Rockwell

Ive had this problem many times. I find that turning the key while at the same time pulling on the outside handle will get it to release. Do them both together and you kind of feel the handle assist the key to pull the linkage. Usually not on the first try, but repeat and it should eventually open the door.

2011 MP8 445 with 650K miles The Normal: Every morning for the past 5 years of ownership, I turn the key on, wait for GuardDog to complete its check, and start the motor. The motor runs very quietly, and in 4 - 8 minutes or so my turbo would spool up to about 5 or 6lbs and decrease to 2 or 3 and the sound would become a little more gnarly accompanied by a very distinct, steady whistle of the turbo. At this point on cold mornings white vapor would then start coming out of the stack. This was always my “signal” that she was about ready for work. The Abnormal: Suddenly, now when I start the truck, the motor stays in its first stage of “quiet” running, the turbo does not spool up, the gnarly sounding idle does not appear and not a hint of white vapor from the stack. The truck runs fine, pulls fine, makes about 34 lbs max boost but it now idles at 1lb. Before this, it always idled at 2-3 lbs of boost with a very distinctive turbo whine. There is no boost leak that I can find with just my hands and ears, CAC, boots, pipes all look good. Intake manifold gasket and bolts were all replaced 2 years ago and looks fine, no broken bolts. There is a “rushing air” noise near or at the EGR, this noise will suddenly stop and boom, I hear the turbo come to life, however I can find no leak, Truck has always had this noise, has even fooled mechanics into thinking there was an air leak. Keep in mind, this is all at idle. Any ideas?

Happy Thanksgiving to all! And to my fellow Truckers, Happy Turkey Day and THANK YOU, From the turkey on my plate to the fork we eat it with, and everything in between, over, and under. This is one household that KNOWS how it got to us. THANK YOU for the long days, cold nights, days away from home, and the unending miles. Thank YOU driver for a wonderful Thanksgiving with my family. Stay SAFE and Keep On Truckin, (America needs you to , whether they know it or not.)

No, keep the EPA dirt bags here and send ME back! Trucking was FUN! Made better money and the trucks literally had a soul. My Granddaddy and Daddy wouldn't even recognize what they call truckin today.

Obviously this can be many things. I dont know how this would relate to the One Box DPF/SCR set up you probably have with a 2016. On older models like mine where the units are separate, I know DEF fluid can build in the pipe leading from the DPF to SCR. This build up can form a large rock like substance of odd shape that can change position in pipe as truck moves. So laying still its creating lets say a 30% exhaust blockage, but when moved, the shape now creates a 70% blockage, reducing power. Turn another corner, or hit another bump, the "Def block" in the pipe rotates and BAM power is restored as now its back to only 30% blockage. On earlier models, its super easy to check, simply remove the braided flex from the Obama Can (DPF) to the SCR and look inside the SCR. Again, I dont know hoe this might relate to a 1 box unit. Just a thought. Good Luck.

MackTech, thank you for the response. I have to assume the truck does have rollover stability. Another symptom I've noticed when the idle races after setting parking brake. My exhaust temp guage Instantly pins itself far right and my HEST light comes on, as if exhaust temp instantly went thru the roof. If I release the parking brake and drive 10 feet, HEST light goes out and exhaust temp guage returns to normal instantly. The high exhaust temp reading is false, its only high electronically, not in reality. i did have the truck do this high idle with brake to me about 2 years ago. Mack installed new batteries while it was at the dealer shop. When i got it back, I got this symptom. I noticed they had hooked the ACM power wire to a different positive battery terminal than where it was with the old batteries. I put the ACM wire back to the original battery terminal and the problem went away. Now I know logically this dont make sense, and perhaps the resolution was just coincidental and had nothing at all to do with ACM wire. Two years later, the truck starts racing when I apply the parking brake. Some days it will do it all day, everytime. Other times it will disappear for days. Could it possibly be a weak battery causing this? Maybe a slight drop in voltage playing games with the computer? Whatever it is, it does not and has not affected operation of truck.

2011 CXU613, MP8 630K miles. Hey all, So here`s a weird one... This problem went away as mysteriously as it came. Yesterday, every time I set the tractor parking brake, (Yellow Air Valve on dash) the motor would race up to 1200 rpm, drop to about 1000, rev back up, then drop to idle and idle normally. Every single time I set the tractor parking brake. Other than that, truck performance was fine with all gauges reading normal, no MILS or codes at all. The problem disappeared towards the end of day and it hasn't done it again, including all day today. Any ideas?

Make sure it is not leaking from gasket where the ccv meets the block. Mine had a really bad leak from there, not the orings on the ccv. Quick easy replacement.

Forgive my ignorance, I'm no true mechanic, just Shady Tree, but how or what is a pressed on cam lobe??? Lobes pressed onto an otherwise perfectly round shaft??

As far as I'm aware and have heard, through no qualified source, emergency vehicles do not derate. Yes you get all the same warnings and Mils, but no derate. It is my understanding, they aren't exempt from emissions, but they are exempt from derate.

I was able to get a gasker kit no problem for mine thru H&H Mack, Rockaway, NJ. Maybe you can order it from them and have it shipped. My gasket turned brittle cause a leak. Simple, easy fix.

I have been hearing this exact statement for 3 years now in US and haven't seen it yet. I`m sure eventually it will be reality, all depends on how much money the DOT thinks it will bring in. Investment and Return!

Just in case it helps another down the road... Problem Solved. Engine harness behind engine fan had a short in the 5. volt sensor supply wire. 1 beer for fjh! You called it.

Thank you fjh, what's funny is Mack installed a new starter, got the truck back and had this problem on first run out. Awefully coincidental. All starter wires bright and tight.

Hello, 2011 Mack CXU613 MP8-445 600,000 miles(10speed) Motor intermittently stumbles or jerks on hard pull when calling for boost. Then returns to normal. When the motor stumbles, my boost pressure goes from let's say 33 to flat line. Not zero, just two dashes as if there is no reading or boost whatsoever. Looks like this... 33... Motor stumbles and display reads - -. Then it returns to normal. No codes being thrown. No other symptoms. Pressure Sensor? Actuator? Any ideas would be greatly appreciated!  Truck had had new injectors/cups and fuel filters are good. Even at idle, boost pressure will go from 2 or 3 psi to - - momentarily on center display.