m7mikim

I had my "external" water pump replaced on my 2012 F150 3.5L ecoboost at 97K. I'm the original owner of the truck and purchased the extended warranty back in 2012. I was shooting the bull with the mechanic that did the job, and he was telling me that the 3.5L ecoboost engines have two water pumps on one engine. That there is an internal and external water pump? Is this true? Not sure why you would need two water pumps?

Missmy06

Not true, the FWD car based 3.5 Ecoboost, ie the one in the Taurus, Explorer, Flex, etc uses the internal waterpump. The truck based 3.5 Eco, the one we have, uses the external waterpump. This is a good thing as the internal waterpumps have a reputation for failing and flooding the engine oil with coolant causing catastrophic engine failure.

m7mikim

Missmy06 that’s what I thought. After looking at timing chain replacement videos I saw that the timing chain idler was just that an idler and not a water pump. However ther is a potential for that gasket to leak coolant into the timing chain housing, but that’s just as likely has a head gasket failure.