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The water pump isn’t driven by the timing belt, it’s driven by an accessory belt - usually the big serpentine one that also drives the alternator, PS pump, etc. On cars with a timing belt, as opposed to a timing chain, the timing belt is a maintenance item that needs to be replaced at some point but to get to the timing belt one usually needs to remove the water pump. As long as one’s removing the water pump they may as well put a new one back on since the labor’s the same. This is why the water pump usually would be replaced if one’s changing the timing belt. Ditto the radiator hoses and often the serpentine belt or other belts.</p>
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Well, there could have been a bad leak because of it and if someone didn’t pay attention they could have overheated the engine but that’s true for a radiator hose or a radiator leak or any other leak as well. In my experience the water pump ‘typically’ doesn’t leak that catastrophically. They usually start with a fairly slow leak where you notice a tiny puddle under the car for days or even weeks. They usually leak past the bearing in the front. You can also usually smell the anti-freeze smell from the leak. In other words, there’s generally time to get it taken care of without risking a major coolant dump/overheating situation unless one pays no attention whatsoever to their car. A keyword I used here is ‘typically’ because there are exceptions.</p>
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Please tell that to my Dodge! I generally don’t get much more than that, or even that, out of that water pump on that particular car. I buy lifetime warranty replacement pumps from Autozone and just keep having them give me another one for free so I only spent about $40 for the 4 pumps I’ve gotten from them for this car. The replacement lasted as long as the factory one so I don’t fault the replacement one. How long the water pump will typically live depends on a lot of things including the design of the pump and engine, the environment it’s driven in, whether one maintained the cooling system properly, etc.</p>
<p>Bottom line - if you’re buying a used car, especially one with mileage above 50K miles, you should expect a likelihood of some maintenance having been done and a replaced water pump is considered a normal item - not a big red flag like an internal engine problem or something which it sounds is the angle you’re looking at this and hence your concern. Moreover, a manufacturer certified warranty to 100K miles protects you assuming the time duration is reasonable as well - i.e. if you have another couple of years in time and mileage before the end of the warranty then that’s pretty good. Most dealers have already done a fairly extensive check of the vehicle before offering the certified warranty since they don’t want to lose money by having to do a lot of warranty work on it.</p>
<p>Besides, you’ll be saving a lot of money anyway due to it being a used car so some maintenance wouldn’t usually be a big deal financially.</p>
<p>I think you should eliminate the variable of this WP having been replaced from your decision process on this.</p>