Is this oil in my radiator?

[opihinalu]

Car overheated yesterday and I opened up the radiator a few minutes ago and found brown sludge. Is this oil? If so whats wrong? Cracked head gasket?

 

[Mstng93SSP]

Looks like corrosion to me. This happens when people run regular tap water in their radiator. Flush the radiator and cooling system completely and refill with distilled water and anti freeze/coolant.

 

[General karthief]

That's just rusty crud

 

[KRUISR]

Comes from the coolant passages in the block. We have 30+ year old engine blocks that are cast iron. Unless flushed with regularity, this is the norm.

 

[opihinalu]

Looks like corrosion to me. This happens when people run regular tap water in their radiator. Flush the radiator and cooling system completely and refill with distilled water and anti freeze/coolant.

That's just rusty crud

Comes from the coolant passages in the block. We have 30+ year old engine blocks that are cast iron. Unless flushed with regularity, this is the norm.

Thank god. This is my daily so i would be in trouble

 

[7991LXnSHO]

On a 4.6, either the oil filter adapter seal leaked or the quick lube got the PS fluid and coolant tank confused. It did not look like that, but was a mess. The tanks are clearly marked now.