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2016 CHU613 Power issues


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Really hoping someone can help me solve this problem because I've lost faith in my Mack dealer and we have dumped A LOT of money into this truck already! I'll try to give as much information as possible but if I miss something feel free to ask.

Truck is a 2016 CHU613 with an MP8 505HP 18spd. We bought the truck 5 months ago with just over 100,000 mi. The truck was a repo unit owned by a local bank and was set to go to auction but we ended up buying it before that happened. 

Now the problem, truck has what seems to be a good amount of power in low range, but in high range (or at highways speeds) you can mash the pedal and the truck won't move out of it's own way. On a fairly good size incline at 65mph with an empty 48ft flatbed, the truck can't even maintain it's speed, let alone accelerate. My 05 Pinacle with an 18spd will accelerate up the same hill pulling a 40,000 lb load. The truck idles smooth and runs great at low speeds, checked the boost gauge yesterday on local roads and its showing around 33psi at full throttle

This truck has been to the dealer twice, it had some minor oil leaks and they replaced a bunch of gaskets (not quite sure which ones because our shop mechanic has the write up) and they've replaced all of the injectors and injector cups. They also said the truck may have been "derated" because the EATS was throwing fault codes and the truck was not going into regen. After many failed attempts by the dealer, they were able to finally force a regen, but the performance is the same.

We are at almost $20,000 in dealer charges and the truck still has no top end power! I'm at a loss, and we've dumped so much money into this paperweight that getting rid of it is not an option.

To date we have pulled 4 loads with this truck, PLEASE HELP!

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  • 3 weeks later...

Took it to the dealer yet again. Here's what I've gathered....the truck has an "econodyne" tune. When I asked them to tune it to "maxidyne" the lead tech said it probably wouldn't make much difference. But they've been playing with this truck for so long that even they want to figure out what's going on with the truck, so the tech went for a ride along with me. I had a 48' flatbed with about 5,000lbs loaded on the deck (essentially empty) got on the highway and right away he noticed that the truck was incredibly slow. His computer was telling him that the truck was only putting out 67% power and wouldn't hit anything over 1300 lb-ft pounds of torque at wide open throttle pushing about 25psi. Drove around with him for 45 mins up and down hills, highway, back roads, the works.

Got back to the dealership and he updated the software on the truck. He also pulled up the programming and told me the "econodyne" tune has 4 settings, 0-1-2-3. The truck was set at 2, so he changed it to 0. He said "it probably wont fix the issue, but try it and let me know either way". So I left the dealer and as soon as I got on the highway, i noticed a significant difference. I was able to pull much harder on inclines and the boost gauge was getting up to 40psi at full throttle, even the throttle response was significantly different. 

Here's my problem,  I'm still having a hard time up the hills with 20,000 lb loads, and I truly feel it's a tuning issue, but they keep telling me they'd hate to have me spend the $3,000+ to re-tune the truck because they dont think it would change much. We pull upwards of 100,000lbs consistently,  and I'm afraid this truck isn't going to handle that kind of weight... thoughts?

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This here is some decent info thanks for posting it ! Having said that this here statement says a lot ( I was able to pull much harder on inclines and the boost gauge was getting up to 40psi) 40 psi is a good boost number  ! If you are maintaining that on the pull or close to that, IN my opinion your getting most of what you paided for!

I for one would like to know what part of  the program he was able to gain access to set the fuel numbers portions of the perimeters ! they are are usually only accessed by headquarters and u usually have to pay to get it!

So if anyone here has that knowledge please pipe up!

👍

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How he did what he did is way above the knowledge I have, but as far as getting what I paid for, I still feel like this thing is not giving me full power. My old truck (05 Mack CXU with 600,000+ on the clock, also an 18 spd) will out pull this truck any day as will our KW's with a Cummins 450 and a 10 speed. Put it this way, if this is all the power this truck has, that's a sad state of affairs and it should not be a "heavy spec" truck. I would love to have this thing tuned to "maxidyne" with no restrictions and see what it can really do, but everyone keeps telling me it won't change much. If it wont change much, why would it even be offered???

https://www.macktrucks.com/powertrain-and-suspensions/engines/mp8/

Here's the link to the mack website with the torque specs (if you scroll down and click on "econodyne" with the 505) you'll see standard torque numbers, and "econoboost" torque specs which is only offered in the M Drive (as far as I know) which my truck has the Eaton 18spd. The "maxidyne" gives you the full power output. Am I missing something? How would this not help the power issue if everything else is checking out perfectly fine?

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Don't see anything helpful on that link.

Does your truck feel like it follows the econdyne torque curve?

Does the maxidyne torque curve look better for your application? If so, is that change in torque curve worth $3000?

 

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It would be worth $3,000 hands down if I knew for sure it would fix my power issue. And judging by the difference I saw from just changing the parameters on the current tune, now I'm leaning towards that being the problem

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When I had the tech on the ride along with me, he said the truck would hit 1300 lb-ft torque and just stop abruptly, wouldn't go past 1300 at all, which was unusual to him because with a power loss, the torque reading would typically fluctuate,  even if it wasn't by much, but my truck wasn't doing that. It honestly feels like the pedal and the truck want to do so much more but something isn't allowing it to. Does anyone know the process in changing the tune? What makes it cost so much? Do they need to change other things as well or just the programming? 

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I would have dragged him along after he set it to 0 mode on the econdyne.  Why would he monitor it, change it, and not monitor the change? Give you raw data to see what changed and what didn't?

Only thing I could think of for cost variable is the engineer time to design the fuel map. But you already paid for a 505 with a fuel map, it seems stupid to me for them to charge you 3k because you picked a fuel map that you don't like. I wonder if you could pick up a used maxidyne ECU for cheap. Wonder if it'd conflict with everything else, truck miles, vin, etc.

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Problem is, I didn't pick this truck with this fuel map, a bunch of idiots who sit at a desk all day did, and we bought it used so there wasn't much of a choice there. But it was purchased with the intention of being used as a heavy hauler to move our crane houses and big loads of steel, and right now, this truck has a hard time moving a deck set of empty trailers. So with this current configuration we can't use this truck for its intended purposes. I just wish I knew if it would make a big difference or if the difference would be marginal 

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59 minutes ago, JoeH said:

I would have dragged him along after he set it to 0 mode on the econdyne.  Why would he monitor it, change it, and not monitor the change? Give you raw data to see what changed and what didn't?

Only thing I could think of for cost variable is the engineer time to design the fuel map. But you already paid for a 505 with a fuel map, it seems stupid to me for them to charge you 3k because you picked a fuel map that you don't like. I wonder if you could pick up a used maxidyne ECU for cheap. Wonder if it'd conflict with everything else, truck miles, vin, etc.

Correct The truck will pick up on an ecu mismatch! I agree the guy needed to test out his work!

Not achieving the torque of even a 425     1450- 1850

 

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