EOC (Engine Oil Cooler) is located in the center of the engine under the engine cover and intake manifold

This photo is looking straight down at the top of the engine after the engine cover has
been removed. Once the cooler begins to leak, it will pool oil in the center gallery of the engine
block between the cylinder heads.

When enough oil collects it will spill out over the transmission (usually when making a sharp turn). As the leak becomes worse, these splash over events will become
more common and oil on the ground will be more noticeable.

This is what the oil cooler assembly looks like. It allows engine oil to flow in proximity (without mixing) to the engine antifreeze. Failure involves the plastic portion of the component warping resulting in the failure of the seals to contain the engine oil under pressure.

The unit is replaced as a completed assembly after removing the upper intake manifold.

Depending on the Km on your vehicle. This is also an opportunity to replace spark plugs as the intake manifold must also be removed to replace them. (if you are at, close to, or over 160,000 Km).

The fellows in the lube shop will look down past the engine oil filter when the are replacing it to see if there is any oil starting to pool in the area described. If there is they will make a note of it for your future consideration.

If you have any questions, please stop in and I can have a look at the severity of the leak and perhaps suggest a timeline to address it. These cooler assemblies often fail in either very hot or very cold conditions. Supporting the conclusion that the plastic components warp resulting in seal failures.