Finding the right best emission pcv valve breather grommets is about matching the hole size in your valve cover to the outer diameter of the grommet. If the fit is loose, the seal may be compromised. If it’s too tight, you might crack the cover or struggle to get the valve seated. The best choice is one that matches your specific valve cover material and hole size perfectly.
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1. Spectre Performance 5339 PCV Breather Grommet
Best for: Standard 1-1/4 inch filler-breather holes.
This grommet is designed to fit any valve cover with a 1-1/4 inch hole. It serves as an OEM replacement to keep your breather system sealed and working as intended.
Owning this means you have a simple, direct-fit part for most common engine setups. Because it follows OE specifications, it’s meant to drop right in without extra modification.
| Feature | Trade-off |
|---|---|
| 1-1/4 inch design | Requires specific hole size |
| OE replacement style | Not for custom hole diameters |
2. Dorman 42062 PCV Valve Mounting Grommet
Best for: Replacing worn-out factory grommets.
This part restores the seal on your PCV valve when the original rubber has failed or cracked. It’s built to match the exact fit and function of the part that came on your vehicle.
You can rely on this if you’re doing a standard repair on a supported engine. It’s backed by a century of automotive experience, so you’re using a part designed to be a reliable replacement.
Who it fits This is for owners doing a direct repair on a vehicle listed in the garage tool. It suits those who want to restore the original factory seal.
Who should pass Avoid this if you have aftermarket valve covers with non-standard hole sizes. It won’t work if your engine doesn’t match the specific vehicle fitment.
3. Moroso PCV Grommet
Best for: Aftermarket sheet metal or cast aluminum valve covers.
This grommet features an integrated baffle to help manage oil inside the valve cover. It’s designed specifically for holes with a 1.220-inch diameter.
Using this is ideal if you have a street performance engine with aftermarket covers. The baffle design helps keep oil from splashing into the PCV valve, which is a common issue with high-performance setups.
What goes smoothly:
- Fits popular GM PCV valves.
- Includes a built-in baffle for oil control.
- Designed for aftermarket valve covers.
What you have to accept:
- Requires a 1.220-inch hole, not a standard 1-1/4 inch one.
4. Spectre Performance 5333 PCV Breather Grommet
Best for: Eliminating oil splash in custom builds.
This grommet is designed to fit the standard filler-breather hole found on many covers. It’s built to prevent oil from splashing into your breather system.
You get a lifetime warranty with this part, which adds long-term protection for your build.
| Feature | Trade-off |
|---|---|
| Integrated splash control | Slightly more complex than a basic seal |
| Lifetime warranty | Only covers manufacturer defects |
5. Beck/Arnley 039-6428 PCV Valve Grommet
Best for: Import vehicle engine repairs.
This grommet is made of durable rubber material. It’s application-specific, ensuring it matches the OE form and fit of your import engine.
Snapshot:
- Matches OE form and function.
- Durable rubber material.
- Designed for harsh conditions.
- Application-specific sizing.
- Simple, direct installation.
6. Dorman 42049 PCV Valve Mounting Grommet
Best for: Specific vehicle mounting requirements.
This is another direct replacement option from Dorman that matches the fit and function of the original part. It’s constructed from quality materials to ensure a long service life.
Like other Dorman parts, you should use the garage tool to confirm it fits your make and model.
Who it fits This fits drivers who need a replacement that matches the original factory specifications. It’s for those who prefer to keep their engine components as close to stock as possible.
Who should pass Don’t buy this if your vehicle isn’t listed in the compatibility tool. It isn’t a universal part and won’t fit if the dimensions don’t align.
7. Dorman 42055 PCV Valve Mounting Grommet
Best for: Standard valve cover restoration.
This grommet is designed to restore full functionality to your PCV system. It’s a direct replacement part made to handle the heat and oil exposure of a standard engine.
It’s a low-effort repair that keeps your PCV system operating at its best.
What goes smoothly:
- Direct fitment for specified vehicles.
- Durable, heat-resistant construction.
- Restores original vacuum seal.
What you have to accept:
- Must confirm vehicle fitment before purchase.
8. Dorman 42344 PCV Valve Mounting Grommet
Best for: Heavy-duty engine applications.
This grommet is built for reliability in demanding engine environments. It matches the original part’s design to ensure your PCV valve stays secure and sealed.
| Feature | Trade-off |
|---|---|
| Heavy-duty construction | Slightly stiffer material than basic versions |
| Direct replacement | Requires specific vehicle match |
The remaining options include the SBC BBC SBF Valve for standard holes, the (8-pack) Calvana 5339 for bulk needs, and the I.D. 3/4″ Aluminum Valve Covers for smaller port requirements.
The Decision Filter
You must first measure the diameter of the hole in your valve cover. If you guess the size, the grommet will likely leak or fall out. Most people miss this: the material of your valve cover (steel versus aluminum) often changes the required grommet wall thickness. If you have an aftermarket cover, check the manufacturer’s spec sheet for the hole size. If you have a stock engine, use the garage tool to find the exact part number. Don’t assume all filler-breather holes are identical.
The Quick Checklist
- Is the hole in your valve cover the correct size for this grommet?
- Does your vehicle require a specific manufacturer-approved part number?
- Are you using an aftermarket aluminum cover instead of steel?
- Does your PCV valve require a baffle to stop oil splash?
- Will you be replacing all grommets on the cover at once?
- Do you know the exact model year and engine trim level?
Three Regrets Worth Avoiding
Regret #1: Buying a universal size without measuring your hole first. Many covers look the same but vary by fractions of an inch, leading to a loose fit. Always use calipers to measure the hole diameter before ordering.
Regret #2: Ignoring the need for a baffle on high-performance engines. Oil may enter the breather system if you choose a flat grommet instead of one with an integrated baffle. Check your valve cover clearance and opt for a baffled version if oil splash is a risk.
Regret #3: Failing to check the material compatibility of the grommet. Rubber must be designed to handle the specific heat and oil chemistry of your engine type. Use parts meant for your specific application to ensure longevity, as described by the Environmental Protection Agency regarding engine maintenance.
If You Want This, Look for That
| If you want… | Look for | Avoid |
|---|---|---|
| Stock replacement | OE part number | Generic universal parts |
| Oil splash control | Integrated baffle | Flat, open grommets |
| Custom fitment | Caliper measurements | Guessing the hole size |
| Heavy duty use | High-temp rubber | Standard rubber |
Match your valve cover hole size to the grommet outer diameter first. If you have two parts that fit, choose the one with the material rating that best matches your engine’s heat output. If you’re still unsure, verify your engine’s original part number using your VIN.
Related guides
Frequently Asked Questions
Can I use a silicone grommet instead of rubber?
You can use silicone if the manufacturer specifies it for your engine, but standard rubber is more common for factory applications. Always check your engine manual or the part listing requirements.
What happens if the PCV valve is too loose?
A loose PCV valve will allow unmetered air into your engine, which can cause a rough idle or poor fuel economy. It also creates an entry point for dirt and moisture to enter your crankcase. If the valve isn’t snug, it can vibrate out of the hole entirely under heavy engine load.
How often should I replace these?
Grommets should be inspected every time you perform an oil change or service the PCV system. Replace them whenever they show signs of cracking or when they no longer hold the valve firmly in place.
Final Thoughts
Before you finalize your purchase, double-check your valve cover’s specific measurements to ensure a snug, leak-free fit. Don’t settle for a loose seal that could cause messy oil buildup later on. Once you’ve verified the sizing, you’ll be ready to install your new parts and get your engine running smoothly again.