Some 2020-2022 Mustang GT500 vehicles may exhibit a lack of power and/or an illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P1228. This may be due to the one-way clutch on the supercharger drive assembly. With the supercharger belt removed, a failed one-way clutch within the pulley rotates freely in both directions. The supercharger drive assembly KR3Z-6J022-B is now available as a lower level service part, separate from the supercharger assembly. Refer to the parts catalog and Workshop Manual (WSM), Section 303-12 for installation.
full bulletin at NHTSA ↗2020 Ford Mustang engine problems
moderate Owners of the 2020 Ford Mustang have filed 13 NHTSA complaints about the engine, typically surfacing around 72,000 miles at roughly $3,100 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Failure mileage
Complaints
13
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2016 Mustang | 62 |
| 2017 Mustang | 27 |
| 2018 Mustang | 51 |
| 2019 Mustang | 45 |
| 2020 Mustang (this page) | 13 |
| 2021 Mustang | 7 |
| 2022 Mustang | 3 |
| 2024 Mustang | 4 |
When does it fail?
Of the 13 engine complaints filed for the 2020 Ford Mustang, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
Some 2020-2022 Mustang GT500 vehicles may exhibit a lack of power and/or an illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P1228. This may be due to the one-way clutch on the supercharger drive assembly. With the supercharger belt removed, a failed one-way clutch within the pulley rotates freely in both directions. The supercharger drive assembly KR3Z-6J022-B is now available as a lower level service part, separate from the supercharger assembly. Refer to the parts catalog and Workshop Manual (WSM), Section 303-12D for installation.
full bulletin at NHTSA ↗Some 2011-2024 Mustang and F-150 vehicles equipped with a 5.0L engine may exhibit a tick tap and/or typewriter ticking noise at idle after an engine oil change. It is often referred to as typewriter noise because of its similarity to the sound of a mechanical typewriter. The noise in question may be heard on some engines when engine temperatures reach 150°F (65°C) or higher and engine speed is at idle up to approximately 1700 RPM. It can typically be heard at the front wheel well and is often isolated to the transmission bell housing or oil pan area. The typewriter noise tick rate can be faster or slower and is not detrimental to the engine function or durability and has no short or long t
full bulletin at NHTSA ↗For 2015-2024 Ford and Lincoln vehicles equipped with turbocharged engines and customer concern of an engine oil leak, refer to Workshop Manual (WSM), Section 303-00 for oil leak inspection and testing methods. Ford has evaluated turbochargers replaced for oil leak symptoms and although oil may collect on the external surface of a turbocharger, it is extremely rare for a turbocharger assembly to be the root cause of the oil leak. Careful inspection of the turbocharger oil feed and drain tubes should be performed along with the recommended WSM procedures as needed. Warranty claims for turbocharger replacement going forward will be assessed.
full bulletin at NHTSA ↗Some 2018-2023 Mustang vehicles (non-Shelby GT-350) may exhibit various concerns with the active exhaust system. These may include Exhaust Mode Selection Not Available messages, and/or illuminated malfunction indicator lamp (MIL) with diagnostics trouble codes (DTCs) P26C5, P26C6, P26FE, P2BF9, P2BFB, P26C7, P2BF5, P2BF8, P2BFD and/or P2BFA. This may be due to an improperly seated exhaust system. To correct the condition, follow the Service Procedure to diagnose the tailpipe actuator.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2020 Ford Mustangs report a clear pattern of engine failure tied to coolant intrusion into the cylinders, with most failures occurring between 53,000 and 66,500 miles. The failure typically begins with a check engine light and rough running, progresses to misfiring and overheating, and ends with complete engine failure requiring long block replacement. One owner had a dealer note low, dirty coolant during a pre-warranty-expiration service visit but the dealer never flagged the issue—the engine failed two months later at 61,640 miles, just past the 60,000-mile warranty cutoff.
Head gasket failure is the underlying cause in most documented cases, allowing coolant to escape into the combustion chambers. One owner had a head gasket replaced independently but the problem recurred. Ford has offered partial warranty coverage in isolated instances but denied claims citing mileage or time limits, even when owners report no prior symptoms. Several owners were steered to file NHTSA complaints rather than pursue manufacturer assistance. One case involved failed pistons and a blown engine with smoke; another showed a significant oil leak. The consistent theme: owners face unexpected total engine failure with minimal recourse during the critical 50,000–70,000 mile window.
Same Ford Mustang engine reports on nearby years: 2017 · 2018 · 2019
Failure modes owners describe
Coolant intrusion into cylinders and head gasket failure
Coolant leaks into the combustion chambers and cylinders due to head gasket failure or engine block cracks, causing engine misfiring, overheating, loss of power, and in many cases complete engine failure requiring long block replacement.
When: 53,500 to 66,500 miles primarily; one case at 86,000 miles
Symptoms owners cite: Check engine light illumination; Engine misfiring; Engine hesitation and loss of acceleration power; Engine overheating; Rough idle and rough start; Vehicle shaking; Engine misfire codes in Ford App
Codes mentioned: P0300 (multiple cylinder misfire), Cylinder 1 misfire detected
Repairs/costs cited: Long block replacement required; head gasket replacement alone proved insufficient in at least one case (narrative #6). Independent mechanic replacement of head gasket did not resolve failure. Estimated full engine replacement cost not provided by owners.
Recalls/TSBs owners mention: Ford offered partial warranty coverage in one case (narrative #3); referred owners to NHTSA Hotline in multiple cases; denied warranty coverage citing mileage or warranty expiration; made case determinations in some instances.
Failure to disclose known defect during warranty period
Authorized Ford dealer documented low and dirty coolant consistent with known coolant intrusion defect during warranty period but did not disclose findings or perform further diagnostic evaluation, resulting in warranty denial when engine subsequently failed immediately after warranty expiration.
When: At 59,968 miles during final month of 60,000-mile powertrain warranty; engine failure at 61,640 miles
Symptoms owners cite: Low coolant at minimum mark; Dirty coolant; Engine failure shortly after warranty expiration
Repairs/costs cited: No repair attempted; warranty claim denied post-failure.
Recalls/TSBs owners mention: Warranty claim denied; no recall or service bulletin response documented.
Low-pressure fuel pump failure with coolant intrusion
Engine coolant intrusion into combustion chambers accompanied by low-pressure fuel pump failure, resulting in overheating and misfiring; dealer recommended engine replacement.
When: 86,000 miles
Symptoms owners cite: Check engine light illumination; Engine overheating; Coolant in combustion chamber, engine block, and cylinder head
Repairs/costs cited: Head gasket replacement by independent mechanic did not resolve the failure; full engine replacement recommended by dealer but not performed.
Recalls/TSBs owners mention: Referred to NHTSA Hotline
Failed pistons and blown engine with internal smoke
Engine pistons failed, causing complete engine blow-out and smoke generation inside and outside the vehicle, with no prior warning symptoms reported.
When: 73,300 miles
Symptoms owners cite: Multiple unknown warning lights illuminated; Smoke inside the vehicle cabin; Smoke from under the hood
Repairs/costs cited: Engine replacement required; not performed.
Recalls/TSBs owners mention: Case filed; referred to NHTSA Hotline
Significant engine oil leak
Large quantity of engine oil leaks out onto the ground during normal operation; not further diagnosed.
When: 72,000 miles
Symptoms owners cite: Significant oil loss onto ground after topping off oil
Repairs/costs cited: Not diagnosed or repaired.
Recalls/TSBs owners mention: Manufacturer stated VIN was not under recall and could not assist
Catalytic converter and active grill shutter assembly failure
Engine warning light triggered by failure of catalytic converter and active grill shutter assembly; cause unclear but vehicle would not start or operate normally.
When: 86,000 miles
Symptoms owners cite: Engine warning light illumination
Repairs/costs cited: Catalytic converter and active grill shutter assembly replacement recommended; not performed.
Recalls/TSBs owners mention: Referred to NHTSA Hotline
Synthesized from 13 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
The contact owns a 2020 Ford Mustang. The contact stated while driving 25 MPH, the check engine warning light illuminated. The contact stated that the engine overheated while driving. The contact was able to pull over and the vehicle was towed to the local dealer to be diagnosed. The contact was informed that there was coolant in the combustion chamber, engine block, and cylinder head, and the…
I had the coolant gasket problem that resulted in having to get the engine replaced. It was a 202 mustang ecoboost premium.
The contact owns a 2020 Ford Mustang. The contact stated that after adding oil to the engine, the contact became aware that a significant amount of the engine oil had leaked out onto the ground. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was notified of the failure and informed the contact that they could not assist because the VIN was not…
Had engine trouble with your 2020 Ford Mustang?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2020 Ford Mustang?
It's a documented issue but not catastrophic. 13 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 8 complaints that reported odometer mileage, most engine failures cluster between 63,000 and 86,000 miles, with the median around 72,000. A quarter of owners report trouble before 63,000; a quarter make it past 86,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/Ford/Mustang.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.