Hey guys, ive got a 4.0 thats rusting on the inside. Anyone know of a miracle concoction i can run through my coolant system to knock that rust out and maybe even prevent it from happening more in the future? Any ideas are appreciated!

 

Flush repeatedly with distilled water, once water is all clear drain and fill with distilled water/coolant mix.

 

Flush and then run a cleaner through it then flush till clear water comes out, make sure the heater heat control is on high so all the water can flow in it also to clean. Then replace thermostat and any hoses that look old at that time.


The rust comes from a PO not running coolant in the engine/radiator or was way to old to be effective. Change every 2 years to keep things in good shape.

 

Agreed, the problem is that the previous owner(s) neglected the cooling system or it sat for a long time. Using the proper 50/50 coolant mix, running it often enough to circulate, and changing it every few years will prevent it from rusting. If your heater core is really gummed up with crap though a flush might not be good enough. For the engine a flush should be enough though.