Brown Slime in top of v6 radiator

[JoshSvc]

Just popped the radiator cap to find a heap of brown slime on the bottom of it and it is coating the inside top of the radiator. Any idea what it is?

The oil is fine and isn't milky at all
The transmission fluid is a nice red colour like it should be

In all my cars i have never had this slime before...

Josh

[227shanno]

probly nothing out of the ordinary mate, maybe it just needs a coolant change. radiators on older cars are always full of crap

[greenacc]

Its probably from the radiator cooling system pellets from Holden. Its like bars leaks. Its meant to be there but your actual coolant should be nice bright green ?

[JoshSvc]

The coolant is green its just got this horrible brown shit in it lol... Thanks for the replies fellas. Much appreciated.

[alex2_s]

It's the pellets for sure, usually it builds up under the radiator cap (whilst the actual coolant stays green)... also causes the reservoir contents to turn brown as it goes via the cap and epxansion hose

[chrisdoesitbetter]

yep i would have to agree with the above, definately the pellets. my car hashada full holden service history until i bought it. i changed my coolant without the pellets and the sludgy cr*p has gone.

[Ozzie]

Sounds more like the trans cooling line is leaking inside the radiator.

Is the brown crap oily/sludgy?

If it is then its definetly the trans cooling line. A small split will only leak trans fluid into the radiator. (cooland cant get into the trans)

[crazy.vr]

You can get a build up of crap if you mix different coolants too which end up clogging radiators. Always stick to the same brand.

[Ozzie]

You can get a build up of crap if you mix different coolants too which end up clogging radiators. Always stick to the same brand.

Never heard of brown slime from mixing coolants. Cheaper coolants can blow manifold gaskets though.
In which case he would be topping it up all the time.