Thinking of a way to reduce your vehicle emissions? Replacing your old valve stem seal just might do the trick. This seal ensures that your valve train and combustion chamber are properly lubricated for long-term engine performance and service life. It also prevents too much oil flow, which may lead to overheating. If you are looking for a valve stem seal replacement, here are the things you have to check out before buying:
- Umbrella-type or deflector-type: If you have a used auto with a pushrod engine, then this type of seal is what you might be looking for. Often paired with an O-ring, it is an easy-to-install component that works by deflecting the oil from the valve stem.
- Positive-type: Used in modern automobiles, positive-type seals provide a higher level of oil control compared to umbrella-type seals. Its design provides a tighter coverage, which reduces not just oil leaks, but also unwanted emissions. If your ride has an OHC engine, this is probably the seal design you should look for.
Valve stem seals can be made of different materials. Every material is not compatible with every vehicle-so before purchasing anything, make sure you know what your original seal is made of.
- Nitrile: This material is commonly used in low-end seals because of its cheap price and easy accessibility. Nitrile-based seals can be found in vintage vehicles and supercars.
- Polyacrylate: Similar to nitrile, polyacrylate is also common in umbrella-type seals, but it is a little more expensive and durable than nitrile-crafted seals. Seals made of polyacrylate are used in vehicles designed for everyday city or highway driving. Older engines such as the Chevy V8 also use seals made of this component.
- Fluouroelastomer (Viton): Viton possesses superior oil and heat resistance, making Viton-crafted seals perfect for race cars, off-road trucks, and other vehicles involved in heavy-duty applications. The downside: Viton seals can be really pricey.
- Silicone: One of the high-grade materials, silicone costs four to five times more than nitrile-based seals. Though it's not as tough as fluouroelastomer, this material handles higher temperature levels making it more powerful compared to nitrile and polyacrylate.
- Teflon: The toughest of them all, Teflon-crafted seals may cost 20 times more than nitrile-based products, but it is worth it-its performance against heat and wear is unmatched by other materials, even Viton. It provides maximum oil flow control. Used in positive seals, Teflon-made seals are common in high-performance automobiles. Apart from its steep price, another downside of using Teflon-made seals is compatibility. Not all valve stems are designed to handle this type of material.