Hey guys! I've been seriously looking at a g37 however my mechanic told me that if the water pump goes out I will have to replace the full engine. Please help me out because that seems a little far fetched!

 

I heard that if your tires don't have any tread left, you have to replace the entire wheel.
But hey, that's what my mechanic said.

 

Your mechanic is illiterate.
Find a new more literate mechanic

 

Your mechanic needs to find a new profession. Buy the car and make the best decision of your life. Double that if you choose to find a new mechanic as well.

 

If the water pumps impeller is plastic and it let's go, then yea the engine likely be really damaged to the point of not being repairable. This problem even happens with Porsches and other high end cars. Now a car with a good maint history that includes coolant changes then it should be okay.

 

Perhaps the OP misinterpreted his mechanic. Based on the FSM, the mechanic is partially correct. Major disassembly is involved in replacing the water pump. It's driven by the timing chain and is located behind the timing chain cover.

From the pics below, I really don't see this part failing any time soon.

 

Good post Solo^^^

Welcome to the site Robert, if you consider getting a G look for a 2012+, previous years have an inferior timing gasket that can cost upwards of $2k to R&R.
Other than that these cars are very dependable.

 

It's actually a pretty ingenious design. Many cars still use external pumps these days (belt or electrically driven). I'm sure each design has its pros/cons. Really though, what is there to fail other than the seals.

I suppose if you ever need a timing chain/guides replaced, doing the pump at the same time is wise.

 

I've torn apart my engine and it comes down to the mechanic being lazy and not wanting to deal with the cause of the timing issues, and timing cover troubles he has to go thru. Its honestly easier to replace the engine instead of doing all this.

 

Also its pretty neat having the water pump run off the timing chain cause I drove my car a good bit to get it home with the serpentine belt torn.. car never over heated obviously cause its time chain driven and not belt driven like other cars.

 

Just had my water pump start leaking r&r of timing cover replacing coolant , water pump, and synth oil change. Gonna cost me 850 bucks. Fair price ??