Oil cooler leaking antifreeze into oil?

mgjonesin · Post by **mgjonesin** » 26 Apr 2011, 14:49

Just got a lab test back for the oil.

"excessive antifreeze in the oil"

I'm thinking oil cooler.

No visible milkiness, and I did a block test for exhaust in the coolant (head gasket OK).

Anyone have any experience with this?

Thanks,

Post by **VCA** » 26 Apr 2011, 15:16

mgjonesin wrote:Just got a lab test back for the oil.

"excessive antifreeze in the oil"

I'm thinking oil cooler.

No visible milkiness, and I did a block test for exhaust in the coolant (head gasket OK).

Anyone have any experience with this?

Thanks,

I have seen it happen. But I don't think this car has an oil cooler inside the radiator. What engine does yours have? AWD or FWD?

Post by **precopster** » 26 Apr 2011, 18:50

All Volvo straight sixes have an oil cooler. This is either a separate unit or integral with the radiator.

Either replace with an aftermarket oil cooler (by bypassing the factory one) or replace the entire cooler. Do you tow?

mgjonesin · Post by **mgjonesin** » 26 Apr 2011, 19:20

It's a T6 AWD, the cooler mounts on the back of the oil pan and has coolant lines running to it.

No I dont do any towing (I want the trans to last longer).

Post by **precopster** » 26 Apr 2011, 20:05

If it's not integral with the radiator then you have a problem.

The only other thing available might be the head gasket.

Just because exhaust (carbon monoxide) is not in the coolant it doesn't mean a breach of the HG b/w engine oil and coolant jackets hasn't occurred.

You would be testing for (CO) only if you saw excessive bubbles in the coolant reservoir or overpressurisation of the coolant system.

mgjonesin · Post by **mgjonesin** » 26 Apr 2011, 20:46

The oil cooler is not integral with the radiator but it has coolant running through it. It's not a air to oil cooler, it's a antifreeze to oil cooler. Coolant is pipped to a manifold at the back of the engine that supplys the oil cooler and the turbos.

Post by **precopster** » 26 Apr 2011, 20:49

That must be an immense relief to you!!

voodoorobaz · Post by **voodoorobaz** » 26 Apr 2011, 21:44

I Have had same symptoms in my 2000 volvo xc70. It was the oil cooler mounted to the oil pan. They reason you have oil in coolant and not coolant in oil is this. Oil pressure is 25-80 psi and coolant is around 16psi. Oil cooler has micro cracks which allow oil to leak at a psi greater than 16, Hence oil in coolant. I hope this makes sense. I troubleshot it by getting a small pipe, taking both coolant hoses off of oil cooler and connecting them together. Now start the car and watch oil cooler tubes and you will see oil coming out which won't take long at all.

Post by **VCA** » 27 Apr 2011, 05:18

voodoorobaz wrote:I troubleshot it by getting a small pipe, taking both coolant hoses off of oil cooler and connecting them together. Now start the car and watch oil cooler tubes and you will see oil coming out which won't take long at all.

Yup, and when you see oil coming out, it's part 30622090 for the cooler. Change the gasket as well, that's part 30637339.

mgjonesin · Post by **mgjonesin** » 14 Jun 2011, 08:14

New oil cooler has fixed the problem! No more dissapearing coolant.