E90Post
 


TNT Racewerks
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > N54 Knock Sound Help



Reply
 
Thread Tools Search this Thread
      06-18-2024, 09:31 AM   #1
Sprusinski
New Member
3
Rep
7
Posts

Drives: Lemans Blue E92 335i M-sport
Join Date: Aug 2023
Location: Grantsburg Wisconsin

iTrader: (0)

N54 Knock Sound Help

http://youtube.com/shorts/-yEsi5tkTBk?feature=share

Some background:
I just installed this used N54 from my parts car with 136k miles and bone stock originally. I thought the engine was sound after doing a compression test but it's making some sounds I don't like. When I removed the oil and had the pan off I didn't notice any excessive amounts of metal. Oil looked clean and pan was free of debris. I should've checked bearings but I didn't bother at the time.

The problem:
I'm trying to diagnose this knock. I've already tried removing the accessory belt but the sound didn't change. Could it possibly be the DMFL? It almost sounds like it's coming from there but it's hard to tell. The head sounds healthy to me as well. You can hear the sound clearly from the exhaust but I'm having a hard time pinpointing it.

What I need:
If anyone has insight on where to start with the knock it would be greatly appreciated. I already sent in an oil sample to Blackstone about two weeks ago so I'm eagerly awaiting their response. Is there any way to test for failed rod bearings without dropping the pan? I'm really hoping I don't have to pull this motor again

Thanks for your help
Appreciate 0
      06-19-2024, 04:01 AM   #2
Podunk
Private First Class
40
Rep
102
Posts

Drives: 335I E90
Join Date: Mar 2024
Location: MO

iTrader: (0)

Dual Mass Flywheel may be failing, or when mating to transmission something is off.

does the sound change at all with clutch pedal depression?
Appreciate 0
      06-20-2024, 11:33 AM   #3
Sprusinski
New Member
3
Rep
7
Posts

Drives: Lemans Blue E92 335i M-sport
Join Date: Aug 2023
Location: Grantsburg Wisconsin

iTrader: (0)

Solved:

Quote:
Originally Posted by Podunk View Post
Dual Mass Flywheel may be failing, or when mating to transmission something is off.

does the sound change at all with clutch pedal depression?
I was able to resolve the knock. It turned out to be a failing injector. The sound was getting amplified by the exhaust and with the help of a mechanics stethoscope I could pinpoint it
Appreciate 0
      06-23-2024, 07:33 AM   #4
Podunk
Private First Class
40
Rep
102
Posts

Drives: 335I E90
Join Date: Mar 2024
Location: MO

iTrader: (0)

Quote:
Originally Posted by Sprusinski View Post
I was able to resolve the knock. It turned out to be a failing injector. The sound was getting amplified by the exhaust and with the help of a mechanics stethoscope I could pinpoint it
Awesome, glad you figured it out.
Appreciate 0
Reply

Bookmarks

Tags
bearing, dmfl, help me, knock, n54


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 04:30 AM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST