2001 Jeep Grand Cherokee Laredo 4X4 I6 with 147,000 miles I just bought:
- Coolant was reddish brown. Removed lower radiator hose to drain, re-attached hose, filled with distilled water, ran engine with heater on HOT and HIGH with radiator cap off, topped off distilled water once thermostat opened, put radiator cap back on, ran engine while parked for 15 minutes, turned off engine, waited for coolant to cool down a bit, and removed radiator hose to drain. I did this about three times, but on the last time, I poured in 2 bottles of Prestone Radiator Flush + Cleaner and filled with distilled water.
- Drove about an hour and either the water pump decided to die or the fan clutch went out of whack ruining the water pump.
- Drained coolant and installed new fan clutch, water pump, thermostat housing, and thermostat.
- Flushed like before three times and re-did the Prestone cleaner.
- Drove about 6 hours on and off in about a day.
- Flushed like before, but after first drain, I poured in just one bottle of the Prestone cleaner. Didn't drive again. Just kept on flushing as before while parked.
- Drained and flushed with distilled water about 9 times until the water came out clear and not foamy (from the cleaner). It was dirt brown at first, but slowly got clearer with each additional flush.
- Filled with concentrated Zerex G-05 to mix with the distilled water already in the engine block and heater core. I figured this is roughly a 60:40 coolant to distilled water ratio.
- Removed and cleaned out the over flow tank with garden hose water then Dawn dish soap. Rinsed the soap out with garden hose water. Then used muriatic acid carefully to slosh around the tank to make it clean and clear. Rinsed out the muriatic acid with garden hose water and then the garden hose water out with distilled water.
- Doing just fine after doing this 3 weeks ago.
- I plan to drain the radiator and refill with 60:40 G-05 and distilled water every year or two from here on out.
- A radiator funnel with the radiator cap adapters is a must.
