B7500 Knocking

ferndezmond

New member

Equipment
B7500
Jun 4, 2025
1
0
1
Zebulon NC
New owner of a B7500 here. It starts up just fine, but sounds like it has a pretty loud knock. Fairly new to Diesels, so not sure if it is an injector or rod knock. To me it sounds like rod, but wanted to see if anyone more seasoned has an opinion.

For background it has been sitting for years. I replaced all the fluids and filters before running. I bled the fuel system at the injector caps and each one caused the motor to bog down slightly.

Link to video for sound
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
33,073
8,487
113
Sandpoint, ID
Sounds normal to me.
Crack the injector lines at the injectors while running.
If the speed drops the same on each but sounds stays the same, no problem.
If the speed drops and the knock drops on any one, there is an issue.