Radiator nasty coolant problems.

[WillBHomesoon]

I have a 97 ext cab Tacoma 4x4 V6 3.4 It just turned 100k and for about a year now, ive been flushing out the radiator since i noticed really nasty looking brown dirty coolant. I dont know if a previous garage that worked on it put recycled brown coolant in it? Anyway, ive used prestone radiator flush twice in the last year and than good coolant, and it still comes back brownish at each oil change. Anyone familiar with this problem? Heater core maybe going bad?Thanks for your replies!

[burger]

Rad fluid is very corrosive if not changed regularly,and it may have damaged the heater core,but more likely it's eating away at the head gasket .The brown stuff is rust,and you'll probably have to put a gasket in in the next 10K.try putting stop leak thru the system to seal things up,it will buy you some time.

[Rycam]

Antifreeze needs to be mixed with distilled water. Tap water contains minerals and can mess with the pH of the solution.

Make sure your ground straps from the head/block/body are connected. If you cant locate them...add a couple of your own. They are only a few dollars each, or free at the pick-n-pull.