vinkodex.M260 / M264 petrol: worn valve seat / valve guide, full cylinder head replacement
Typically between 40,000 and 150,000 km. It does not show up on every car.
expensive
severity
between 40,000 and 150,000 km
mileage
2
sources
2 sources next to the write-up.
The fault
How you spot it
On the transverse M260 and longitudinal M264 four cylinder petrol engines the valve seat or the valve guide wears early. The symptom: check engine light, rough running, misfire on one or more cylinders. Sometimes without any fault code being stored.
According to the maker's official service bulletin (LI01.30-P-072328) the valve seat leaks. After the leak test, if a leak is found at the valves, the whole cylinder head has to be replaced: the valve seat cannot be refurbished. The roller width of the intake and exhaust side followers differs, and swapping them is prohibited.
In the United States the maker announced a 15 year / 150,000 mile (about 240,000 km) extended emissions warranty for the M260 group (MY2019 to 2022 A / CLA / GLA / GLB). Outside the United States that programme does not apply automatically, but the fault is the same mechanism. The GLB 250, the CLA 250 and the A 220 use this engine.
Which model
Who it affects
The card opens the generation, the engine or the transmission.
Engines and transmissions
Engine
M260DE20AL
Engine
M264DE20AL
Engine
M264E15DEAL
Engine
M264E20DEHLA
Engine
M264DE20LA
vinkodex.Checklist
M260 / M264 petrol: worn valve seat / valve guide, full cylinder head replacement
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Before you buy
Checklist
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Sources
How we know
- static.nhtsa.govNHTSA TSB LI01.30-P-072328 (Wear of valve seat or valve guide, M260/M264): leaking valve seat; cylinder leakage check; if valves leak the complete cylinder head must be replaced — seats cannot be reworked; intake/exhaust rocker rollers must not be interchangedstatic.nhtsa.gov
- static.nhtsa.govMBUSA Emission Extended Warranty (2023-08-04): MY2019–2022 A-/CLA-/GLA-/GLB-Class with M260 — valve guide and/or seat ring may wear due to increased lateral forces, causing misfire and MIL; coverage extended to 15 years / 150,000 miles; GLB 250 / GLB 250 4MATIC explicitly listedstatic.nhtsa.gov
Information, not an expert opinion
We write the descriptions, and we put the source next to them. A person reviews them before they go out. They are still information, not a technical expert opinion.
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