Mercedes-Benz warranty extension EW - Cylinder Head M264
What it saysIn our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC is extending the warranty coverage on the exhaust valve… NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a warranty extension dated Jan 10, 2026, about the engine. It names 19 model years (2018–2023). A warranty extension is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC is extending the warranty coverage on the exhaust valve system in certain Model Year (MY) vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 15 years/150,000 miles, whichever occurs first. This extended warranty applies to the condition described below that may necessitate the repair or replacement of components related to the exhaust valve system on the 4-cylinder engine M264. (e.g. exhaust valve, cylinder head). The exhaust valve guide and/or seat may wear irregularly over time due to increased lateral forces during operation. This could potentially cause a combustion misfire, resulting in an activation of the check engine Malfunction Indicator Lamp (“MIL”).
One of the 432 warranty extensions and special-coverage programs on file — every make, with the term each runs to.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| EW - Cylinder Head M264 | Warranty extension | Jan 10, 2026 | 11027580 | PDF, 177 KB |
What the document itself lists
Parts the bulletin names
| Part number | Description | Qty |
|---|---|---|
| A 2640109007 | Parts Kit, Cylinder Head | — |
| A 2640106607 | — | — |
| A 2640106407 | — | — |
Read by machine from the document NHTSA serves (3 pages), read Sep 30, 2026. A part number is shown only where it matches Mercedes-Benz’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote.
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 themA 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 19 model years this bulletin names have filed 1,023 complaints with NHTSA since 2015. 283 of them name Engine — 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.
I brought my car in for routine service and was told I needed a rear main seal. I had the car inspected when I purchased it appx 13k miles ago because I saw online there was a lot of people having this issue with their vehicles. It’s a known manufacturer defect. At that time there was no issue. Now at 40k miles it began to leak.
2019 Mercedes-Benz E-Class · Engine · filed with NHTSA Jan 4, 2026 · ODI 11708627
On July 7, 2026, my 2022 Mercedes-Benz GLE 350 experienced a serious engine malfunction. After stopping at a traffic light, the engine began shaking violently and idling roughly. When the traffic light turned green, the vehicle accelerated extremely slowly and had very little power, making it difficult to clear the intersection.
2022 Mercedes-Benz GLE-Class · Engine · filed with NHTSA Jul 13, 2026 · ODI 11749953
Engine compartment heat causes wiring harness insulation to melt and Electrical shorting while driving. Engine has lack of power and acceleration due to heat damage to the engine harness. Check Engine light came on. This is a potential fire risk and should be address by MBUSA. This is a know issue with this model.
2020 Mercedes-Benz GLE-Class · Engine · filed with NHTSA Feb 9, 2026 · ODI 11716779
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 engine
Source: same model, same component group59 other manufacturer communications filed against these Mercedes-Benz models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI18.00-P-073137 | Service bulletin | Sep 26, 2026 | Complaint Sporadic warning message in instrument cluster "Engine oil pressure stop switch off vehicle" (or similar) is shown in red on vehi… |
| LI20.10-P-075374 | Service bulletin | Sep 17, 2026 | Complaint Red coolant warning in instrument cluster. Fault codes U019F00 or U019F87 current/stored in MRG1 control unit. Cause Various cause… |
| PSL-NCU Return Parts 8/14 | Other | Aug 15, 2026 | Dear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be ret… |
| LI01.20-P-080884 | Service bulletin | Aug 12, 2026 | Complaint Oil leaks found on M176 or M177 engines diagnosed to be from the cylinder head cover area Cause Unknown (under investigation) Reme… |
| LI07.10-P-080384 | Service bulletin | Aug 7, 2026 | Complaint Customer reports Check Engine Light with possible loss of power concern. The Following DTC's are present • P210185 - The throttle… |
| NCU - 2026010004 | Service campaign | Jul 27, 2026 | • Always use the latest XENTRY Diagnosis software release with all available add-ons. • Make sure to follow the operation steps exactly as d… |
| LI20.10-P-072886 | Service bulletin | Jul 24, 2026 | Complaint Check Engine Light ON with DTC P012800 "The Coolant Temperature is Below the Specified Temperature" active and/or stored in the ME… |
| Emissions - 2024100016 | Emissions | Jul 24, 2026 | Mercedes-Benz AG (“MBAG”), the manufacturer of Mercedes-Benz, has determined that on certain MY 2019-2021 C-Class, G-Class, GLC, GT, S-Class… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Mercedes-Benz, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mercedes-Benz EW - Cylinder Head M264 a recall?
No. A warranty extension 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 EW - Cylinder Head M264 repair free?
A warranty extension is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.
Which vehicles does EW - Cylinder Head M264 cover?
The manufacturer filed it against 19 model years: 2023 Mercedes-Benz C-Class, 2022 Mercedes-Benz C-Class, 2021 Mercedes-Benz C-Class, 2020 Mercedes-Benz C-Class, 2019 Mercedes-Benz C-Class, 2023 Mercedes-Benz E-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.