Mack 470 Ccrs low on power

[Scrubby veiw]

Hi all here in Aust have a trident with 470 Ccrs has serious power problems very sluggish down low in the revs if you could keep above 1500 isn’t so  bad . This has been ongoing for 2 years in that time has had a complete new crate motor installed only thing under the bonnet that hasn’t been replaced is the starter motor and alternator. Has made no difference to old motor so thinking sensor or something tried numerous mechanics and still driving a slow truck .Have a. Vision with same engine completely different engine to drive it has torque range from 1100 to 1700 any help would be appreciated 

[Joey Mack]

Are the engine computers in both trucks the same? If so, swap them.  I wonder if there is a programming issue?

[JoeH]

You change your wiring harness?

[Mackpro]

Does your 470 CCRS have a wastegated turbo? Over here in the states our 2001.5 to 2003.5 CCRS 460 had a wastegated turbo and was a royal pain to get it to run right . We detuned several to 427 and replaced the wastegate turbo with a standard 427 turbo and no issues. With the 460 CCRS  program over here, the engine ecm looks at the boost pressure sensor readings at different engine load, throttle pedal and other sensor readings and there is a narrow band of what the boost pressure readings would be. If the boost is not in the correct range then the engine pulls the fuel back and usually sets a fault code. When all was correct they ran great , if not then it was about like having. 300 or 350 hp. 

[Scrubby veiw]

Hi sorry for the late reply it does have a wastegated turbo the other truck blows black smoke every time you put your foot to the floor this one blows next to no smoke which to me says it’s a fuel problem have had all the so called Mack experts play with it changed ecm changed turbo on old motor three times nothing changes it’s like a 2 stroke moterbike just won’t pull down low even when you get it going it’s still a gear worse than the other one in the hills about 10-15 km per hour slower at 20 tonne in town you have to use all 18 gears to keep the revs up or it just stops

Edited June 1 by Scrubby veiw

[Scrubby veiw]

The vision boosts slightly higher about 24 this one only gets to 21-22

[Scrubby veiw]

Have suggested to mechanic to swap ecms in trucks he says not that simple has to reprogram  the truck computer to match ecm so I don’t know thought there might be a sensor somewhere or something sick of throwing money at have just been putting up with it last six months but it is giving me the shits it doesn’t bring any codes up

[JoeH]

One guy here just found a baffle plate clogging the inside of his muffler. And I forget, did you pressure test your CAC?

[Scrubby veiw]

Have just put a new muffler the last one was blocked solid but didn’t seem to improve it at all  but thanks 

[Mackpro]

Mack service bulletin SB-214-017 covers testing the testing the wastegate. It’s pretty detailed on testing and when it should be opening and staying closed. Be sure to pressure test the complete intake system.  Thoses years had paper intake manifold gaskets that were later changed to steel core gaskets due to blow outs. The air compressor can get its fresh air from the back of the intake manifold. This metal pipe and hoses can leak which leak boost pressure. Unit pumps and injectors are wear items and can weaken over time. 

[Scrubby veiw]

Thanks we have changed all hoses new intercooler new manifold new injectors three of the eups have been replaced due to slight leaks and bringing up faults it had steel manifold gaskets will have to check turbo watergate I’m sure the adjustment on the new turbo had a spot weld on it so it couldn’t move but will double check . Before we swapped the engine out we swapped the turbo made no difference then they put on a brand new wategate  because that was apparently the problem that made no difference nearly ready to throw petrol and matches at it

[Scrubby veiw]

Checked wastegate it has a spot of weld on the thread so it can’t be adjusted bought from local Mack dealer so not sure if it should have or not

[Joey Mack]

Is it weld or Dicum? Is it under warranty?

[Scrubby veiw]

[Scrubby veiw]

Looks like weld would still be under warranty 

[Scrubby veiw]

On 5/28/2024 at 9:10 PM, Joey Mack said:

Are the engine computers in both trucks the same? If so, swap them.  I wonder if there is a programming issue?

Hi just going back through old messages can I just swap the ecms if they are the same without causing any issues have been told that would have to reprogram the truck computer to match thanks

[Joey Mack]

The base program will run the truck. We used to swap ECM's often to try to diagnose issues. Make sure the key is off.

[Scrubby veiw]

No problem will give it a try thanks