The seals of the coolant pipe running between the cylinder banks harden, and the coolant starts to leak. The pipe runs in the V valley of the engine, under the intake manifold, so the leak is not visible from outside: the fluid collects under the intake manifold and only appears through a weep hole.

What the owner notices is that the coolant goes down, but there is no puddle. If the seal has let go, the loss becomes rapid, and the low coolant warning appears as well. The fault appears above 120 000 kilometres and can lead to overheating.

The factory repair is outstandingly expensive on this engine: to get the pipe out, the timing chain cover, the chain, the intake manifold and the cylinder head all have to be disturbed, and that is over 40 hours of work, with a bill above 4000 dollars. That is exactly why two aftermarket routes exist: a liner pushed into the old pipe, at around 1000 dollars, and a collapsible pipe that can be fitted without opening the engine, at between 1500 and 2500 dollars.

One thing is worth asking. Workshops usually replace the gasket of the alternator bracket and the seals of the valley pan in the same job, because they are reached from the same place. If the pipe has been done, the other two are worth looking for on the invoice.