Porsche bulletin No. 14-21
What it saysInstallation and conversion instructions for information on measuring the wheel system (manthey) NHTSA’s full summary ↓
Porsche filed this with NHTSA as a service bulletin dated Sep 16, 2025, received Apr 5, 2021, about the wheels — 4 documents under this number. It names 24 model years (2016–2025). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationInstallation and conversion instructions for information on measuring the wheel system (manthey)
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| No. 14-21 | Service bulletin | Sep 16, 2025 | 11024132 | PDF, 8,699 KB |
| No. 14-21 | Service bulletin | Apr 7, 2023 | 10235383 | PDF, 2,946 KB |
| No. 14-21 | Service bulletin | Apr 13, 2021 | 10191731 | PDF, 65 KB |
| No. 14-21 | Service bulletin | Mar 26, 2021 | 10189908 | PDF, 39 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themAlso filed against model years this site has no page for: 2021 Porsche Cayman GT4; 2021 Porsche Redundant Boxster; 2021 Porsche Redundant Cayman; 2023 Porsche Redundant Cayman GT4.
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 20 model years this bulletin names have filed 169 complaints with NHTSA since 2015. 36 of them name Engine, Wheels — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
On my 2021 Porsche Cayenne Base, which is equipped with the 3.0L V6 EA839 engine, I brought the vehicle to the dealership for a recall service. During inspection, the dealership found a leaking water pump and quoted $8,500 for repairs. There were no visible signs of a coolant leak on the ground, indicating an internal seal failure.
2021 Porsche Cayenne · Engine · filed with NHTSA Aug 31, 2026 · ODI 11760942
While travelling on the freeway on 7/30/23, I experienced a "low oil pressure, shut down engine immediately" warning. I pulled over to the shoulder and was unable to restart the car. It was towed to Porsche Carlsbad dealership where it is awaiting analysis by Porsche. The car has 4900 miles on it and is under the MFG warranty
2021 Porsche 718 · Engine · filed with NHTSA Aug 7, 2023 · ODI 11537030
While driving 40 miles per hour a sudden explosion happened with no warning. Thought it was the engine due to the smoke coming out of rear of the vehicle but realized that engine was still on and steam was coming out. All coolant drained out of vehicle and on road. Vehicle was towed to a Porsche dealership in Duluth Ga.
2017 Porsche 911 · Engine · filed with NHTSA Sep 24, 2025 · ODI 11689476
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the wheels
Source: same model, same component group58 other manufacturer communications filed against these Porsche models under the same component group (wheels), newest first. The eight newest are listed; the rest are on the Porsche list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| No. 33-26 | Service bulletin | Sep 29, 2026 | Technical information for AC Charging Process in the Customer’s Home Network Not Working on the Macan Electric |
| No. 22-26 | Service bulletin | Aug 31, 2026 | Manufacturer's Certificate for approved wheels and tires |
| 24-26 | Service bulletin | Aug 31, 2026 | Manufacturer's Certificate for approved wheels and tires. Also includes model year 2024 911 S/T and GT3 Touring. |
| 23-26 | Service bulletin | Aug 31, 2026 | Manufacturer's Certificate for approved wheels and tires |
| 14/26 | Service bulletin | Jul 24, 2026 | Approved: Wheels and Tires (14/26) |
| WRS6 | Service campaign | Jul 20, 2026 | Porsche intranet posting with information on workshop campaign WRS6 - readjusting control unit for tire pressure monitoring. |
| 40/26 4407 | Service bulletin | Jun 30, 2026 | Wheel Bolt Replacement Requirement - Change from Wheel Bolts with Aluminum Washers to Wheel Bolts with Steel Washers (40/26) |
| 09/26 4400 | Service bulletin | Jun 24, 2026 | Approved: Wheels and Tires (09/26) |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Porsche, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Porsche No. 14-21 a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the No. 14-21 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every Porsche warranty extension on file lists the ones Porsche has filed.
Which vehicles does No. 14-21 cover?
The manufacturer filed it against 24 model years: 2024 Porsche 718, 2023 Porsche 718, 2022 Porsche 718, 2021 Porsche 718, 2025 Porsche 911, 2024 Porsche 911 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.