Hey guys,

recently I was driving on the highway and my car began to rapidly rise in temps and I started smelling foul burnt coolant odor. I had nowhere to pull over so I had to keep the car running for about 2 minutes and the temp gauge was at maximum. When I finally stopped the car and popped the hood, I noticed the lower radiator hose simply took the day off and was disconnected. I don’t remember if I loosened the hose clamp or not but when I reattached it the clamp was a little loose so I’m hoping that’s what happened. Took rad cap off and there is a brown mud/dirt like substance coating the radiator and I assume is filling the rest of the system. I attached pictures below.



What happened? Is this a sign of a blown head gasket? Does it just need a solid full system flush? The radiator is new and car has been running for a while with no problems and it was installed properly so I know that it’s not the problem. Could this have happened after the lower radiator hose slipped off and maybe the air in the system caused this? It’s not a particularly oily/viscous sludge, it’s more like a really fragile/soft clay or soil almost.

Do a full flush, and only use distilled water. That mud may be due to minerals from tap water, or someone added stop leak additive.

That looks like you mixed 2 different coolants that didnt get along. You will need to do a flush, a couple actually but I doubt the radiator will come back to life. No telling if the head gasket is fried just yet either.

thanks for the input, I’ll definitely do this. I think it might be from tap water but I never put tap in this car and have no idea why it would take this long for something like this to happen. My guess is it finally gave way and clogged the system while I was driving and caused the hose to pop off?

never mixed coolants, I did mix two different brands ( O’Reilly and Napa) but they were identical coolants as far as type is concerned. Both 50/50 green.

What was in it before you did the radiator swap?

The brownest, most disgusting Coca Cola I’ve ever seen. I’m not sure what the previous owner might have put in it but the car ran fine and cool for a long time up until this point where everything went from 0-100. I think the guys theory about stop leak could be plausible. If someone put stop leak in because of some problem in the engine who knows if the gunk came from my engine block (hope not). I think the radiator will be fine but I will have to flush it for a long time. It wasn’t smoking or anything.

I wouldn't even try to clean that thing. Replace it, the water pump and thermostat, flush the block and don't look back.

Did you flush or rinse out the system before you swapped out the radiator? Still thinking there may have been leftover junk in the system.

I agree this is probably needed, however, in the meanwhile, flush and run your system with tap water, empty every day or so, their is a drain **** on rad, just keep doing it till it runs clear

THEN swap out all the above parts, they are cheap as dirt. If you actually installed a new rad into the swamp water, I would advise another, but you may get away without one

If the system will not run clear, you need a new rad, it will take at least 10 changes. Tap water is fine, just make sure you use the correct coolant when done

You probably need to use strong engine block cleaning products (in your clear water), nothing worse than skanked up water passages in your engine block

I have personally seen them so silted up, they looked like the Mississippi Delta

I'd take the thermostat out and then start a flush procedure. Drive it around a while, longer than what the directions say on the bottle of flush, then rinse and repeat. The 2nd flush you could let the chemical sit in there over night after you ran it through for half n hour or so... just to let it eat away at some more of the really stubborn deposits.

Dont forget about electrolysis in your cooling system also. That can make things bad too, adding rust, aluminum oxide, and tiny pieces of you aluminum parts.... like the radiator.