Complaint -Check engine light illuminated
Mercedes-Benz technical service bulletin LI01.30-P-072328 for 2018-2023 Mercedes-Benz C300, 2020-2023 Mercedes-Benz E350 and 2019-2022 Mercedes-Benz GLC 300 and others.
- Bulletin number
- LI01.30-P-072328
- Component
- Engine
- Summary
- Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity adjustment, or misfire. Note: One or more of the above symptoms can occur. It is possible that no fault codes are stored. Cause Leaking valve seat in cylinder head. Remedy -Perform cylinder leakage check as noted in WIS group 01.00. If excessive leakage is found determine if leak is from intake or exhaust valves. -If leakage is found from intake or exhaust valves, remove cylinder head and inspect valve seats. -The complete cylinder head must be replaced if valve seat damage is found. The valve seats can not be reworked. -Engine oil and filter should be changed after the repair. Workshop notes cylinder head repair: 1. The intake rocker arm roller is narrower than the exhaust and they must not be interchanged. Mark the rocker arms so they are reinstalled in their original location. 2. Inspect all parts that are being reused (i.e. camshafts, rocker arms) for signs of wear or damage. See WIS doc AH05.20-P-1000-09SZ for examples of normal and abnormal wear. Replace parts with new if damage or wear is found. 3. Check that all rocker arms are correctly located on the camshaft before installing cylinder head cover. Rotate engine at least 2 times and check that there are no problems with rocker arms. 4. The timing chain tensioner can be reused if it extends fully, has no noticeable problems in prior operation, and no chain drive components were replaced. 5. Care must be taken when removing fuel injectors to prevent damage. See WIS doc AR07.03-P-0004-03MM. 6. Cleanliness must be observed during repair to prevent subsequent complaint or engine damage:• When cleaning engine block surface, ensure oil ports are sealed to prevent debris from entering oil circuit. Refer to SI01.40-P-0010A. • No abrasive materials, sharp-edged tools, or unapproved cleaners should be used on engine block surface. Refer to AR01.00-P-0050-01A. • Any debris from cleaning that has entered the cooling jacket should be removed before assembly of engine. The debris can otherwise cause blockage in the cooling circuit leading to engine overheating. If any of the parts listed below are found damaged or in need of replacement during cylinder head valve‑seat diagnosis or repair, and the vehicle has warranty coverage, they must be claimed on a separate parts‑only line. These items are not covered under the cylinder head warranty extension and cannot be included with the claim. • Camshafts • Camshaft adjustment solenoids • Camshaft positioners • Fuel injectors • Hydraulic valve play compensating elements • Roller rocker arms • Spark plugs • Timing chain • Timing chain guide rails • Timing chain tensioner
Owners of these vehicles have filed 298 complaints in the engine category.
Vehicles covered
- Mercedes-Benz C300 2018-2023 201820192020202120222023
- Mercedes-Benz E350 2020-2023 2020202120222023
- Mercedes-Benz GLC 300 2019-2022 2019202020212022
- Mercedes-Benz CLA250 2019-2026 20192020202120222023202420252026
- Mercedes-Benz GLE 350 2019-2023 20192020202120222023
- Mercedes-Benz GLA 250 2021-2026 202120222023202420252026
- Mercedes-Benz GLB 250 2020-2026 2020202120222023202420252026
- Mercedes-Benz A 220 2019-2022 2019202020212022
- Mercedes-Benz GLC 300 4matic 2023 2023
- Mercedes-Benz GLB 250 4matic 2020-2021, 2026 202020212026
- Mercedes-Benz AMG Glb35 2021-2025 20212022202320242025
- Mercedes-Benz AMG Cla35 2020-2024 20202021202220232024
- Mercedes-Benz C 300 4matic 2021-2023 202120222023
- Mercedes-Benz A 220 4matic 2020-2021 20202021
- Mercedes-Benz Gla 250 4matic 2021, 2024, 2026 202120242026
- Mercedes-Benz AMG A35 2020-2021 20202021
- Mercedes-Benz Cla 250 4matic 2020-2021, 2026 202020212026
- Mercedes-Benz AMG Gla35 2021-2025 20212022202320242025
- Mercedes-Benz Cla 250+ (EV) 2026 2026
- Mercedes-Benz AMG Gla 35 4matic 2024, 2026 20242026
- Mercedes-Benz AMG Glb35 4matic 2026 2026
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