MP40 Acting Strange

Afrashz

Valuable Member
View Badges
Joined
Feb 23, 2018
Messages
1,222
Reaction score
879
Rating - 0%
0   0   0
For some reason lately my MP40 makes a loud clanking noise when coming out of feed mode into regular operation. Interestingly, if I manually take it out of feed mode via Mobius it does not seem to have this problem or if I turn the pump off and on it does not have this problem. The only time it seems to have this issues is when I put it in feed mode and 10 minute timer runs out and it returns to full speed. I took the wet side apart and all seems normal, no debris, no deformation.

Any thoughts?
 

Euphyllia098

Well-Known Member
View Badges
Joined
Dec 18, 2020
Messages
557
Reaction score
490
Location
Coldwater
Rating - 0%
0   0   0
Physically unplugging the power and plugging it back in. I've had some weird things in the past on startup that were fixed after unplugging it. Just pushing the power button on the controller doesn't seem to do the same thing. Not saying it'll fix it, but it's easy enough to try.
 

Waters

"...in perfect isolation, here behind my wall."
View Badges
Joined
Nov 5, 2013
Messages
9,349
Reaction score
20,857
Location
Mentor, OH
Rating - 0%
0   0   0
I would also take the wetside out and pop off the cover (three plastic clips). You might be able to see something out of whack inside.
 
OP
OP
Afrashz

Afrashz

Valuable Member
View Badges
Joined
Feb 23, 2018
Messages
1,222
Reaction score
879
Rating - 0%
0   0   0
Physically unplugging the power and plugging it back in. I've had some weird things in the past on startup that were fixed after unplugging it. Just pushing the power button on the controller doesn't seem to do the same thing. Not saying it'll fix it, but it's easy enough to try.
Thanks for the advice I’ll give it a try
 
OP
OP
Afrashz

Afrashz

Valuable Member
View Badges
Joined
Feb 23, 2018
Messages
1,222
Reaction score
879
Rating - 0%
0   0   0
I would also take the wetside out and pop off the cover (three plastic clips). You might be able to see something out of whack inside.
Yes I’ve done this and no issues from what I can tell. No debris and the center shaft does not seem to have any bends, cracks or misalignments
 
OP
OP
Afrashz

Afrashz

Valuable Member
View Badges
Joined
Feb 23, 2018
Messages
1,222
Reaction score
879
Rating - 0%
0   0   0
I normally don't use feed mode but tested my four MP40s just now and didn't hear anything abnormal when they returned to normal speed.
Thanks for checking, you don’t have any issues with food going everywhere with them on full speed?
 

GinaAlan

New Member
View Badges
Joined
Mar 2, 2026
Messages
2
Reaction score
1
Location
Berlin, Germany
Rating - 0%
0   0   0
For some reason lately my MP40 makes a loud clanking noise when coming out of feed mode into regular operation. Interestingly, if I manually take it out of feed mode via Mobius it does not seem to have this problem or if I turn the pump off and on it does not have this problem. The only time it seems to have this issues is when I put it in feed mode and 10 minute timer runs out and it returns to full speed. I took the wet side apart and all seems normal, no debris, no deformation.

Any thoughts?

From my experience with MP40s, a clanking noise like that often comes from the motor or rotor adjusting too quickly after feed mode. When the timer ends, the sudden jump to full speed can cause a brief mechanical strain, even if nothing is visibly damaged.

One way to check is to slowly ramp the pump back to full speed after feed mode using the Mobius app and see if the noise persists. If it stops, it’s likely just normal mechanical stress from the sudden speed change.

Also, make sure the pump is level and securely mounted, as slight tilts can amplify noises during sudden acceleration.
 
OP
OP
Afrashz

Afrashz

Valuable Member
View Badges
Joined
Feb 23, 2018
Messages
1,222
Reaction score
879
Rating - 0%
0   0   0
For some reason lately my MP40 makes a loud clanking noise when coming out of feed mode into regular operation. Interestingly, if I manually take it out of feed mode via Mobius it does not seem to have this problem or if I turn the pump off and on it does not have this problem. The only time it seems to have this issues is when I put it in feed mode and 10 minute timer runs out and it returns to full speed. I took the wet side apart and all seems normal, no debris, no deformation.

Any thoughts?

From my experience with MP40s, a clanking noise like that often comes from the motor or rotor adjusting too quickly after feed mode. When the timer ends, the sudden jump to full speed can cause a brief mechanical strain, even if nothing is visibly damaged.

One way to check is to slowly ramp the pump back to full speed after feed mode using the Mobius app and see if the noise persists. If it stops, it’s likely just normal mechanical stress from the sudden speed change.

Also, make sure the pump is level and securely mounted, as slight tilts can amplify noises during sudden acceleration.
Is there a way to adjust the ramp up speed in Mobius?
 

GinaAlan

New Member
View Badges
Joined
Mar 2, 2026
Messages
2
Reaction score
1
Location
Berlin, Germany
Rating - 0%
0   0   0
Is there a way to adjust the ramp up speed in Mobius?

Not directly, unfortunately. Mobius doesn’t have a separate setting just for ramp-up speed after Feed Mode, it automatically returns to whatever schedule and intensity you have programmed.

What you can try instead is:

• Lowering the maximum intensity in your schedule slightly to see if the noise reduces.
• Using a mode with smoother transitions (like Lagoon or Reef Crest) instead of something that jumps quickly in output.
• Or manually increasing the speed gradually in the app after Feed Mode ends to test whether it’s the sudden jump causing the clank.

If the noise only happens with the automatic return but not when you ramp it up manually, that points more toward mechanical stress from the abrupt acceleration.
 

TOP 10 Trending Threads

WHAT AMOUNT OF LIVE ROCK AND SAND SHOULD BE PRIORITIZED FOR OPTIMAL BIODIVERSITY/FILTRATION?

  • 100% live rock + bagged sand

    Votes: 37 27.8%
  • 100% dry rock + 100% live sand

    Votes: 45 33.8%
  • 50/50 live/dry rock, 50/50 live/bagged sand

    Votes: 29 21.8%
  • 75% live rock, 25% live sand

    Votes: 12 9.0%
  • 25% live rock, 75% live sand

    Votes: 10 7.5%
Back
Top