I has sludge

[CanaryGT]

So I popped my radiator cap and on the bottom of it I have sludge. What can cause this? I also still kinda run hot even with a 180* Thermostat and a 3 core Aluminum Radiator.

 

[NERD]

Condensation could be the cause but if I had to guess. Or, I'd say you run either castrol or penzoil conventional oil and you've went to long between oil changes. (Mixing oils can also cause it.)

 

[Jetsetter]

You have oil coming out of your radiator cap? I think you've popped your radiator. You can flush it but if it looks like a mocha frappachino you're screwed.

 

[duff daddy]

Your going to get some sediment/corrosion from coolant which has been in a block for an extended amount of time, it gets pretty nasty in there, also remember there is some portion of water in the cooling system and there are steal components which will ad to this. Go look at a 4.0L jeep sometime... THOES are terrible ha ha. just get a garden hose, and disconnect the lower hose to the block and flush that system out with some water and if you can flush the heater core as well.

 

[El_Diablo]

wow... before everyone throws a thousand things out there.... what kind of sludge is it? oil? bad coolant? rust colored?

 

[MustangChris]

So I popped my radiator cap and on the bottom of it I have sludge. What can cause this? I also still kinda run hot even with a 180* Thermostat and a 3 core Aluminum Radiator.

if you have an aluminum radiator, you should only use 100% distilled water from the grocery store... you may be looking at corrosion settling to the bottom..

 

[El_Diablo]

in any kind of radiator you should only use distilled.... it minimizes corrosion on all vehicles and any water/air radiator

 

[MustangChris]

in any kind of radiator you should only use distilled.... it minimizes corrosion on all vehicles and any water/air radiator

i always use store bought distilled water (not that battery/radiator, non pottable crap from autozone..) in my coolant system, but some claim its not required unless you have an aluminum radiator.

 

[El_Diablo]

well the minerals dont help cool so why take a risk of increased corrosion? its under $1 a gallon, might aswell.......

 

[MustangChris]

well the minerals dont help cool so why take a risk of increased corrosion? its under $1 a gallon, might aswell.......

i agree. jsut saying.

but its much more important on aluminum radiators. jsut sayin' we are all on the same page... lol!

 

[CanaryGT]

Well the thing is its only on the cap. There isnt any floating in the rad at all. I dunno if its rust, cause its usually wet. Ill have to let it dry and see.