Cooling System Rust

[BlazerBoyLT98]

Long story short I have had 4 radiators and 5 thermostats installed since last october (I only paid for one set of everything) The last time everything was fixed the shop said I have something in my system creating a lot of rust and in 2 months completely plugged a brand new radiator to the point of failure. Any ideas?

[vtmecheng]

This probably won't be the answer but when it is warm enough to not need heat try bi-passing your heater, it may be coming apart (its a long shot). Also, it may be possible that your truck used to have dexcool and was switched to the regular green stuff without adequate flushing. When the two are mixed, and it doesn't take much dexcool, the result is a brown sludge that some people mistake for rust or dirt.

[BlazerBoyLT98]

It actually looks yellowish on the inside

[BlazerBoyLT98]

Had the system power flushed for over 3 hours and it seems on the sludge is now gone and the temp is holding perfectly. Let's hope that did the trick.

[BlazerBoyLT98]

Ok so since all the work was done the temp has held, except at first when it is fully warming up it goes right past where it should and maybe hits 220 or so then creeps back down to exactly where it should be and it enver moves again. Is this normal?

[vtmecheng]

mine did that after replacing the thermostat, I exchanged it for a new one and didn't have that problem. Overshooting the temp a small amount is normal but I think 20 deg is excessive, the thermostat is probably sticking a little before opening.