Brown Coolant

Today I replaced the idler pulley on my wife's 2000 SE v6 with 120K on it.It was squeaka squeaka for a while.After I did the repair I decided to check the coolant. It was at about the proper level but it didn't look right. I suctioned some up and it was brown !! The last time I checked it within the last 12 months it was green.There were no chunks in it and it was watery , not sludged up. So I know what I'll be doing tomorrow. I'll try using purified water instead of tap water.I may run some cleaner through the system.

I changed the coolant yesterday and so far so good. I drained the coolant then ran and drained straight water through it twice before I refilled the coolant. As far as the brown coolant goes I recalled that about 1 month ago I had an oil change done at a pennzoil oil change place.They do a "full" service by checking all the fluids. They did add some coolant but I wonder if they used the red coolant instead of the green.The t-stat was a bit gunky but I suspect it's the original since it had the jiggle valve in it. The t-stat I used had no jiggle valve but what I do is drill a 1/8" hole in the rim of the t-stat and install it with the hole up. That should let any air pass easily even if the motor is cold.The t-stat I used was the premium model and I checked it for proper operation before installing it. I also ran the car front facing uphill to help in removing any trapped air.

I have the OHV engine in my '02. In my last car, my tap water plugged the radiator core in 2 years. I now change (w/pre mix) every fall)

I have the OHV engine in my '02. In my last car, my tap water plugged the radiator core in 2 years. I now change (w/pre mix) every fall)

I used filtered water for 50/50 antifreeze & water.It's the water from the store for drinking and seems to be well treated.I imagine certain areas have water that has a higher mineral content.