Valve Stem Seals Guide: Definition, Types, Signs of Failure

Reading Time: 3 minutes

There are many kinds of seals in a vehicle’s engine. A valve stem seal is a small component that keeps the valve stem sufficiently lubricated so that the engine can run smoothly. A leaking valve stem seal can cause poor engine performance and negatively affect emissions. Let’s take a deeper look into valve stem seals, what causes them to fail, and when to replace them.

What Is a Valve Stem Seal?

The valve stem is located beneath the valve springs in the engine’s cylinder head. The valve stem seal regulates the amount of oil in the valve stem that goes into the valve guide. Insufficient lubrication can cause the valve stem and guide to wear out faster due to friction. Excessive lubrication can result in carbon buildup that damages the valve seat, increases vehicle emissions, and causes oil consumption. Valve stem seals are available in two designs:

The valve stem seal regulates the amount of oil in the valve stem that goes into the valve guide.

Deflector Seals

Deflector seals, also known as umbrella seals, deflect oil away from the valve stem to prevent excessive lubrication.

Positive Seals

Positive seals are attached to the valve guide boss, functioning like a squeegee that meters and wipes oil as it passes through the seals.

How Do Valve Stem Seals Work?

Internal combustion engines require the right amount of air and fuel to operate. A disruption in this mixture can cause potential damage to the system, as well as performance issues. The valve stem seal prevents oil from entering the engine’s combustion chamber, where it can cause severe damage to various components. It also prevents oil in the cylinder head from being contaminated by intake and exhaust gases.

The valve stem seal has an inside diameter that fits over the valve stem and an outside diameter that fits over the valve guide. They form a secure seal between the crankcase and combustion chamber, which prevents contamination and leaks.

How Are Valve Stem Seals Made?

Valve stem seals are made from a variety of materials, such as nylon, polytetrafluoroethylene (PTFE) rubber, steel, and synthetic rubber. These materials can be combined to create a single design. Valve stem seals usually have small springs that allow them to fit securely over the cylinder head.

What Causes Valve Stem Seals to Fail?

Several factors can cause valve stem seals to degrade over time. The following are some of the most common causes of valve stem seal failure:

• Valve stem seals can fail prematurely due to infrequent oil and filter changes
• Valve stem seals can fail due to improper installation

You might notice a lot of smoke coming from the tailpipe if you have a faulty valve stem seal.

What Are the Symptoms of a Failing Valve Stem Seal?

A broken valve stem seal will exhibit one or more symptoms. Here are some of the most common symptoms of valve stem failure:

Tailpipe Emits Bluish Smoke

Bluish smoke can be an indication that the valve stem seal has become loose, broken, or severely damaged. Leftover oil on the cylinder head can get sucked down through a faulty seal into the engine’s combustion chamber and produce bluish smoke when expelled. If you notice bluish smoke when you start up a cold engine or when you’re idling, you should inspect your system for signs of wear.

Increased Oil Consumption

Oil can leak into the combustion chamber if the valve stem seal is leaking, causing oil levels to drop faster than normal. Other failed parts can also lead to increased oil consumption, so make sure to check your entire system for damage.

Excessive Smoke

Leftover oil can collect at the front cover of the cylinder head and burn longer than usual when you push on the accelerator after coasting. When driving downhill, you might notice a lot of smoke coming from the tailpipe.

When Should You Replace a Bad Valve Stem Seal?

An average valve stem seal can last 150,000 miles or more, if you take good care of your vehicle. That means changing your ride’s oil every 5,000 to 7,000 miles to reduce friction between the engine’s parts. Proper installation can also extend your seal’s life and protect your engine.

How Much Does It Cost to Replace Valve Stem Seals?

Aftermarket valve stem seals cost anywhere between $1 to $80 depending on the brand and inclusions. Labor costs will be vastly different depending on how many cylinders and cylinder heads your vehicle has, as well as your location.

The post Valve Stem Seals Guide: Definition, Types, Signs of Failure appeared first on In The Garage with CarParts.com.

https://ift.tt/KgC1bk7 https://ift.tt/MShqXlp https://notes.io//Tzb4 https://ift.tt/c5Weq9w https://ift.tt/yJ5c0nv https://ift.tt/Dtf2ew8 https://ift.tt/1LC9iNo https://ift.tt/3TM12AY https://ift.tt/On1DRwB https://ift.tt/miRT3S4 https://ift.tt/KlwkyJu https://ift.tt/RcQ5ioq https://ift.tt/edJU3p8 https://ift.tt/6KRyhd1 https://notes.io//Tzxx https://ift.tt/NR0Dz31 https://ift.tt/1vExVwS https://ift.tt/l4bUIvN https://ift.tt/F6orYqS https://ift.tt/rTq7K8g https://ift.tt/RMizKv3 https://ift.tt/v1bgMOW https://ift.tt/KYSvURd https://ift.tt/l089WHU https://ift.tt/rq7tuYB https://ift.tt/NYFgDlV https://ift.tt/3gcwvKy https://notes.io//TzdJ https://ift.tt/prgXbvV https://ift.tt/pAOITZn https://ift.tt/6mVbWvO https://ift.tt/nXOBoNI https://ift.tt/0Y9IqUl https://ift.tt/xyzLZiq https://ift.tt/cueC3L6 https://ift.tt/OEkj4sH https://ift.tt/KSh7xH4 https://ift.tt/hZ072jb https://ift.tt/rvaChpL https://ift.tt/dw2lEZq https://ift.tt/zJyXNDE https://notes.io//Tzdn https://ift.tt/2PI6Qaq https://ift.tt/cb0OPGu https://ift.tt/dMCBeFc https://ift.tt/rUbFVIl https://ift.tt/j9HeS6P https://ift.tt/McYm3Ou https://ift.tt/QPO5rbT https://ift.tt/u2ajt1M https://ift.tt/DyTiUm8 https://ift.tt/3JqrZ4l https://ift.tt/zO9ajhq https://ift.tt/8E5fus6 https://ift.tt/w8oygUp https://notes.io//Tzdm https://ift.tt/hRCXnNV https://ift.tt/65p910Y https://ift.tt/dMCBeFc https://ift.tt/6QN0PkY https://ift.tt/Ozhdx3U https://ift.tt/0zvWRVl https://ift.tt/kWvBe3u https://ift.tt/OG4vSFu https://ift.tt/7rwkuqg https://ift.tt/FjhwiTy https://ift.tt/EBhCQVY https://ift.tt/zHBmKOv https://ift.tt/Tu3MRxn https://notes.io//TzxT https://ift.tt/bKQ2kXC https://ift.tt/gQM8tED https://ift.tt/3oxFUi1 https://ift.tt/8NIHOSf https://ift.tt/4fMT1dY https://ift.tt/IMBHdiA https://ift.tt/IyDLa1W https://ift.tt/ER78vmd https://ift.tt/Cuox5WX https://ift.tt/WRPiCow https://ift.tt/L0yXGvz https://ift.tt/x8v9SRa https://ift.tt/vqCciNU https://notes.io//TzhL https://ift.tt/yFpXJ0A https://ift.tt/q39D8je https://ift.tt/7r9s81y https://ift.tt/pWxM9uq https://ift.tt/e7AqXI4 https://ift.tt/aQed9Es https://ift.tt/mRS9fza https://ift.tt/2r1zBVX https://ift.tt/ex1sEqV https://ift.tt/VkesQ9a https://ift.tt/HnTfWeo https://notes.io//Tzdb https://ift.tt/bp8guD4 https://ift.tt/HL4O7Fs https://ift.tt/KpsSuGc https://ift.tt/xf7JiQb https://ift.tt/fsZCwzD https://ift.tt/uoWa1Aq https://ift.tt/xfEOY5C https://ift.tt/fAU8LPs https://ift.tt/QrBen0V https://ift.tt/nXUyZrJ https://ift.tt/16JK0og https://ift.tt/zDGIk8B https://ift.tt/JZCe5qc https://notes.io//TzsQ https://ift.tt/gWqbutE https://ift.tt/ymeORFQ https://ift.tt/Qrvs3dg https://ift.tt/KPtZ6aA https://ift.tt/XD36NdH https://ift.tt/N8QIX3b https://ift.tt/dvSLE0s https://ift.tt/eofDdV3 https://ift.tt/Va1fZF3 https://ift.tt/6FKrT2J https://ift.tt/atnBqWN https://ift.tt/E93btCB https://ift.tt/r9A7yQM https://notes.io//Tzdq https://ift.tt/ZB4eqKN https://ift.tt/UKubT6X https://ift.tt/mz5HEUe https://ift.tt/YhGXQdc https://ift.tt/vC0NwfI https://ift.tt/t6VjNqW https://ift.tt/6zerQUd https://ift.tt/PWyRduY https://ift.tt/5UoMKI8 https://ift.tt/i8fAR41 https://ift.tt/j8zaTeG https://ift.tt/WUz09jT https://ift.tt/6MaFo4K https://notes.io//Tzja https://ift.tt/s35Z6jM https://ift.tt/w6inNUF https://ift.tt/tSWVnHa https://ift.tt/ifrE4KJ https://ift.tt/A9cmaHC https://ift.tt/5UWNtxF https://ift.tt/gTHb12B https://ift.tt/efhqzMR https://ift.tt/AizHORs https://ift.tt/LyiqSMN https://ift.tt/H7DIK0U https://ift.tt/Fmdxr7j https://ift.tt/bPhRSiK https://notes.io//TzdH https://ift.tt/Nk08dJZ https://ift.tt/jhauCN7 https://ift.tt/BWVSlaN https://ift.tt/oTfeHYS https://ift.tt/A9sUqTy https://ift.tt/DjcxFy8 https://ift.tt/zT4vCYN https://ift.tt/ctRZxwa https://ift.tt/mpYzuxo https://ift.tt/u4lPOJA https://ift.tt/45RkUxC https://ift.tt/gpkdTjl https://notes.io//TzpE https://ift.tt/cdpl1CB https://ift.tt/yn7HqmB https://ift.tt/TKdAP19 https://ift.tt/pZ0XQIJ https://ift.tt/1598CaY https://ift.tt/qizgH7C https://ift.tt/WDtTev3 https://ift.tt/WX4c9HR https://ift.tt/17hq36y https://ift.tt/0l59piu https://ift.tt/AYI63yX https://ift.tt/rHeXsUx https://ift.tt/g9D1QFX https://notes.io//TzpN https://ift.tt/HREFXbA https://ift.tt/Ty5wF3i https://ift.tt/852lu7X https://ift.tt/BVXNcyC https://ift.tt/XQtGBbW https://ift.tt/ZBF09XW https://ift.tt/PgX4EU8 https://ift.tt/m26SBxb https://ift.tt/zZjJKAc https://ift.tt/o0RDpk2 https://ift.tt/0Qki12a https://ift.tt/btLDumP https://ift.tt/Nzgvcmq https://notes.io//Tzsb https://ift.tt/lkVmbDK https://ift.tt/U5kfX4K https://ift.tt/xoNHdyO https://ift.tt/WTnIE3z https://ift.tt/cGOuDeK https://ift.tt/TqVSW1N https://ift.tt/MjTywPZ https://ift.tt/oOcHytR https://ift.tt/uKlHFpO https://ift.tt/GXLlwiF https://ift.tt/BKicAC4 https://ift.tt/3tpjXuY https://ift.tt/h3a4ZLB https://notes.io//Tzat https://ift.tt/SGj8Igo https://ift.tt/zN7V6nm https://ift.tt/BNaQS2U https://ift.tt/c9post7 https://ift.tt/phNJQDa https://ift.tt/HuLIVUA https://ift.tt/GSI8DEL https://ift.tt/80oZis6 https://ift.tt/Wpux0Rs https://ift.tt/RyUvs3A https://ift.tt/racv5XE https://ift.tt/izBbYnS https://ift.tt/lacgt8P https://notes.io//TzpW https://ift.tt/MQxECZi https://ift.tt/FqwATra https://ift.tt/Cn8SOFY https://ift.tt/pZ0XQIJ https://ift.tt/GUPaB3K https://ift.tt/al7tJy4 https://ift.tt/EgNG10T https://ift.tt/wD7vZzh https://ift.tt/kmw7zSj https://ift.tt/zCvBO1f https://ift.tt/FUbxKau