PACCAR bulletin E335
What it saysExpiration Date Format Update - Certain EPA21 compliant PACCAR MX-13 engines were built with intake valve springs that could fail. NHTSA’s full summary ↓
PACCAR filed this with NHTSA as an emissions communication dated Jul 18, 2026, received Mar 5, 2026, about the engine — 6 documents under this number. It names 23 model years across Kenworth, Peterbilt and Paccar (2021–2023). An 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.
One page for every brand it was filed under. Each brand’s bulletins: Kenworth · Peterbilt · Paccar.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationWhat it applies to, as the document itself states it — the build window in the manufacturer’s own words, read by machine from the PDF NHTSA serves. The build date is on the certification label in the driver’s door jamb; the dealer settles a borderline vehicle by its VIN.
Expiration 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 | 11033356 | PDF, 260 KB |
| E335 | Service bulletin | May 15, 2026 | 11033354 | PDF, 287 KB |
| E335 | Emissions | Apr 11, 2026 | 11032289 | PDF, 226 KB |
| E335 | Emissions | Mar 25, 2026 | 11030932 | PDF, 425 KB |
| E335 | Service campaign | Feb 20, 2026 | 11029643 | PDF, 299 KB |
What the document itself lists
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 2264673PE | Supplier Code 85971 SRT Code B26-11A | 4.5 hrs |
Read by machine from the document NHTSA serves (6 pages), read Sep 30, 2026. A part number is shown only where it matches PACCAR’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 themKenworth 9 model years
Also 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.
Peterbilt 13 model years
Also filed against: 2022 Peterbilt 365; 2023 Peterbilt 365; 2022 Peterbilt 367; 2023 Peterbilt 367; 2021 Peterbilt 389; 2022 Peterbilt 389; 2023 Peterbilt 389; 2021 Peterbilt 567; 2022 Peterbilt 567; 2023 Peterbilt 567; 2021 Peterbilt 579; 2022 Peterbilt 579; 2023 Peterbilt 579.
Paccar 1 model year
Also filed against: 2021 Paccar MX-13.
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.
More bulletins about the engine
Source: same model, same component group20 other manufacturer communications filed against these PACCAR models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Kenworth list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| E340 | Emissions | Oct 16, 2026 | KW Certain vehicle model year 2026 Kenworth chassis equipped with EMY2025 PACCAR MX engines require an amended engine label. The engine labe… |
| P001 | Service campaign | Sep 11, 2026 | "KW: The chassis list has been updated to include 1 chassis. The total chassis count is now 53. A link to the PACCAR Powertrain Prognostics… |
| P003 | Service campaign | Sep 3, 2026 | "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to incl… |
| P002 | Service campaign | Sep 3, 2026 | "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to incl… |
| E316 | Service campaign | Aug 1, 2026 | 235 chassis have been removed from the chassis list and unflagged in PRWS due to expiration of applicable warranty coverage. 5 chassis have… |
| CE033 | Warranty extension | Jun 25, 2026 | "KW & PB 14 fuel injector part numbers (seven for MX-11 and seven for MX-13 engines) have been added to this warranty policy." |
| CE031 | Warranty extension | Jun 24, 2026 | "KW & PB 14 fuel injector part numbers (seven for MX-11 and seven for MX-13 engines) have been added to this warranty policy." |
| 99-051 | Emissions | May 18, 2026 | There is an update to the CARB Base Emissions Warranty Limits table and Manufacturer’s Warranty Coverage section in certain Engine Model Yea… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Kenworth, Peterbilt and Paccar, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is PACCAR 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 23 model years across 3 brands (Kenworth, Peterbilt and Paccar): 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. The document itself sets the build window: built 16 Dec 2021 – 9 May 2022 — the build date is on the certification label in the driver’s door jamb.