life.
You can also add high-mileage oil with seal conditioners that can slow or stop oil leaks. This type of oil keeps the seals pliable to help prevent corrosion.
Once you make a short-term fix, it’s crucial to start on repairs or replacements right away. Prolonged valve failure can affect the entire engine and hydraulics system, costing you expensive repairs or replacements in the future.
Failed parts can also affect your workers' safety and well-being. Your machine may begin to operate hazardously with a jolt of power or faster/slower movements than usual.
Once you’ve taken the correct preventive measures, replace the leaking seals using the following steps:
1. Remove the seal cover.
2. Get rid of any buildup.
3. Place sealer on both sides, unless it’s rubber.
4. Position the new seals.
5. Place the cover back on.
6. Tighten bolts.
Fast valve stem seal replacements are just as essential as choosing a manufacturer that knows the vitality of a well-designed valve stem seal. Look for custom solutions that can fit your specific requirements if your machines are unique to your industry or operations.
You will want to invest in top-tier solutions that are free of defaults. For example, Global Elastomeric Products has an inventory of rubber seals that provide an elastomeric seal for your engines. We focus our valve seal portfolio on durable, temperature- and chemical-resistant solutions. We can also manufacture any customized rubber compound to fit your unique needs.
Our packer elements and valve seals include:
Arrow
Baker
Baker/Brown
Guiberson
Quality means everything when you’re trying to meet your oil or agricultural industry quotas, including valve seals. Your business needs to rely on elastomeric products that produce defect-free replacement parts just as much as you count on efficient employees on your rig. If you neglect quality, you can put your operations and workers at risk of breakdowns and injuries.
Functional valve stem seals are crucial in keeping your operations efficient. Whether you work in the agricultural, oil or another industry, your machines drive daily operations. If you’re experiencing seal leaks, deterioration or damage, Global Elastomeric Products has what you need.
We guarantee our standard and custom in-house seal designs will be free of defects. Our experts design, manufacture and distribute our valve seal product lines while keeping your specifications at the forefront of each customization. We can generate product designs and engineer seals for any oil field or agricultural application. Global Elastomeric Products is the solution to your leaking and damaged seals.
Reach out to us online with questions or for more information about our solutions. You can also request a free quote by calling us at 661-831-5380 to help you better understand our valve stem seal products.
On some applications, the valve stem seals are interchangeable between the intake and exhaust valves and will look exactly the same. On applications which use different seals on the intake and exhaust valves, due to needing higher temperature material on the exhaust side or different design, the seals will be bagged and labeled appropriately.
An installation tool is included in Fel-Pro valve stem seal (VS) sets. This tool is a thin plastic sleeve which is placed over the tip of each valve stem during installation. It protects the inner lip of the seal from damage by the lock grooves in the valve stem.
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Learn more about Fel-Pro quality gaskets that are specifically designed for the repair environment, find your car part, or find where to buy your auto part today.
The content contained in this article is for informational purposes only and should not be used in lieu of seeking professional advice from a certified technician or mechanic. We encourage you to consult with a certified technician or mechanic if you have specific questions or concerns relating to any of the topics covered herein. Under no circumstances will we be liable for any loss or damage caused by your reliance on any content.
Valve stem seals are a part of the valve system; these seals contribute to lubricating the valve so it can maintain the ratio of fuel and air mixture. This mixture further goes for combustion purposes and gives power to a vehicle. These valve stem seals are small parts, but they play a very important role in maintaining the engine’s sanity. The right amount of lubrication is needed, not more than that, and not less than that; the same confirms the valve stem seals. Bad valve stem seals lead to an overall malfunction in the engine. Let’s see how you can identify the seals that if they have gone bad.
Valve stem seals provide a leak of the oil to keep the valve system lubricated. When the lubrication is in a controlled manner, this helps the valve guide to slide without any harm. Too much oil and it causes carbon buildup; too less of oil, and it causes the stem and guide wear.
There are two kinds of seals: Positive and deflector. The positive kind attaches to the valve guide boss, and it functions there squeegee, wiping, and metering oil.
Deflector seals work as the name implies, they redirect the oil away from the valve stem. That is why these are also called the umbrella seals as they shield the valve guide from excess oil.
Now, let’s head on to recognizing bad stem seals-
If you encounter a white-blue smoke like thing when you start the engine, this is the sign that is easily noticeable. When you let the vehicle sit overnight or for a long amount of time, the residual oil coats the top of the head inside the valve cover. When you start the engine, the residual oil gets sucked down. The seal then takes this oil into the combustion chamber, and since it is the residual oil, it releases the white blue kind of smoke out.
This kind of smoke also generates when you keep the vehicle idle at the stop signs or anywhere. When the car sits idle, the throttle valve remains closed, and this results in high levels of vacuum at the intake manifold. This situation further attracts the oil in the heads that gathers around the stems.
When the driver accelerates, this oil gets sucked past the eroding seal, and there it goes to the valve guide and burns in the exhaust. This burning then releases the huge white-blue clouds; the process repeats after every acceleration at idling.
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Another stage when you can notice the steam going bad is during the off-throttle braking. When you descend a steep downgrade while keeping the accelerator pedal static, the high intake manifold vacuum generates. This makes the oil getting collected toward the front of the valve cover.
When you push the acceleration, the burned oil exits the tailpipe in much amount, and it becomes a matter of concern to get the things right.
How about excessive oil consumption? The oil consumption, more than needed, takes place when the stem seals go bad. This level of oil can be noted beforehand using a dipstick, and then after a ride, you can notice it again. If the oil level has gone down significantly, it is a sign. This happens because the oil also burns with the fuel in a significant amount.
If the valve seals are worn enough, you can notice the blue-white smoke always on startup. Though the smoke fades after the engine operates for longer, initially, the smoke always shows up. It happens because bad valve seals result in oil burning, and that may be irregular. Similarly, when the problem is with the piston rings and valve guides, the smoke never fades away even after the longer operation.
The valve stem seals are made from a variety of materials; they can be made of nylon, PTFE rubber, steel, and synthetic rubber. To determine the right kind of stem seals, you can always prefer some maintenance tips by your professional car repairer.
Sometimes these materials are combined into one to form a single and classy design. The synthetic rubber seals are the most used ones, and they are of three types: nitrile, polyacrylate, and Viton®. The quality of these seals depends on their heat resistance, and since Viton® is the best type of synthetic rubber seal, it is used widely.
The seal gets combined with a metal jacket, and as a result, it protects against both heat and abrasion. So while looking for a stem seals replacement, read the manual and buy the type of seal accordingly.
The replacement cost would charge you anywhere from $30 to $100 depending on the year and model of your car. But the problem is the labor cost and time. You would be needed to let your car be at the mechanic shop for 2 to 4 hours. The labor cost would charge you anywhere from $60 to $100 per hour, depending on your location or the city. This makes the total price between $150 and $500 on average.
For a seal replacement, it is best to take your car to a professional mechanic. As these seals are responsible for controlling the lubrication in the valve stem, these tiny parts play an essential role in there. Leaving the matter uncured only leads to worsening of your engine and seeing the symptoms more frequently. We hope you now understand the valve stem seals, how they work, and what the replacement cost is.
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FOUNDED IN 1993
China SBT Oil Seal is an international company integrating design, research and development, production and processing.
No. 68, Hua'an Street, Renze District, Xingtai City, Hebei Province, China
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Won many honorary certificates through a number of patented inventions
