Description

This is a fully reconditioned Garrett GT18V turbocharger for the Mercedes E270 CDI, fitted with the OM647 engine. Rebuilt at our Birmingham workshop by experienced technicians, this unit is balanced to a higher tolerance than the original manufacturer’s specification and is supplied as a direct-fit replacement part.

This unit is a variable nozzle turbine (VNT) turbocharger, identified by the part number 709836-5004s. The VNT system utilises adjustable internal vanes to precisely control exhaust gas flow against the turbine wheel. This design is key to providing the strong, linear power delivery and fuel efficiency expected from the OM647 diesel engine. However, this complexity also introduces specific points of failure. The most common issue we see with these units is the seizure of the VNT mechanism due to excessive carbon and soot build-up, which leads to either under-boost or over-boost conditions and often forces the vehicle into a reduced power ‘limp mode’. Another frequent fault is the failure of the electronic actuator that controls the vane position; its internal components can wear over time, causing erratic performance and triggering engine management fault codes. Standard mechanical wear, such as failure of the CHRA (Centre Housing Rotating Assembly) bearings and seals due to oil supply issues, is also a possibility.

What this turbocharger fits

This reconditioned turbocharger is a direct replacement for the original Garrett unit fitted to the Mercedes-Benz E-Class E270 CDI models manufactured between 2002 and 2008. It is specifically intended for vehicles equipped with the 2.7-litre, 177 HP OM647 diesel engine. The primary OEM part number is 709836-5004s, which may also be cross-referenced with the Mercedes part number A6110960899. To ensure compatibility, we always recommend confirming the part number on the identification plate of your vehicle’s original turbocharger before purchase.

At Gap Turbos, our reconditioning service involves a complete strip-down and ultrasonic cleaning of all components. Critical parts, including bearings, seals, and piston rings, are replaced with new, high-quality items. Each unit is then reassembled, and the VNT mechanism is calibrated on a flow bench before the entire rotating assembly is balanced on our VSR machine at over 150,000 RPM. We offer this unit on an exchange basis or can provide a complete drive-in, drive-out fitting service at our workshop. This service includes replacing the engine oil, oil filter, and air filter as standard.

All our reconditioned turbochargers are supplied with a 12-month warranty. Please contact us with your vehicle registration for a precise quote and to confirm stock.

Specifications

Vehicle fitment

• Mercedes E270 CDI

Common faults & troubleshooting

• Sudden loss of power or vehicle entering “limp mode”: This is the classic symptom of a seized variable nozzle (VNT) mechanism due to carbon build-up, preventing correct boost regulation.
• Loud whistling or siren-like noise during acceleration: This usually indicates a boost leak in the pipework between the turbo and the engine, or potential damage to the compressor wheel fins.
• Visible blue or black smoke from the exhaust: Blue smoke points to failed oil seals inside the turbo’s core (CHRA), allowing engine oil to enter the intake or exhaust. Black smoke can indicate over-fuelling caused by incorrect boost levels.
• Engine management light (EML) on: Fault codes relating to ‘boost pressure deviation’ or ‘actuator position’ often point directly to a failing electronic actuator or a stuck VNT mechanism.
• Noticeably poor fuel economy: A worn or failing turbocharger operates inefficiently, meaning the engine has to work harder and use more fuel to produce the required power.

Fitting notes for this unit

• Pre-installation oil prime is mandatory: Before connecting the oil feed pipe, use a syringe to squirt 5-10ml of fresh engine oil directly into the turbo’s oil inlet port. Gently spin the compressor wheel by hand to ensure the new bearings are fully lubricated.
• Replace service items: Always fit a new turbo with fresh engine oil (to the correct Mercedes specification), a new oil filter, and a new air filter. Failure to do so can cause immediate damage and will void the warranty.
• Inspect oil feed and drain lines: The oil feed and drain pipes on the OM647 engine are prone to internal carbonisation and sludge build-up. These must be thoroughly cleaned or, for best practice, replaced to guarantee unrestricted oil flow.
• Use all new gaskets and seals: Do not reuse old gaskets. The supplied fitting kit includes a new manifold gasket and oil drain gasket; ensure all mating surfaces are perfectly clean and flat before assembly.
• First start procedure: After installation is complete, start the engine and allow it to idle for at least 5 minutes. Do not rev the engine. This allows oil pressure to stabilise and fully circulate through the new turbocharger before it is subjected to high rotational speeds.
• Check for leaks after warm-up: Once the engine has reached operating temperature, perform a final check for any oil or exhaust leaks around the turbocharger and its connections before road testing.

Alternative part numbers

This turbo is also referenced by:

• A6110960899 — Mercedes Turbocharger OEM A6110960899 (Mercedes E270 CDI, OM647, 177hp)

Frequently asked questions