Anyone catch honest john on saturday's telegraph?
Honest John's agony column | Honest John | Motoring | TelegraphUp the creek...
My Nissan X-Trail 2.2 diesel is little more than two years old and is already on its third turbo. On the last occasion the intercooler was also replaced. If I keep the car after the manufacturer warranty expires, can I expect some hefty servicing bills?
W.W., via email
# In a different context, another reader explained why diesel turbochargers sometimes fail: "The Exhaust Gas Recirculation valve should open to allow carbon dioxide (which acts as a cooling gas) into the combustion chambers when the engine is under load (more than 30 per cent boost). This allows the combustion chamber temperature to drop and thus the temperature of the exhaust gases. If it sticks in the closed position the exhaust gas temperature will rise, causing the turbo bearings to fail and eventually allowing engine oil into the induction system. This can cause the engine to run on its crankcase oil until it is either stalled or goes bang. Problems with EGR valves are also often the cause of rough running when the valve is stuck in the open position as well. In several cases turbos have blown but the EGR valve has not been replaced. Inevitably the new turbo unit will not last long." The most common cause of the EGR valve sticking is dirty, sludged or otherwise contaminated engine oil.