One of the most famous problems with this engine is water pump failure.  The pump is chain driven, behind the front cover and is difficult and very expensive to replace.  Other problems with this engine include oil leakage , a ticking noise from the engine and cracked exhaust manifolds and noise from the rear end while turning.  If you're really interested in this truck, at any price, I would have it checked out by an independent mechanic.  I, personally, wouldn't consider buying this truck at any price.

For an accurate answer, you need to provide the minimum information required at the beginning of the forum; ie, year, make, model, engine, auto or manual trans, from a dealer or private party, any codes.

Duratec V6 Engines are costly when the Water Pump starts to leak. I got a quoted for 3000 for Labor only. You said its being sold by a Dealership, I wonder if they would offer you extended warranty and I bet even if they did, they might not cover it when it goes bad. Theyre gonna hit you with "oh fine print says...."