I'm curious if the oil can be mixed with the coolant into the radiator only, but not into the engine.

I check, check and check the oil and nothing! In every change the oil is clean and coolant free.


Any idea?

Thanks,

Denis V.

 

Automatic transmission, right?

The radiator has an oil cooler for the transmission built into it. If the oil cooler starts to leak, you'll get oil in the coolant, but no water in the engine.

 

AND, you will have water in the transmission. Better check the fluid there to be sure.

 

If you have an engine oil cooler you can get engine oil into the coolant as well. Since oil pressure is greater then radiator cap pressure any leaks will go into the coolant.

It's possible to get some coolant back into the oil with this type of leak when the motors shut off and the oil pressure drops, but coolant pressure doesnt. This may not happen though if it takes say.. 30 psi to make it leak. The oil pressure is greater then that but water pressure is lower so it'd be all one way.

 

I suppose that if the block was cracked, you could also get the same results as you described.

 

Oh, thanks guys for all replies!

1.- I'll check the trans fluid, but, since the radiator was replaced in 2001, I think all is good with this stuff.

2.- "Oil pressure is greater than coolant pressure". This is new for me. Until now, I thought the inverse. This is very possible. The last weekend I did a travel (about 500km/300 miles) and the oil was down and coolant was up a little.

3.- Block was cracked, welded and machined in 2001. Problem started this year.

Thanks every one for your help,

Denis V.