I_Like_Waffles

yup. checked over everything. Found the CAC had exploded up top and somehow with the sound/heat pad on the hood it pushed down on the cooler and would seal it off and would not notice the boost lose. since it was intermittent I'm guessing a bump or road conditions had an effect where the engine bay would shake and boom boost leak galore.

sounds good. I can definitely see boost tapering off when the egr opening. its weird how it wont log codes.

new speed sensor. new pigtail. no codes logged at all. like nothing. yes we lose throttle.

motor runs fine. no miss or vibrations from the engine at all. its usually when its running.

yes they are. the speedometer sometimes drops out and comes back on. if that is any helpful to know then there u go.

Hello there! Currently have 2 2008 Mack trucks with the MP8 motors in them. I'm having issues with both of them getting up to speed. There is a intermittent issue going on with these trucks. Ive changed the foot pedals, speed sensor, and speed sensor pigtails. These issues happen randomly. They just cant get up to speed. Sometimes they wont go past 45 mph sometimes 55mph. Does anybody have any feedback on what to check on these trucks. I'm at a loss. Both are equipped with a 13 speed and 1 has a check engine light (lighting bolt) for a crank case breather code. The other shows nothing.