[rome92]

Help, I’ve recently encounter this crazy knocking sound on my e92 and I’m clueless on what could be the problem! I recently swapped the fuel injector #3 because I had a misfire issue. The car ran perfectly after I swapped it out but now I’m hearing a crazy rattle.
Here is how it sounds:
https://www.reddit.com/r/BMWN5x/comm...t=1&utm_term=1

Please comment what you think it could be or what should I look into

[TSilver335i]

Originally Posted by rome92

Help, I’ve recently encounter this crazy knocking sound on my e92 and I’m clueless on what could be the problem! I recently swapped the fuel injector #3 because I had a misfire issue. The car ran perfectly after I swapped it out but now I’m hearing a crazy rattle.
Here is how it sounds:
https://www.reddit.com/r/BMWN5x/comm...t=1&utm_term=1

Please comment what you think it could be or what should I look into

Sounds like Rod bearings. I wouldn't drive it to avoid further damage.

Edit: On second listen it could be faulty injector. Where did you get the one you replaced?

does it get louder with throttle input?

[Dynamics99]

I had the same sound. It sounded like it was coming from the top front valve cover but it was my rod bearings. It was my fault when changing the bearings and not torquing the Cylinder 1-rod cap properly. The engine ended up shooting the cylinder 1-rod cap through the oil pan. At least it failed in my driveway. It's weird that the crankshaft is smooth on the bottom but I have to check it on the top for score marks. If it is scored then I will have the crankshaft set to accept oversized bearings.

Probably try to pull the motor this weekend and assess the damage for a rebuild but most likely will be going with forged rods and pistons.

I wouldn't run the car if I were you. Drop the subframe and oil pan. Drop the pickup tube and check for side-to-side play on each bearing. Drop the oil pump if you can't check the bearing play for Cylinder 1.

If you have play then pull the bearings and pray your crankshaft aint scored. If it's scored you may be able to get grinded down and use oversized bearings.

To pull the crankshaft you would have to pull the motor.

[whyzee125]

Yet another N55 bites the dust. I can't believe there are still people out there who swear they don't have RB issues. Sorry to hear it OP

[friedymeister]

Have you figured it out?