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Porch Pup
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Everything posted by Rockwell

  1. 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?
  2. 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.
  3. 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??
  4. 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.
  5. 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.
  6. 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!
  7. 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.
  8. 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.
  9. 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.
  10. I need to do this same exact thing but waiting till warmer weather. I have the replacement kit. When I bought it, I had found a great YouTube video on how to replace, give it a search. As I recall, you remove the filter and push the valve out thru the top. Let me know how it goes for you! Good luck!!
  11. So would it then be wise to rebuild the heads at about 700k? Or no, to costly?
  12. I'm at 602,000 miles, only ever ran the overhead. Truck is on 3rd set of injectors/cups. Motor runs strong, oil stays clean as could be, and don't use a drop between 10k changes. I fully intend to see 1 million out of this motor before an overhaul. I'm not saying things won't break along the way obviously, but the core of the motor itself is good to go the million.
  13. There is a tool that OTR Performance sells that will reset learned data, reset ECM/ACM faults and reset soot level. Cost is about $400.00, but sure beats a tow when you derate from emissions or some such. Also a great tool to help you weed out false positives. Often times, if your able to clear the code, it never comes back. Simply plug it into the OBD port, hold fuel pedal 30 seconds and done. They say this "performs resets at the dealer level". Might help you for Actuator installation if all you need is to reset learned data without having to do any programming. Just an FYI.
  14. Hey all, So I have heard many times that the reason for the known bullgear failure (retaining nut backing off) was due to Mack raising the oil operating temp to 230 degrees. I do not see any evidence that my truck has had the Pinning Technique done, but I`m also not 100% sure. Mack tells me there are no outstanding recalls for my truck. I am having no issues with my truck whatsoever, this is more out of curiosity. My truck, a 2011 MP8 , cruises at 210-214 degrees oil temp and Im curious as to why? Shouldn't this year engine`s oil be running at or near 230 degrees? And thereby have been affected by the bullgear nut backing off.? Why does my oil stay so cool if they raised the temp to 230? My motor currently has 600K on the clock. (on its 3rd set of cups/injectors lol) Any insight is greatly appreciated.
  15. Do you know what your exhaust temp is when this happens? Boost? Have you altered the exhaust in any way? I've experienced more or less what you describe due to a clogged exhaust. Created so much Back pressure that eventually the stainless flex turbo pipe expanded itself to about 4 times its size. I had no throttle, no power, zero boost. Truck would die, basically smother itself. Would start back up, and repeat. Check for boost leaks, but also check the exhaust side. Plugged DOC, DPF, or SCR media will create what you describe. Although it should be throwing codes and calling for a regen. But I don't know year of your truck.
  16. From all my research, it seems this is a classic symptom of injectors/cups failing. The failure creates a situation where you lose prime. I will also tell you I've been nursing this problem for months. Other than difficulty starting, the truck runs strong. Sometimes I will even have to use the primer pump for 4 or 5 pumps to get life. Point is, at least for me, it is not $6K immediately! Seems you can nurse it along long enough to get your bucks in a row. I'm sure once cooler weather sets in, it may become a more immediate repair.
  17. Just wanted to follow up on this post with what the remedy turned out to be for me. Before this happened I had to replace battery cables. When hooking up the positive cables, I hooked the Positive starter cable and the ACM positive cable to the same battery stud. (prior to this they were each on a different positive battery stud). As a long shot, I decided to put the cables back exactly the way they were and POOF, problem gone. How this has any effect whatsoever i have no clue since all the batteries are connected inline to one another. All I know is my problem is gone. Maybe this will help another down the line. Thank you again fjh for all your feedback!
  18. Many thanks for your responses and suggestions fjh. When you say ambient air temp sensor, is this the same sensor that tells the dash display the outside air temp? I know that sensor is malfunctioning because sometimes i will get lightning bolt and my outside temp will disappear and just two lines appear - -. Lightning bolt goes out and temp reappears. Is this the same sensor the ECU relies on? If so, is the location in the drivers side mirror housing as I've heard? I still don't understand the correlation between this erratic idle and the parking brake, but there is obviously a connection.
  19. Thanks for that feedback. Climate is about 75F. Truck has never done this before, now it does it every time I apply the parking brake and ONLY when I apply the parking brake. As I said, truck runs absolutely perfect and has no active codes.
  20. This is a really weird one... 2011 Mack CXU613, 445 MP8, 580K miles. Whenever I set the Parking brake (yellow knob), my idle shoots way up. Set Brake, motor will idle at 650 RPM for about 5 seconds, then you hear the turbo begin to spool up and the motor revs up to 1200 rpm, as soon as it gets to about 1200rpm, you hear a slight and rapid thumping noise (almost as if the air compressor is kickin on?). At this point the motor will then fall back to 700 and idle normal. It will not do it again unless you release the parking brake and reapply. This ONLY happens when you set the yellow parking brake. Does not happen if I use trailer valve (red knob) to park. Does not happen if i drop to idle at a stop. Only when the yellow parking brake is engaged. This condition just suddenly started out of nowhere, nothing leading up to it. Other than that, everything else about the truck is aces. Starts, runs, pulls great! All temp/pressure gauges are normal. Any ideas anyone? Thank you
  21. Can anyone tell me the location for exhaust temp sending unit? 2011 CXU 613, MP8. I need the sending unit for the Pyro Guage on dash. Mine is going from 240 to 1250 degrees in sporadic flashes. Is it located in the dpf body? Thank you
  22. Absolutely, at least here in the Northeast, NJ, NY, PA. Freightliner reins dominate with Volvo a close 2nd. Good observation though 👍
  23. I can't get over the way the roof line cuts in so severely over the cab doors. Looks to me like it would be Niagara Falls upon entry and exit in the rain, nevermind ice and snow falling from there. Just looks almost as clumsy as the hood mirrors.
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