I have a 98 Deville, and it seems to have a oil cooler in front of the Drivers side rad support. I was wondering if it was stock or if the previous owner put it on. Both my GM SPO ESI software and my 98 E/Ksp shop manual do not make reference to it. I am getting a little oil leak coming from the oilfilter area and its not the oil filter. Does anybody know if it is stock or is it part of a towing package. My Dads 99 STS does not have it.Thanks