Why Your Ford Expedition Hesitates on Acceleration (And How to Fix It)

How to Fix Hesitation

If your 2020 Ford Expedition is hesitating, stumbling, or losing power when you press the gas, you're not alone. This frustrating issue is often a symptom of underlying maintenance needs rather than a catastrophic failure. Based on real owner experiences, the problem frequently stems from worn ignition components or contaminated fuel, leading to poor engine performance. As one owner, Luis Gomez, shared after fixing his truck: "I decided on doing full plug and coil replacement problem was solved but I can tell you the original plugs were gone gap was out of tolerance and the electrode on some of the plugs seems complete burn out." The good news is that with a methodical approach, this is often a fix you can tackle yourself.

Symptoms

Owners describe the hesitation in a few distinct ways. The most common report is a noticeable loss of acceleration. You press the accelerator, but the truck feels sluggish, unresponsive, or stumbles as if it's being held back. This can happen at any speed but is particularly alarming when trying to merge onto a highway or pass another vehicle.

This power loss is often accompanied by other sensations. Some drivers report a general shake or vibration through the chassis, especially under load. In more severe cases, the hesitation can be so pronounced that it feels like the truck might stall, particularly when coming to a stop or during idle after a drive. While not always present, some owners have noted unusual rattling noises correlating with the power loss, though this is less frequently cited than the driving feel issues.

It's crucial to distinguish this engine-related hesitation from problems that might feel similar. Owners have separately reported brake problems and driveline vibrations, but the hesitation tied to acceleration is typically rooted in the engine's ability to make power smoothly. Paying close attention to when the symptom occurs is key to diagnosis.

Most Likely Cause

Based on the collective experience of 2020 Expedition owners, the most likely cause of hesitation is worn-out spark plugs and/or failing ignition coils. Over time, spark plugs degrade. The electrode wears down, and the critical gap between electrodes can widen beyond specification. This leads to a weak, inconsistent spark that fails to properly ignite the air-fuel mixture in the cylinder. The result is misfires—both noticeable and subtle—that manifest as hesitation, shaking, and a lack of power.

A secondary, but related, cause identified by owners is a contaminated or underperforming fuel system. While less common in the direct quotes than ignition issues, it is mentioned as a potential contributor. This could involve a clogged fuel filter (which is part of the in-tank fuel pump module on this model) or poor-quality fuel. A weak fuel pump or a clogged filter restricts fuel flow to the engine, creating a lean condition where there isn't enough fuel for the amount of air, leading to stumbling and hesitation, especially under acceleration when fuel demand is highest.

How to Diagnose

Diagnosing hesitation requires a process of elimination, starting with the simplest and most common fixes. You'll need a basic set of tools: a socket set with extensions, a spark plug socket (likely 9/16" or 14mm), a torque wrench, and a gap tool if your new plugs aren't pre-gapped. A code reader, while not always necessary, can be very helpful.

First, check for diagnostic trouble codes (DTCs). Use an OBD-II scanner to see if the truck's computer has logged any codes related to misfires (like P0300-P0308), fuel trim (P0171, P0174), or other performance issues. Even if the check engine light isn't on, there may be pending codes that point you in the right direction. If you find misfire codes for specific cylinders, you can focus your efforts there.

If there are no codes, your next step is a visual and mechanical inspection of the most common culprit: the spark plugs. This is a bit involved on the 3.5L EcoBoost engine but is the definitive diagnostic step. You will need to remove the ignition coils and spark plugs from a few cylinders—pay special attention to the rear ones on the driver's side, which are the most difficult to access. Inspect each plug. Look for excessive electrode wear, abnormal deposits, oil fouling, or, as owner Luis Gomez found, a gap that is visibly too wide or electrodes that are "complete burn out." Comparing old plugs can show you which cylinders are suffering the most.

Step-by-Step Fix

The most effective fix, as proven by owners, is replacing all spark plugs and, if necessary, the ignition coils. Here is a detailed guide to doing it yourself.

1. Gather Parts and Prepare: Purchase a full set of OEM Motorcraft spark plugs (SP-580 or equivalent for your specific engine). Many owners also opt to replace all ignition coils (Motorcraft DG-508) preventatively, especially if the originals have high mileage. Let the engine cool completely before starting.

2. Disconnect the Battery: For safety, disconnect the negative battery terminal to prevent any electrical shorts or accidental engine starts.

3. Remove Engine Covers: Unclip and remove the plastic beauty covers from the top of the engine to access the ignition coils.

4. Clean the Area: This is a critical step emphasized by owners. Before removing any coil or plug, use a shop vacuum or compressed air to thoroughly clean the area around the coil boot. As Luis Gomez advises, "just make sure you vacuum around the plugs first to prevent any debris getting into the engine." Debris falling into the spark plug well can enter the cylinder and cause severe damage.

5. Remove Ignition Coils: Carefully disconnect the electrical connector from each coil. Depress the tab and pull straight off. Then, remove the bolt securing each coil and gently pull the coil straight up and out of its well.

6. Remove Old Spark Plugs: Using a spark plug socket with a long extension and a swivel joint for the rear plugs, carefully break each plug loose and unscrew it. Keep each plug in order so you can inspect them later for cylinder-specific issues.

7. Gap and Install New Plugs: Check the gap on your new plugs with a gap tool, even if they are advertised as pre-gapped. Adjust if necessary to match your vehicle's specification (typically 0.030-0.033 inches for EcoBoost). Apply a small amount of anti-seize compound to the plug threads if it is not pre-applied. Hand-thread each new plug into the cylinder head to avoid cross-threading, then tighten with a torque wrench to the specified value (usually about 15-20 lb-ft). Do not over-tighten.

8. Reinstall Coils and Reconnect: Place a new ignition coil (or the original if reusing) into each well, ensuring the rubber boot is seated properly. Push down firmly, then install the retaining bolt and reconnect the electrical connector. Repeat for all cylinders.

9. Reassemble and Test: Reinstall the engine covers and reconnect the negative battery terminal. Start the engine and listen for smooth operation. Take the truck for a test drive, paying attention to acceleration from a stop and at highway speeds. The hesitation should be resolved.

If the problem persists after a full plug and coil replacement, the next step is to investigate the fuel system. This involves checking fuel pressure, which requires a special gauge, and potentially replacing the in-tank fuel filter. As one owner noted while searching for a part, "I ordered the filter (Motorcraft FG-1036)..." indicating this is a known service item. Replacing this filter is a more advanced task, as it requires dropping the fuel tank.

Parts and Tools Needed

• Spark Plugs (8): Motorcraft SP-580 (or exact equivalent for your 3.5L EcoBoost). Confirm part number for your specific model year.
• Ignition Coils (8 - Optional but Recommended): Motorcraft DG-508.
• Fuel Filter (If needed): Motorcraft FG-1036 (in-tank module filter).
• Basic Tool Set: Sockets (including a deep-well spark plug socket, 9/16" or 14mm), ratchet, extensions (6-inch and 12-inch), swivel/u-joint adapter, torque wrench.
• Other Supplies: Spark plug gap tool, anti-seize compound, dielectric grease, shop vacuum or compressed air.
• Diagnostic Tool: OBD-II code reader (helpful but not mandatory).

Real Owner Costs

The cost to fix hesitation varies dramatically between DIY and professional repair, as the quotes clearly show.

DIY Cost: If you do the work yourself, your cost is purely for parts. A set of 8 quality spark plugs costs approximately $80-$120. A full set of 8 ignition coils adds another $200-$400. So, a complete DIY plug and coil job can range from $80 to over $500, depending on how many components you replace and the brand you choose.

Professional Repair Cost: Taking your truck to a shop, especially a dealership, is significantly more expensive. The labor is the major factor. As one owner, member11, found when shopping around: "No one would touch it for less than $400 so I figured I'd rather it be done by someone with experience. The local Ford dealer was the lowest quote I received." Another owner, Adieu, referenced labor costs around $300 for the same job. Therefore, you can expect professional spark plug replacement to cost between $400 and $800 when parts and labor are combined. For a plug and coil replacement at a dealer, the total could easily exceed $1,000.

These figures highlight the massive savings of the DIY approach. As Adieu pointed out, "once you get the break-ey 07-08 original plugs out the first time around, there's absolutely no need to spend $300 labor on a simple procedure the second time around." The same logic applies to the 2020 model.

Prevention

Preventing hesitation is about adhering to a strict maintenance schedule. The single most important thing you can do is replace your spark plugs at or before the manufacturer's recommended interval. For the 3.5L EcoBoost, this is typically around 60,000-100,000 miles, but many owners find performance degrades sooner. Proactive replacement at 60,000 miles is a wise investment.

Secondly, be mindful of your fuel. Use Top Tier detergent gasoline from reputable stations to keep fuel injectors clean and avoid carbon buildup. While the fuel filter is designed to last a long time, including it in a major service (e.g., every 100,000 miles) can prevent fuel-flow related issues. As owner Trainmaster suggested for overall health, "While unrelated, it wouldn't hurt to change the transmission fluid too. Then you'll be up to date with maintenance and your problem will probably go away." Keeping all fluids fresh contributes to the overall smooth operation of the powertrain.

What Owners Say

Real experiences from FORD owners:

Owner Experiences

"I'm back now to disclose some issues I've had. First off- My AC was 22 pounds low so, the local Total Care mechanic put dye in with the top-off so he can check for leaks in a week." — Donny Kelley (source)

"I ordered the filter (Motorcraft FG-1036) through O'reilly's website. Might have to send it back if I can't find it or doesn't exist outside the tank...Thanks!" — BluBlocker (source)

"The answers you are getting and the installation of dye in your AC smacks of incompetence. You can get advice here, but you need someone real who looks at that truck." — Trainmaster (source)

Pro Tips from Owners

💡 "On idle it was fine. I decided on doing full plug and coil replacement problem was solved but I can tell you the original plus were gone gap was out of tolerance and the electrode on some of the plugs seems complete burn out. not a hard job to do yourself if you handy with a wrench just make sure you vacuum around the plugs first to prevent any debri getting into the engine and torque down the new plugs. the rear ones are the hardest to reach." — Luis Gomez (source)

💡 "I decided on doing full plug and coil replacement problem was solved but I can tell you the original plus were gone gap was out of tolerance and the electrode on some of the plugs seems complete burn out. not a hard job to do yourself if you handy with a wrench just make sure you vacuum around the plugs first to prevent any debri getting into the engine and torque down the new plugs. the rear ones are the hardest to reach." — Luis Gomez (source)

Real Repair Costs

"You're absolutely right, but I couldn't convince/assure any other mechanic that the first set had already been replaced. No one would touch it for less than $400 so I figured I'd rather it be done by someone with experience." — member11 (source)

"I guess my main question there would be: Can they check for Transmission Fluid Leaks when they flush, or do they need to remove the Radiator? Because I know a Flush Job does not run $800!" — Donny Kelley (source)

"No one would touch it for less than $400 so I figured I'd rather it be done by someone with experience. The local Ford dealer was the lowest quote I received." — member11 (source)

FAQ

Q: How long does it take to fix the hesitation by replacing spark plugs? A: For a moderately experienced DIYer, replacing all eight spark plugs takes about 2 to 4 hours. The rear plugs, especially on the driver's side, are time-consuming due to tight access. A professional mechanic at a shop can typically complete the job in 1.5 to 2.5 hours.

Q: Can I drive my Expedition with hesitation? A: You can, but you shouldn't for long. Driving with a severe misfire caused by bad plugs can damage the ignition coils and, more importantly, allow unburned fuel to enter and overheat the catalytic converters. This can lead to a repair bill thousands of dollars higher. If the hesitation is minor, it's less risky, but you should address the problem promptly.

Q: Is hesitation a common issue on the 2020 Expedition? A: Based on owner discussions, it is a reported issue, but it is almost universally tied to maintenance items like worn spark plugs rather than a inherent design flaw. The 3.5L EcoBoost engine is powerful but demands timely plug changes to run smoothly.

Q: DIY vs mechanic - what's recommended for this fix? A: If you are handy with basic tools and have patience, this is a very rewarding DIY job. The quotes show a labor cost savings of $300-$400. The steps are straightforward; the main challenges are access to the rear plugs and ensuring no debris falls into the cylinders. If you are uncomfortable with this, paying a professional is wise. As member11 concluded after getting quotes: "I figured I'd rather it be done by someone with experience."

Q: My plugs were just changed, but I still have hesitation. What's next? A: If new plugs and coils don't solve it, the next likely suspect is the fuel system. You should have the fuel pressure tested. The in-tank fuel filter (Motorcraft FG-1036) could be clogged, or the fuel pump could be weak. This requires more advanced diagnostics, potentially involving a mechanic with a fuel pressure gauge and scan tool that can monitor fuel trim data.

Q: Could a transmission problem cause hesitation? A: While transmission issues can cause sluggishness or shifting problems, the hesitation described by owners—specifically a stumble or shake on acceleration—is classic engine misfire behavior. However, as a general maintenance tip, old transmission fluid can affect overall driveline smoothness. A fluid change is good preventative care but is not the primary fix for engine hesitation.