oil in the radiator reservior??

[mopar440cu]

What would cause oil in the radiator reservoir in my 1996 Pontiac sunfire with a 2.4? There is NO anti freeze in the oil. Which is a relief!

Could it be a intake manifold or possible auto transmission oil leaking in? Cant seem to find the leak.

I don't understand how either one of these could leak into it, but I am reading further on it. Any help would be appreciated!

 

[melsg5]

Is your transmission fluid low or contaminated? Try a cooling system pressure test.

 

[Zimgxp]

The oil is at a higher pressure than the coolant. It will push into the oil if they are mixing somewhere.

 

[mopar440cu]

Thanks