Mercedes-Benz warranty extension EW - Cylinder Head M264
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.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationIn 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�).
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| EW - Cylinder Head M264 | Warranty extension | Jan 10, 2026 | 11027580 | not yet checked |
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.
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.