Here's a breakdown of what makes it challenging:
* Accessibility: The water pump is often tucked away in a tight engine compartment, making access difficult. You might need to remove other components (like belts, pulleys, or even the fan) to get to it.
* Draining Coolant: You'll need to drain the entire cooling system before you start, which involves locating and opening drain plugs. Make sure you have a container large enough to hold all the coolant.
* Bolts and Fasteners: Rust and corrosion can make removing bolts and fasteners difficult, potentially requiring penetrating oil and specialized tools like sockets, wrenches, and possibly even an impact wrench.
* Timing Belt/Chain (Depending on Engine): On some G20 engines, the water pump is driven by the timing belt or chain. Replacing the water pump might require removing and reinstalling the timing belt/chain, a procedure that requires precise timing and alignment to avoid engine damage. This is significantly more complex and necessitates a thorough understanding of engine timing.
* Seals and Gaskets: Properly sealing the new water pump is crucial. Using the correct gasket and applying sealant correctly is important to avoid leaks.
* Coolant Refill and Bleed: After installation, you'll need to refill the cooling system with the correct coolant mixture and carefully bleed the air out of the system to prevent overheating.
In summary: While a mechanically inclined person with the right tools and some experience could tackle this, it's not a quick, easy job. If you're unsure, it's best to take it to a qualified mechanic to avoid potential damage to your engine. A repair manual specific to your year and engine is highly recommended.
