Mystery Coolant Leak C250CDI (W204, 2012)

[anonymous-user]

Anyone know of any likely causes? Needs topping up every 1500 miles. Had a pressure test on it but it held for 4 hours.

[mk1coopers]

Water pump seal ?, could be leaking when operating and hot, static cold test might not show it

[SomeDubber]

Had the same problem on my old Merc, it was the weeping water from the water outlet fuel filter housing.

As it turns out its quite common on these engines, I got a modified kit from Mercedes to do the job. Part number: A651 200 60 00

Hope this helps!