Oil drops in coolant, no intermix

[heymanwatchthis]

I have a new issue with my 2001 986S that I am having trouble sorting out, and would appreciate hearing your thoughts. Car has 107k miles, is driven regularly and runs beautifully.

While checking my coolant, noticed a slimy white film on the cap and around the fill opening. Same stuff floating on top of coolant. Not mixed with coolant - the coolant is clear, nice and pink. Just changed the oil, it and filter looked great with no signs of incursion of any foreign material. Oil level remains steady.

I removed the slimy stuff - when put on paper towel, it is the same color as oil. At this point the coolant tank was clean (although tank is old and faded) and coolant clear all the way to bottom of tank.

Took a spirited drive for about 30 min, came back and found more slimy stuff floating on top of coolant. You can see it in the attached picture - the globs of slimy stuff, and that coolant is clear to bottom of tank.

I think the slimy stuff could be from one of four sources:

1) Residual gunk from when car was built.
2) What is left of different type of coolant the previous owner used - coolant I drained and replaced with pink Porsche coolant was green.
3) Leaking heads, which is an issue with this era (2000-2002) M96. However I would think this would result in more oil incursion and intermix.
4) Oil cooler leak. This is my prime suspect, as the amount of oil is very small, and may be making its way to the coolant tank via the vent line that comes from top of cooler to the reservoir.

I have done a lot of reading, looks like others have had a similar issue that was caused by the oil cooler. Before I buy an oil cooler and hope for the best, thought I would reach out to you guys on the forum to see if you have been through a similar experience, or have thoughts to share.

Thanks!

Gary