I have been told that if you have oil and water mixing in the oil pan, most likely, it is a cracked head or a blown head gasket. If you have oil mixing in the radiator with the anitfreeze and not in the oil pan, is the result the same? What condition would allow oil to mix with anitfreeze in the radiator and not get water in the oil pan? The camaro I picked up for my daughter has oil in the rad but no water in the oil pan. Gonna replace the engine but just curious if this is indication of just an intake gasket leak or a head gasket leak.

Thanks,
osduck5

 

Assuming it is oil in your rad:
In many cases its a push shove situation. Coolant can only reach about 17lbs PSI. Oil can hit 60+ PSI. So with a small crack between an oil passage into the radiator (coolant passages). This would mean a none fixable cracked block in most cases

Reality is it is most likely not oil. Its blow by from the cylinder. It will quickly cause the coolant system to gum up with a dark soot. This is caused by a cracked head or the ring around the head gasket has blown into a coolant passage (the most comon failure). Quick check is to start the car up cold. See how long it takes for the rad hose to get hard from pressure. Most likely it will be almost instant. If it does you know what you got.

 

Correct me if im wrong, but if you have an intake gasket or plenum leak, you will get water in your oil, but oil will not get into your coolant. A bad head gasket, cracked head, or cracked block (anything exposed to combustion pressure or oil pressure) can cause oil to end up in the radiator.

 

could also be the oil cooler.

 

With our engines it is very unlikely oil will get into coolant from the head or the head gasket becuase there is no oil pressure in going thru the head or head gasket. It is possible that if there was no pressure in the coolant system oil could get in but it would be a very small amount. Now with an overhead cam car the headgasket is a very likely source for oil in the coolant.

 

Wait,,, what?
Are you talking about a transmission cooler?

 

not sure if the 6s have a engine oil cooler or if it was a auto so i just said oil cooler.

 

Not trying to be belligerant, just trying to learn -- even overhead valve designs like ours still have oil pressure in the head though, correct? How do the rockers stay lubricated?

 

The lifters work as pumps, the push rods are hollow and the oil sprays all over the valves.

 

This car is a 3.8L with auto tranny. The antifreeze has a cream colored slimy sludge in it, oil looks good and the engine is not locked up but will not crank over, it tries to turn over but stops like if you were trying to start it with a very weak battery. Thinking one of the cylinders may be full of water. Going to pull the plugs this weekend to see if anything comes out and if I can crank the engine over.