[JamesO93]

Hi guys,

Please bare with me here as I’ve only owned this car for a week and 2 days so I’m incredibly new to the BMW World.

I have a 2011 E92 335d M Sport with 130k on the clock, the car has full service history (with receipts to prove) using Miller Oils from Opie Oils, so I know the maintenance of the car has been great however I have an issue.

On cold start the engine sounds awful. Sounds alot like rod knock, however the second you touch the throttle it disappears, this noise will continue on idle until the engine is upto operating temperature then it goes away. This is really only an issue when the car has sat over night.

The fact that when you rev the engine it instantly stops calms me a little in thinking it can’t be anything serious however the noise is still pretty concerning, I saved up for a long time to get myself the car I always wanted (335d e92) and hearing this sound is certainly concerning.

I have a video from my Ring Doorbell but it makes it sound 100000x worse than what it actually is so I’ll try and get a proper video to upload.

The thing that takes me away from rod bearings is the fact when revved it disappears and when warm it’s completely silent (albeit normal diesel sounds)

Anyone had this issue or know of this issue?

[JamesO93]

https://youtube.com/shorts/1TkkKNBG1UM?feature=share

This is the sound, the car had been sitting for roughly 2/3 hours prior to making this video, it’s louder when it’s stone cold but when it’s warm it’s quieter/goes away almost

[lnxguy]

Welcome to your first BMW diesel. That doesn't sound anything like rod knock. I'd worry less and drive more.

[JamesO93]

Originally Posted by lnxguy

Welcome to your first BMW diesel. That doesn't sound anything like rod knock. I'd worry less and drive more.

Please see this video. This is how it sounds (even louder when it’s been left overnight)

https://youtube.com/shorts/2oDWQiCvN0Y?feature=share

Once warm it’s quiet, may not be rod knock but it doesn’t sound healthy!

[nonford]

Sounds like a cold start diesel to me...

[B58]

Worse case scenario it’s just a minor fuel knock. Could be from an injector or injectors or the fuel pump. Mine did the same. Just got louder over time and cylinder #2 and I think #4 injector threw a fault code with a rough idle. Swapped in 6 Bosch injectors and it idles and sounds much quieter in the mornings.

[JamesO93]

Just to update this thread it was infact the crank pulley (Harmonic Balancer) which failed a couple of weeks ago, power steering went heavy and burning rubber smell, only with the AC on, switched the ac off and pulley was moving again.

Replaced pulley had no belts in stock at my local MF so replaced pulley and put old (in great condition) belts back on for now, a day later the aircon belt shredded itself (doh)

Belts are being replaced once they arrive but the issue is now fixed