• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Thunking noise coming from front end and loss of power


New member
Apr 1, 2024
So i recently replaced my fuel injectors, fuel pressure regulator, out tank fuel pump and filter; which was a nightmare because i was having a fuel leak coming from the banjo bolt on the pressured fuel line that took forever to fix. Theres still a very tiny leak but i thought it wouldnt make a much of a impact. But since then my volvo has had a drastic loss of power, like i can barely get over 30 mph sometimes, and when i try to accelerate i hear a distinct thunk sound coming from the front end drivers side, she hickups and then accelerates a bit.

The loss of power im thinking is because something is restricting fuel flow, so i could be a faulty fuel pump, faulty injector, air in the fuel lines or it could be because i had to gerry rig the main fuel line because the bolt attaching it to the pump was seized and i had to cut it off and then get some tubing and attach that to the fuel line with some hose clamps (stupid i know lol).

But none of that would explain the thunk sound, it could be my suspension but that wouldn’t explain why the sound occurs when im accelerating. Maybe the brake motor? Or the transmission (god forbid)?

Im taking her to a shop to have someone more competent than i take a look next week but i thought i would ask here aswell
The thunk could be a broken motor mount and the loss of power might be a torn intake hose that opens up when the motor lifts from the broken mount.
May or may not be a great test, my engine rocked a lot under load even with "good" new mounts...

One could also apply light lifting pressure to the engine with a jack (padded) or lifting bar and see if the mounts allow it and/or start to separate.
The way to check motor mounts is to power brake the car. It's easier with an auto but it can be done with a manual trans too.