The Heinz

Was going to suggest EGR cooler, but that apparently won't be a problem for you (Very smart of you). We've seen oil cooler/side cover failures before on both 11 and 13 liters, that could very well be your issue. I also wouldn't discount the possibility of the head gasket leaking, but we rarely see that at all.

I don't exactly want to make it public, but I'm not super far from you. MP's and mDrives are absolutely my biggest money maker, that's for sure.

Hey ya'll, I've been lurking long enough I figured it was time to make an account. I've been a parts salesman at a Mack dealer for 3 years now with 3 years of Mack fleet technician experience prior. For the past 3 years I've been working as the shop parts salesman here, which flowed nicely with my previous experience, and has enhanced my knowledge and love for old Macks. Sadly, the oldest truck we've had so far has been in the early 90's, but my love for the days of semis long past keeps me invested in the field. That and my ever-increasing hatred of Volvo and the bastardization of the Mack name. Yes, a 26 year old is allowed to have good taste. I'll try to browse the Parts Wanted section to see if there's anything I can help with, but unfortunately my resources only cover trucks that are so old. Anything to help the cause!

I'm by no means qualified, but it sounds like your SCR might be dead. Pretty much every truck with 4094 that rolls in our shop leaves with an SCR. There were some times new NOx sensors resolved the issue, but most resulted in the truck getting a new SCR. Did you use an OEM NOx sensor? Most aftermarkets we tried ended up not working, to the point our shop won't use them at all.