Mercedes-Benz bulletin LI01.40-P-079518
What it saysComplaint Customer complains of oil use, oil leaking or oil smell. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Jul 16, 2025, received Jul 22, 2025, about the engine. It names 60 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.
Get the next Mercedes-Benz bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationComplaint Customer complains of oil use, oil leaking or oil smell. Upon inspection oil will be seen at or around the rear of the engine and at the engine/transmission interface. Cause Oil leaking from rear main seal and/or rear main seal plate. Remedy If the rear main seal plate has been previously replaced per the instructions in this LI, open a TIPS case before proceeding. Inspect the rear main seal very carefully. Make sure the seal is not sucked in, rolled, or cut (see pictures in attachments). Confirm the leak location is at the rear main seal and/or rear main seal plate by cleaning the area thoroughly and applying trace powder to the suspected area. Allow the vehicle to run either on a lift or at low speed in a controlled environment (do not attempt at high speed or in wet areas as this will make the results difficult to assess). If the leak is emanating from the seal: replace both air/oil separators. Then clean the bellhousing area completely and test with trace powder again to see if the leak remains. If it doesn't, release the car. If the leak remains pull the rear main seal plate, clean the block mating surface completely and replace the rear main seal plate and rear main seal. When the new seal is installed make sure the sealant path is followed exactly as it is shown per the drawing in the attachments. Apply the sealant to the BLOCK instead of the plate to ensure adequate coverage is attained. After installation lubricate a feeler gauge with oil and run it between the rear main seal and the crank to clear any small debris that may be present and to break any binding or stiction.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI01.40-P-079518 | Service bulletin | Jul 16, 2025 | 11020807 | PDF, 4,461 KB |
What the document itself lists
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| A1770103708 | Crankcase Cover 1 Must remove -CLAMPING SLEEVE | — | eBay Motors → |
| A 601 992 01 25 | CLAMPING SLEEVE | — |
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. Listings and prices on eBay Motors are the seller’s.
Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
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 themand 13 more on this site: 2023 Mercedes-Benz GLS-Class, 2022 Mercedes-Benz GLS-Class, 2021 Mercedes-Benz GLS-Class, 2020 Mercedes-Benz GLS-Class, 2025 Mercedes-Benz S-Class, 2023 Mercedes-Benz S-Class, 2021 Mercedes-Benz S-Class, 2019 Mercedes-Benz S-Class, 2018 Mercedes-Benz S-Class, 2017 Mercedes-Benz S-Class, 2025 Mercedes-Benz SL-Class, 2023 Mercedes-Benz SL-Class, 2022 Mercedes-Benz SL-Class.
Also filed against model years this site has no page for: 2022 Mercedes-Benz AMG E63S; 2020 Mercedes-Benz AMG GT S; 2022 Mercedes-Benz AMG GT63; 2022 Mercedes-Benz AMG GT63 S; 2023 Mercedes-Benz AMG S 63 E 4MATIC+; 2024 Mercedes-Benz AMG S 63 E 4MATIC+; 2024 Mercedes-Benz AMG SL63 S E.
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Email me new Mercedes-Benz bulletins for one of these models
A weekly email, sent only in a week when Mercedes-Benz files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 53 model years this bulletin names have filed 2,061 complaints with NHTSA since 2015. 565 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.
On the 2017 Mercedes-Benz C-Class, the 12 owners who gave an odometer reading for Engine reported it at a median of 36,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
My 2017 G550 misfired on a highway and I had total failure with kids in the backseat creating an immediate life-safety hazard. This issue was caused by the M176 engine, which is known to create misfires. Mercedes tried to blame it on me not changing my spark plus, but I showed proof they were changed with a certified Mercedes mechanic.
2017 Mercedes-Benz G-Class · Engine · filed with NHTSA Oct 27, 2026 · ODI 11773912
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
In depth: 2017 Mercedes-Benz C-Class engine problems → · 2016 Mercedes-Benz C-Class engine problems →
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 group84 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 LI01.40-P-079518 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 LI01.40-P-079518 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 Mercedes-Benz warranty extension on file lists the ones Mercedes-Benz has filed.
Which vehicles does LI01.40-P-079518 cover?
The manufacturer filed it against 60 model years: 2025 Mercedes-Benz AMG GT, 2024 Mercedes-Benz AMG GT, 2023 Mercedes-Benz AMG GT, 2021 Mercedes-Benz AMG GT, 2020 Mercedes-Benz AMG GT, 2019 Mercedes-Benz AMG GT and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.