Forgive the ignorance but do intercoolers leak oil ?

[ukmastiff]

Please forgive my ignorance , I did try googling it but as far as I'm reading your oil doesn't go through the intercooler. Why am I being told by a mechanic that my oil leak is coming from where a pipe comes out of the intercooler ( and that the intercooler 'must' be replaced).

Helpfull folk her have pointed out that intercooler o rings are known to perish but , I dont understand that this would cause a fairly major engine oil loss can someone explain for me does oil go through there or is it not just air ?.

Regards

Mas