Mercedes-Benz GLB 180 d

Like its Renault counterpart, the OM608 uses a timing belt. Prescribed change every 120,000 km or 6 years -- frequently forgotten as Mercedes buyers are accustomed to timing chains.

Symptoms: No warning on snap -- sudden engine failure and severe engine damage

The OM608 (Renault K9K base) uses a timing belt. Mercedes specifies 200,000 km change interval; Renault prescribes 120,000 km for the same engine. A snap causes immediate total damage on this interference engine.

Symptoms: No noticeable warning before snap; beforehand: faint squealing, occasionally starting difficulties

The Renault-based OM608 1.5 CDI sometimes shows increased oil consumption from early on due to a leaking turbocharger shaft seal. Oil mist in the intake tract behind the turbo.

Symptoms: Dropping oil level, oil mist or blue smoke from exhaust, oil in air filter housing behind turbo

As a Renault K9K derivative, the OM608 shares the known EGR valve weakness. With frequent short-trip use, soot particles accumulate, the valve seizes and triggers limp mode.

Symptoms: Engine warning light, power loss, limp mode at around 3000 rpm, increased fuel consumption

With predominantly short-trip use, the OM608 is prone to DPF blockage. Regeneration intervals shorten until active regeneration is no longer sufficient and the filter must be manually regenerated or replaced.

Symptoms: DPF warning light, frequent active regeneration, fuel dilution in oil, power loss

On 70,534 GLB X247 and A-Class W177 vehicles (production 2019–2020, Mexican manufacture only) the corrosion protection on the front axle subframe was inadequate.

On early production GLB X247 the body in the area of the front wheel arches was not correctly sealed. Water could enter the front footwell and damage control units.

On GLB X247 model years 2019–2020 the lateral spoiler elements on the tailgate could detach at high speed and endanger following traffic.