Oil in the cooling system - Cars & Trucks

This will depend on if the cooler is air cooled or water cooled. With water cooled setups, yes, you will probably need to replace it.
With Air cooled setups if oil is mixing with coolant the problem is somewhere else on the engine. The most likely place would be the head gasket.

You may be pumping oil into the cooling system. Oil pressure is higher than cooling system pressure so it is possible that flow is into the cooling system or you are loosing coolant but it is being displaced by oil so it always looks full. Get a professional to check for a bad headgasket.

Hi Alan, If your vehicle has been overheated at any time, the cylinder head may have become distorted and consequently coolant may be mixing with oil if the gasket is damaged and failing to seal correctly. The job requires the removal of the cylinder head and taking it to a machining company to skim it before replacing. You were quite correct to have checked the oil cooler if it is the type which fits into the engine block and uses the engine coolant for cooling. Oil in the cooling system is not something which should be ignored. Once the problem has been solved and rectified, flush the cooling system to remove all oil deposits and then use the correct mixture of coolant to water. Regards John

Your low on oil (the tapping noise) because its in your cooling system. Your vehicle uses the radiator as a cooling system for your engine oil. It runs through it to help cool the engine oil. If you have oil in the radiator, you need a new radiator before you cause more damage to the engine and the cooling system.

Not uncoomon. If you look where the oil filter is in the front of the motor by the radiator. Where the oil filter screws onto is the oil cooler and has coolant passing around it in a jacket. The oil pressure is greater than that of the cooling system pressure. Replace that cooler and flush the cooling system. This should cure it.

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REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
2. Remove the thermostat to drain the cooling system.
3. Remove the oil filter.
4. Disconnect the hoses from the cooler.
5. Remove the nut holding the cooler to the oil filter base and remove the cooler.

To install:

1. Position the oil cooler, then connect the coolant hoses. Tighten the nut to 18 ft. lbs. (25 Nm).
2. Install the oil filter and the thermostat.
3. Fill the cooling system and connect the negative battery cable. Start the engine, allow it to warm up check for coolant leaks.

these run about $50

Thoroughly flush out the coolant expansion tank and cooling system, radiator , engine block ect... with a commercially available cooling system flush (Prestone or any other brand). Oil will damage the rubber cooling system hoses. Refill the cooling system with the correct amount of fresh antifreeze and drive the car after the cooling fans have cycled on and off. When the cooling system has cooled down top up as required and keep an eye on the cooling system for a few weeks to see if the problem reoccurs or if someone had inadvertently put oil in the reservoir.If not I'm more leaning toward a blown head gasket. it will run fine but you will have to keep the water clean out. to fix it buy a head gasket and surface the head..you have a blown head gasket

oil is getting into the cooling system through the oil cooler. the oil cooler is located under the intake manifold. After replacing oil cooler you need to flush the cooling system several times to remove all of the oil sludge

I presume that you mean oil in the cooling system. there is a leak somewhere and needs to be attended to right away.

Oil in cooling system will deteriorate the hoses...

Oil pressure is often more than cooling system pressure, which is why coolant not in the oil.

Guessing that there is a head gasket leak.....

remove oil filter. loosen 24mm hex nut holding oil cooler in place. remove oil cooler and fit seal. may need to disconnect coolant hoses from oil cooler, if so cooling system must be bled on reassembly.

What about the possibility of a crack in head gasket between oil passages and coolant passages. Oil pressure would be higher than cooling system pressure, thus oil would be more likely to enter cooling system, than coolant enter oil /lube system. Just a thought. Have you done a cooling system pressure test, just to see if any drop at all in pressure? Seeing how engine would not be running, oil pressure would be 0, and may allow coolant to seep through same path, only from cooling system, to oil. Is it a large amount that your getting?