Understanding the Role of a Catch Can in Your Engine

Before diving into the mounting process, it’s essential to understand what a catch can does and why it matters for your vehicle — especially if you live in a region with varying humidity and temperature. A catch can (or oil catch can) is an aftermarket device installed in the positive crankcase ventilation (PCV) system. Its primary role is to capture oil vapors, fuel condensation, and moisture that normally recirculate back into the intake manifold. By doing so, it prevents carbon deposits from building up on valves, intake runners, and turbocharger components. In Nashville’s humid climate, moisture accumulation in the crankcase is more pronounced, making a properly mounted catch can even more valuable for protecting engine longevity and maintaining performance.

When your catch can is mounted and secured correctly, it operates efficiently under all conditions — from the stop-and-go traffic on I-440 to the hot summer days when underhood temperatures soar. A poorly mounted can that vibrates loose or leaks not only fails to do its job but can also create hazards like hose chafing or oil spills in your engine bay.

Tools and Materials Needed

Having the right gear before you start saves time and ensures a professional result. The following list covers the essentials for mounting a catch can in a Nashville home garage setting.

  • Catch can kit with pre-drilled brackets or universal mounts
  • Wrench set (metric and standard, depending on your vehicle)
  • Screwdriver set (flathead and Phillips)
  • Mounting brackets or straps – heavy-duty metal or nylon
  • Drill and drill bits (cobalt or titanium for metal surfaces)
  • Hose clamps – worm-gear or spring-type, sized to match your fittings
  • Hoses and fittings – silicone or reinforced rubber, rated for oil and heat
  • Zip ties or P-clips for hose routing
  • Thread-locking compound (medium strength) for bolts
  • Protective gloves and eyewear
  • Shop rags and brake cleaner for surface prep

If you’re working in a Nashville garage during the humid months, consider using a dehumidifier in your workspace. Moisture can affect the grip of tape or the corrosion resistance of exposed metal brackets. For advanced installations, a torque wrench ensures brackets are fastened to manufacturer specs without overtightening.

Choosing the Right Mounting Location

Location selection is the most critical decision in the entire process. The catch can must be accessible for periodic emptying and inspection, yet secure enough to stay put under all driving conditions. Common locations include the inner fender well, the firewall, or a bolt-on strut tower bar. Here’s how to evaluate each option.

Inner Fender Well

The inner fender is a popular choice for many vehicles because it offers a flat, relatively cool surface away from direct engine heat. However, be mindful of wheel well clearance and splash exposure. In Nashville’s rainy seasons, the fender area can get wet; choose a location where the catch can and its fittings remain dry. If you install here, use stainless steel hardware and apply anti-seize compound to threads.

Firewall Mount

Mounting to the firewall puts the catch can close to the engine’s PCV system, reducing hose length. The firewall is robust and absorbs vibration better than sheet metal. However, it may require careful routing to avoid interference with the brake booster, heater hoses, or wiring harnesses. Before drilling, check behind the firewall for any components that might be punctured (e.g., AC lines, wiring). Use a grommet if running hoses through metal openings.

Strut Tower Bar or Radiator Core Support

For a show-quality install, bracket adapters allow you to mount the catch can on a strut tower bar or the radiator core support. These locations offer easy access and visual appeal. The trade-off is exposure to engine heat and potential vibration at the core support. Ensure the bracket is thick enough (at least 3 mm) to resist flexing.

Preparing the Mounting Surface

Once you’ve chosen the location, preparation determines how well the mount holds. A clean, bare metal surface provides the best grip. Use brake cleaner or isopropyl alcohol on a lint-free rag to remove oil, grease, and wax. If the area is painted, consider lightly sanding the paint down to bare metal where the bracket sits – this prevents the paint from chipping or peeling under the bolt head. For areas prone to corrosion (common in Nashville’s humidity), apply a thin layer of primer or sealant after drilling to protect exposed edges.

Mounting the Catch Can

With the surface prepared, you can proceed to attach the catch can securely. Follow these steps for a reliable installation.

Step 1: Attach Brackets to the Can

Most catch can kits include two-piece metal straps that wrap around the can body. If your kit uses separate bracket mounts, fasten them using the provided hardware. Use thread-locking compound on any bolts that connect the bracket to the can. Tighten to hand-tight plus a quarter turn – avoid crushing the can body.

Step 2: Position and Mark the Mounting Holes

Hold the assembly against the chosen surface and use a marker to outline the bracket holes. Ensure the can is level and oriented so that inlet/outlet ports point in the direction of hose routing. If using a universal strap-type bracket, you may need to drill a single large hole for a stud.

Step 3: Drill Pilot Holes

Start with a small pilot bit (1/8″ or 3 mm) to prevent the larger bit from walking. Drill slowly and use cutting oil on metal surfaces to keep the bit cool. For the final holes, match the drill size to the bolt or screw diameter. If mounting to thin sheet metal, consider using a backing plate or rivnuts to distribute load.

Step 4: Secure the Bracket

Insert the bolts from the backside if possible, or use self-tapping screws for lighter cans. Tighten in a cross pattern to even out stress. Apply thread-locking compound to the bolts – this is vital in a climate where temperature swings can cause fasteners to loosen. Finally, torque to manufacturer specs; for typical M6 bolts, 8–10 ft-lb is adequate for sheet metal.

Step 5: Test for Stability

Grasp the catch can and try to move it in all directions. There should be zero play. If you feel any wiggle, add an extra brace or use a larger fastener. A loose catch can will vibrate and eventually damage hoses or its own structure.

Connecting Hoses and Securing Fittings

Proper hose routing is as important as the mounting itself. The hoses must allow oil-laden vapors to flow freely while resisting heat and abrasion. Use the supplied hoses or upgrade to silicone hose with internal wire reinforcement for flexibility in Nashville’s temperature range.

Inlet and Outlet Orientation

Most catch cans have an internal baffle that requires flow in one direction – typically the inlet (from the engine) enters at the top or side, and the outlet (to the intake) exits at the opposite side. Confirm the manufacturer’s arrows. Connect the hose from the PCV valve or valve cover port to the inlet. Connect the outlet hose to the intake manifold port.

Securing the Hoses

Slide hose clamps over each hose end before pushing onto the barbed fittings. Push the hose fully onto the barb – at least 1 inch – then tighten the clamp just enough to compress the hose without cutting into it. Avoid overtightening; it’s better to recheck after a heat cycle. Zip tie the hoses to existing harnesses or rigid lines every 6–8 inches to prevent sagging and contact with hot surfaces. Route hoses away from exhaust manifolds, turbochargers, and sharp edges. If a hose must cross a sharp metal edge, use a split loom or spiral wrap as chafe guard.

Final Checks and Maintenance Tips

After all connections are made, start the engine and let it idle for a few minutes. Inspect the catch can for any rattles or vibrations. Check all hose clamps for leaks by feeling around the fittings – you shouldn’t feel any air or see oil. A quick test drive over bumpy Nashville streets will confirm that the mount holds under real-world conditions.

Regular Inspection Schedule

For optimal protection, empty the catch can every 1,000 miles or whenever you notice it’s half full. In Nashville’s humid months (May–October), condensation can increase the collected liquid volume, so check more frequently. Note the color and consistency of the liquid: a milky appearance indicates water contamination, meaning your catch can is doing its job. If you see pure oil, you may have excessive blow-by and should consult a mechanic.

Seasonal Adjustments

During winter, the PCV system works harder due to rich fuel mixtures and cold starts. Ensure your catch can is mounted low enough to drain easily but high enough to avoid road splash. In summer, underhood heat can soften nylon zip ties; replace metal clamps if you notice sagging. Every season, re-tighten the mounting bolts and hose clamps – temperature cycles can loosen them gradually.

Common Mistakes and How to Avoid Them

Even experienced installers can miss critical details. Here are the most frequent errors seen in Nashville garages.

  • Mounting too close to the exhaust – Engine heat will degrade the can and hoses quickly. Maintain at least 4 inches of clearance from exhaust components.
  • Using undersized hoses – Match the hose inner diameter to the PCV port. Restrictive hoses can cause crankcase pressure buildup.
  • Ignoring hose memory – Rubber hoses tend to take a set after bending. Use a hose forming tool or gently heat with a heat gun to shape them before final clamping.
  • Skipping the drain valve – If your catch can has a petcock drain, face it downward and accessible. Some installers mount the can upside down, blocking drainage.
  • Not using lock washers – Standard flat washers can loosen over time. Use split lock washers or serrated flanges under every bolt.

Nashville-Specific Considerations

Nashville’s climate of humid summers and mild, occasionally freezing winters creates unique conditions for catch can operation. High humidity increases moisture content in crankcase vapors, which can lead to sludge formation if the catch can is undersized or improperly drained. Consider a catch can with a larger capacity (at least 500 ml) if you drive a turbocharged vehicle. Additionally, Nashville’s urban stop-and-go traffic places greater demand on the PCV system; the catch can will fill faster than on highway cruises. Mount the can in a location where you can easily check the sight window – the inner fender may be too hidden for quick visual inspections. Many local enthusiasts prefer a firewall or strut tower mount for easy access at car meets or during weekend maintenance.

For more insights on engine protection, you can read this comprehensive guide on how catch cans work. If you’re working in a space-limited garage, consult this article on organizing your garage for engine work. Finally, check out the Nashville Car Culture Facebook group for local tips on PCV system modifications.

Conclusion

Properly mounting and securing a catch can in your Nashville garage is a straightforward process that pays off in engine cleanliness and performance. By taking the time to select the right location, prepare the surface thoroughly, and secure every connection with care, you’ll create an installation that stands up to Tennessee’s heat, humidity, and road conditions. Regular maintenance – especially seasonal checks – ensures your catch can continues to protect your engine for thousands of miles. Whether you’re a weekend warrior or a seasoned mechanic, these steps will help you get the job done right the first time.