Yeah so I'm embarrassed to admit this but I've been topping up my radiator with regular garden hose water for maybe eight months because I kept forgetting to buy coolant and honestly I didn't think it was a big deal. Now a friend told me that's how you get rust and scale buildup inside the engine and now I'm panicking. The car still runs fine and doesn't overheat but I'm wondering if I should get everything cleaned out properly before real damage happens. Been looking at a precision coolant system flush Dubai to try and undo my stupidity and saw Dynostar's radiator page mentions a thorough flush that removes deposits. Has anyone else done this after using tap water and did it actually clear everything out or is the damage already permanent? Really hoping I caught this early enough because I plan on keeping this car for a few more years.