Kenworth bulletin E335
Kenworth filed this with NHTSA as a emissions communication dated Jul 18, 2026, received Apr 7, 2026, about the engine — 4 documents under this number. It names 9 model years (2021–2023). A emissions communication 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 communicationExpiration Date Format Update - Certain EPA21 compliant PACCAR MX-13 engines were built with intake valve springs that could fail. This failure can cause significant damage to the engine. New intake valve springs will be installed.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| E335 | Service bulletin | Jul 18, 2026 | 11035150 | PDF, 215 KB |
| E335 | Service bulletin | May 15, 2026 | 11033354 | not yet checked |
| E335 | Emissions | Apr 11, 2026 | 11032289 | not yet checked |
| E335 | Emissions | Mar 25, 2026 | 11030932 | 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 themAlso filed against: 2021 Kenworth T680; 2022 Kenworth T680; 2023 Kenworth T680; 2021 Kenworth T880; 2022 Kenworth T880; 2023 Kenworth T880; 2021 Kenworth W990; 2022 Kenworth W990; 2023 Kenworth W990.
None of these model years has a page on this site (it covers EPA-certified cars, trucks and SUVs from 2016), so the bulletin is listed here on its own.
Common questions
Source: NHTSA, 49 CFR 579.5Is Kenworth E335 a recall?
No. A emissions communication 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.
Is the E335 repair free?
A emissions communication 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 E335 cover?
The manufacturer filed it against 9 model years: 2021 Kenworth T680, 2022 Kenworth T680, 2023 Kenworth T680, 2021 Kenworth T880, 2022 Kenworth T880, 2023 Kenworth T880 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.