E70 35D mechanical water pump failure model

[JGard]

Originally Posted by Ron07x5

First I do not know any statistics, especially about the x5.
But I think mechanical water pump failures are rare in cars in general.

Now what happens often and would be smart to replace is the thermostat.
When a thermostat fails and it sticks closed the engine overheats and.when bmw overheat.they can blow head gaskets or.crack heads.

Fyi my x5 service records show the prior owner had a thermostat failure at about 75000 miles and it overheated and blew a hose.

If your x5 is about the same miles it would be good to replace it. Also reminds me the x5 doesn't have a temp gauge. I need to get my bmwhat iphone reader hooked up so I can have that info.

Uhh, water pump failures are a pretty common failure item. I know in the Miata world (my secondary car) you need to get those water pumps replaced when you do the timing belt, so 75-100k miles. They will begin leaking somewhere around 100-110k quite often.

As for the X5 thermostats, every failure I've heard of is a failure in the open position, not closed. So while it causes its own set of problems, it's not nearly as catastrophic as if it was stuck shut.