I think a lot of high mileage reliability comes down to proper maintenance. I've developed a pretty good routine over the years, but I'm always looking to learn more.
What are your essential maintenance tips for high mileage cars? Beyond the obvious oil changes, what specific things do you do to keep a vehicle running smoothly past 200k? I'm particularly interested in things like timing belt/chain maintenance, transmission fluid changes, and addressing small issues before they become big problems.
My top maintenance tips for high mileage cars: First, oil changes are non-negotiable. I do mine every 5k miles with full synthetic. Second, address small issues immediately - that weird noise or small leak will become a big problem if ignored.
Third, keep records of everything. Knowing when you did timing belts, water pumps, etc., helps you stay on top of preventive maintenance. Fourth, use quality parts - cheap parts fail faster and can cause collateral damage.
Transmission fluid changes are critical for longevity. Many people never change it, then wonder why their transmission fails at 150k miles. I do drain and fills every 30k miles on my automatic transmission cars.
Cooling system maintenance is also huge. Replace coolant at recommended intervals and replace hoses and the radiator before they fail. A cooling system failure can destroy an engine quickly.
Regular inspections are key. Every oil change, I check brakes, tires, suspension components, and look for leaks. Catching worn components before they fail prevents more expensive repairs later.
Also, don't ignore the little things like engine mounts, bushings, and belts. Worn mounts can cause other components to fail, and a failed belt can leave you stranded or cause engine damage.
For timing belt/chain maintenance: If your car has a timing belt, replace it at the manufacturer's interval, not when it breaks. A broken timing belt usually means engine destruction. For timing chains, listen for rattling noises on startup - that's often the first sign of wear.
Also, use the correct fluids. Don't put the wrong transmission fluid or coolant in your car. Using the wrong fluid can cause premature failure of expensive components.