jewels

having trob starting A Mack, 2011 mp8 engine, we blocked off all lines to tanks, fuel seperator, and installed 2 new filters, also made sure top and bottom chk valves were working. I only guessing its the primer pump... help

Low coolant or sending unit.

Ac fan switch.

Speed sensor, 9 out of 10 times....UPS mechanic

I had the same issue w one of our macs, it drove me nuts, it was the Egr. It had a very small in crack that would only build pressure under loads, once I R/R Egr ran like a champ and never broke down again. Hope this helps, UPS mechanic.

Thx for the help. I know this is a new Rig.will appreciate any help !

I have a 2011 Mack cxu612 w a Mp7 engine, it has a fault code of spn 5394, dose anyone no what this is.