I would say that you should try to flush the block, radiator & heater core with water first to see how that goes. If you want something more aggressive, go with an actual cooling system flush chemical rather than soda...

Then start looking for the leak cause there is one somewhere that has allowed air into the system.

 

i waskinda weary of the whole "Coke" flush-and such a waste, IMO! hahahahaha.

you think air contaminated the coolant, causing this "sludge"? 'cause i sure don't see any traces of coolant leaks anywhere-unless it's @ the back of the engine...........

personally, i think it was just the lady who owned the truck (since new) before me. i had my friend @ GM look into the service history on the truck, where she bought it. even though there were current records right up to the Fall before i bought it, once it was out of warrenty, she did the bare minimum-at best-for the health of the truck.

 

Even something as simple as a bad radiator cap can allow air into the system. Once air is in the system, it can rust the metal. I can get into the reasons why, but do not want to pull this thread off topic.

 

funny that you mentioned the rad cap. i just replaced it last week when i did the thermostat-noticed that it had little spring pressure to it.

what was the stuff you were refering to for the flush? i'll take a guess it's a GM product?

 

There are several different brands. Prestone has their flush kit that makes it somewhat easy to do.

 

have you checked the range on your tps

 

have you read through the whole thread?

i know you're new to the site, but please do before posting a reply (read it all, and you'll see what i'm getting @).

 

preston makes a 10 minute super flush and also a 3 to 6 hour super cleaner.....i only tryed to 10 minute one becuasei cant leave regulator straight water in my radiator for long with these cold temperatures here...

 

thanks for the info bdk, i'll check it out.

 

Rather than Coke, try using Vinager, It eats the rust and corrosion, without the sticky burnt on sugar mess.