Engine Overview and Common Failures
The weight of the M9R engine according to the catalog is 182 kg. The M9R engine number is located at the junction of the block and the gearbox. The fuel equipment, namely Bosch injectors, is demanding in terms of diesel fuel quality and their reliability for repair is weak, but the main problems are caused by unreliable fuel pressure regulators. The search for the cause of poor starting or fluctuating engine speed should start with them.
The timing chain. This power unit was developed jointly with Nissan engineers, which is why it has a chain drive. There are completely different opinions on its resource on forums: some claim that they drive up to 400,000 km on the original chain, while others needed to replace it at 150,000 km.
Turbocharger. All versions of these diesel engines are equipped with reliable Garrett turbochargers, but errors with boost occur regularly. Usually, the vacuum system fails, the boost sensor malfunctions, or the variable geometry system of the turbocharger gets stuck.
EGR valve. Here we have a complex throttle assembly with an electronic actuator and an integrated EGR valve. This design is prone to contamination and tends to get stuck at the most inconvenient moment.
Main bearing rotation. The classic problem of bearing rotation, common to all modern Renault diesels, is also present in this engine, but it is not as pronounced as in other Renault engines.
Other weak points. Additionally, there is a relatively weak oil separator, injector sticking to the cylinder head, frequent failure of the crankshaft pulley damper, and quick clogging of the DPF (diesel particulate filter).