Fixing 2020 Mustang Oil Consumption and Intake Manifold Upgrades

How to Fix Intake Manifold Replacement

For 2020 Ford Mustang owners, addressing intake manifold issues often centers on performance upgrades or resolving oil consumption linked to the PCV system, rather than a widespread failure of the stock part. The factory plastic intake manifold is robust, but owners seeking more power or dealing with specific oil issues look to aftermarket solutions. The data from owner discussions reveals a clear focus on upgrading for performance or modifying related components to solve oil ingestion. As one owner advised regarding upgrades, "First tip: it’s not worth it, the gen 3 manifold is pretty much on par with the boss 302 for airflow. Second tip: get a JLT intake and a tune from Lund and don’t waste your time on a manifold." This highlights the nuanced decision-making involved.

Symptoms

You might not experience classic "failure" symptoms with the stock intake manifold on a 2020 Mustang. Instead, symptoms are often related to the pursuit of more power or unintended side effects of the engine's design. A common thread among owners is unexplained oil consumption. This isn't typically a manifold leak, but oil being pulled through the Positive Crankcase Ventilation (PCV) system under certain driving conditions.

The primary symptom prompting manifold-related work is simply a desire for increased horsepower and torque, especially in the mid-to-high RPM range. Owners compare aftermarket options like the Boss 302 or GT350 manifolds to the stock Gen 3 unit, seeking that performance edge. Another symptom can be unusual noises that owners associate with intake or blow-off valves, particularly after installing aftermarket cold air intakes without proper tuning or components.

Lastly, in more severe cases of modification or if a vacuum leak were to develop, you could experience drivability issues like a rough idle, hesitation, or clutch shudder—the latter being more common in manual transmission models where engine load and vacuum signals are critical for smooth operation. However, the predominant driver for touching the intake manifold on this model year is performance enhancement, not repair.

Most Likely Cause

Based on extensive owner reports, the most likely cause for intake manifold-related attention on the 2020 Ford Mustang is not a fault, but a design characteristic of the PCV system that leads to oil consumption. The factory plastic valve covers house the PCV intake port in a location that can allow oil to be sucked into the intake manifold under hard acceleration or braking.

As owner SLNTGT explained: "The OEM plastic valve covers have the intake port for the PCV at the back end so under hard braking and acceleration you’ll suck some oil through." This ingested oil can foul intake valves, contribute to carbon buildup, and lead to a gradual loss of oil level that puzzles owners. While the intake manifold itself is the conduit, the root cause is the location of the PCV port. This issue prompts owners to consider solutions that involve the intake tract, such as installing an oil catch can or upgrading to valve covers with a better-designed baffle system.

How to Diagnose

Diagnosing whether your intake manifold or its associated systems need attention involves a few clear steps. First, monitor your oil consumption. Check the dipstick at every fuel fill-up. If you're consistently losing oil (more than 1 quart per 3,000 miles) without visible leaks on your garage floor, oil ingestion through the PCV is a prime suspect.

Next, perform a visual inspection. With the engine cool, remove the engine cover and inspect the intake manifold, its mounting points, and all attached hoses, particularly the PCV hose that runs from the valve cover to the intake. Look for any signs of oil residue or wetness at the connections. A significant amount of fresh oil in the intake tube or throttle body is a strong indicator. You can also use a smoke machine, a professional-grade tool, to check for intake vacuum leaks. Introducing smoke into the intake system with the engine off will reveal any leaks as smoke escapes from seals or cracks.

For performance-related diagnosis, the tool is a dynamometer. If you're considering a manifold swap to solve a perceived lack of power, a dyno run will show you exactly where your power band is and if an aftermarket manifold would actually benefit your setup. As one owner suggested, the Gen 3 manifold is very capable, so verifying a need is crucial before undertaking the swap.

Step-by-Step Fix

The fix depends on your goal: addressing oil consumption or upgrading for performance.

For Oil Consumption via PCV:

1. Install an Oil Catch Can: This is the most common and effective first step. It intercepts oil vapor from the PCV system before it reaches the intake manifold. Purchase a kit designed for the 2020 Mustang's Coyote engine.
2. Disconnect the PCV Hose: Locate the PCV hose running from the driver's side valve cover to the intake tube. Carefully disconnect it at both ends.
3. Mount the Catch Can: Install the catch can bracket in a suitable location in the engine bay, often near the firewall or strut tower.
4. Plumb the New Lines: Connect the provided hoses. Typically, one hose runs from the valve cover port to the "in" side of the catch can, and another runs from the "out" side of the catch can to the intake tube.
5. Secure and Check: Ensure all connections are tight with proper clamps. Start the engine and check for any leaks. Empty the catch can periodically as per the manufacturer's instructions.

For a Performance Manifold Swap:

1. Gather Parts and Tune: Secure the new manifold, necessary gaskets, and most importantly, a custom tune from a reputable tuner like Lund Racing. The engine will not run correctly without a tune.
2. Depressurize and Disconnect: Disconnect the battery. Relieve fuel system pressure. Remove the engine cover, air intake tube, and throttle body.
3. Disconnect All Attachments: Label and disconnect all sensors, vacuum lines, and fuel lines attached to the manifold. This includes the fuel rails and injectors.
4. Remove the Old Manifold: Unbolt the manifold from the cylinder heads. Carefully lift it off, ensuring no small parts fall into the engine.
5. Clean and Prepare: Thoroughly clean the mating surfaces on the cylinder heads. Install new intake manifold gaskets.
6. Install New Manifold: Carefully lower the new manifold into place. Hand-tighten all bolts, then follow the specific torque sequence and specification for your new manifold.
7. Reassemble and Tune: Reconnect all sensors, lines, the throttle body, and intake. Reconnect the battery. Load the new custom tune file into the vehicle's ECU via your tuning device before starting the engine.

As one owner shared regarding modifications: "So far, just has intake, exhaust, hood, rims and window/taillight tint. I need to get this thing on the lift and see how good all the bushings n shit is tho." This underscores the importance of a thorough approach to any modification project.

Parts and Tools Needed

For PCV/Oil Consumption Fix:

• Oil Catch Can Kit (e.g., UPR, J&L, JLT specific to 2020+ Mustang GT)
• Basic hand tools: screwdrivers, pliers, socket set
• Zip ties for hose management

For Intake Manifold Replacement/Upgrade:

• Aftermarket Intake Manifold (e.g., Ford Performance Boss 302, GT350, or aftermarket like Cobra Jet)
• New Intake Manifold Gasket Set (Motorcraft ML3Z-9S478-A or equivalent)
• Throttle Body Gasket
• Custom ECU Tune (from Lund Racing, Palm Beach Dyno, etc.)
• Hand tools: comprehensive socket set, torque wrench, torx bits, extensions
• Fuel line disconnect tool
• Shop towels and intake cleaner
• Threadlocker (for manifold bolts if specified)

Real Owner Costs

Costs vary dramatically based on the path chosen.

DIY PCV Catch Can Install:

• Parts: A quality catch can kit ranges from $150 to $300.
• Tools: Basic tools most owners already have.
• Total DIY Cost: ~$150 - $300. This is a pure parts cost for a 1-2 hour job.

DIY Performance Manifold Swap:

• Parts: A Boss 302 or GT350 intake manifold can cost $800 - $1,500 used or new. Gaskets and fluids add $50-$100.
• Tune: A custom tune from a renowned tuner is $500 - $800.
• Total DIY Parts & Tune Cost: ~$1,350 - $2,400. This does not account for your time, which could be 6-10 hours for a first-timer.

Professional Shop Costs:

• For a manifold swap, shops typically charge 4-6 hours of labor. At an average rate of $120/hour, that's $480 - $720 in labor.
• Total Professional Cost (Manifold + Tune + Labor): ~$2,300 - $3,900+. One owner's experience with modifications highlights the value placed on professional work: "You can find the usual intake, exhaust, lowered, rims all day on marketplace. I’d go for yours over that any day", suggesting a well-executed, tuned modification is worth more than bolt-ons without proper setup.

Prevention

Preventing issues related to the intake manifold system is straightforward. For the stock setup, the best prevention for oil-related issues is the proactive installation of an oil catch can. This simple modification protects your intake valves from carbon buildup and stabilizes oil consumption. Choose a quality can with a drain valve for easy maintenance.

If you are considering performance modifications, prevention means doing your research and using quality parts paired with professional tuning. Never install a performance intake manifold without the required custom tune; you risk running the engine lean, causing severe damage. Regularly inspect the engine bay for loose hoses or fittings, especially after any work has been done. Keeping the engine's software updated with the latest calibration from Ford can also address any factory drivability quirks.

What Owners Say

Real experiences from FORD owners:

Owner Experiences

"I keep the original engine that had been rebuilt but not used yet wrapped up. It has aluminum heads, RPM air gap intake, Brawler carburetor. 4 speed top loader, 3.73 gears, just finished installing all new ginger interior." — Potential-Coast-1034 (source)

"It has aluminum heads, RPM air gap intake, Brawler carburetor. 4 speed top loader, 3.73 gears, just finished installing all new ginger interior. Made over 450 hp on dyno." — Potential-Coast-1034 (source)

"You can find the usual intake, exhaust, lowered, rims all day on marketplace. I’d go for yours over that any day" — AnonMushroom97 (source)

Pro Tips from Owners

💡 "First tip: it’s not worth it, the gen 3 manifold is pretty much on par with the boss 302 for airflow. Second tip: get a JLT intake and a tune from Lund and don’t waste your time on a manifold." — Aggravating_Feed_896 (source)

💡 "Second tip: get a JLT intake and a tune from Lund and don’t waste your time on a manifold. If anything get a ported gen 3 one." — Aggravating_Feed_896 (source)

Real Repair Costs

"Modification Questions - 2020 GT Base Decided it was time for a mid-life crisis so I grabbed a 2020 GT (Base) 6 speed with 40k miles for just under $28k - squeaky clean carfax with all the service history and was Ford Gold Certified or whatever 5k miles previously." — FireBoatMcTV (source)

"Decided it was time for a mid-life crisis so I grabbed a 2020 GT (Base) 6 speed with 40k miles for just under $28k - squeaky clean carfax with all the service history and was Ford Gold Certified or whatever 5k miles previously." — FireBoatMcTV (source)

FAQ

Q: How long does it take to install a catch can or swap the intake manifold? A: A catch can installation is a beginner-friendly job that typically takes 1 to 2 hours. A full intake manifold swap is an intermediate to advanced project. For a DIYer with the right tools and a guide, expect it to take a full day, or 6 to 10 hours. A professional mechanic can usually complete it in 4 to 6 hours.

Q: Can I drive with oil being sucked through the PCV system? A: You can, but you shouldn't ignore it. Over time, the oil will coat your intake valves with carbon, potentially leading to reduced performance, rough idle, and misfires. It also means you need to vigilantly monitor your oil level to prevent engine damage from low oil. Installing a catch can is a recommended fix.

Q: Is a plastic intake manifold a common failure point on the 2020 Mustang? A: No. The factory Gen 3 intake manifold is not known as a common failure item. Most discussions around it involve upgrades for performance or addressing the ancillary issue of oil consumption via the PCV system, not the manifold itself cracking or leaking.

Q: DIY vs mechanic - what's recommended for a manifold swap? A: This depends entirely on your skill level and tools. A catch can install is firmly in the DIY realm. For a full manifold swap, if you are comfortable with fuel systems, electrical connectors, and following a precise torque sequence, DIY is possible with careful preparation. However, given the absolute necessity of a proper custom tune, many owners choose to have a reputable performance shop handle the entire swap and tuning process to ensure it's done correctly. As evidenced by owner advice, the tune is critical: "get a JLT intake and a tune from Lund and don’t waste your time on a manifold."

Q: Will a manifold swap from a Boss 302 or GT350 pass emissions? A: This is a critical consideration. In many states, especially those with visual inspections (like California), swapping to an intake manifold that is not certified for your specific model year can cause you to fail emissions testing. Even with a tune that manages emissions, the visual discrepancy can be a problem. Always check your local regulations. One owner noted the scrutiny: "bro no way, the guy doing the smog check literally tried to peel the sticker off telling me it wasn’t legal."

Q: Do I need new valve covers to fix the oil consumption? A: A catch can is the first and most cost-effective solution. However, as owner SLNTGT pointed out, upgrading to aftermarket valve covers like the Voodoo units can provide a more permanent design fix: "Voodoo valve covers move the intake port to the side of the baffle so it’s a noticeable improvement." This is a more involved and expensive fix but addresses the problem at its source.