Second owner of a 1996 w/ 5.9 / auto which has run hot by has not overheated. I pulled the radiator cap and found dried brown sludge under the cap and filler neck and the level is low. Checked the oil and there's no sign of water in the oil which temporarily rules out head gaskets for now.

I'm planning on power washing the cooling system and heater core Monday. Aside from poor maintenance is this indicative of other issues with these trucks?

 

Probably rust. If flushing the system doesn't help, probably a good idea to get a new radiator.

 

i would flush it good and then run straight water in it for a little bit then drain the water and see what it looks like when it comes out

 

Thanks for the quick replies!

 

what does power washing mean ? don't hit it with extreme pressure, just flush it out good with water, maybe use a radiator flush product. also locate your block drains hiding behind the motor mounts. one on each side. its a hex head and its hard to reach and prone to round off. so go ahead and get a good bite with vice grips on the first try.

 

Sounds like some one has used any number of diffrent stop leak products. I second a severe flushing of the system.

 

Stop leak, various antifreeze variants and lack of maintenance. I bought the truck from the original owner and he owned up to using dex-cool and various other antifreeze products. He changed radiator hoses a year back and filled it the cheap stuff at the parts store. So, deep clean here it comes.

By power wash I mean flush - garden hose on low constantly running with the drain open flushing out the junk. Should take a couple cycles with this crud.

For the block drains should I open then every time I drain the system... meaning the radiator drain and the block drains open at the same time?

 

napa descaler might help along with a good flush before using the descaler

 

yep. there's about a 1/2 gallon of coolant in the bottom of the block. plus, that's where all the crap settles to.