Help to identify engine noise (video)

VR777 · #1 07-17-2016, 05:29 AM

Hello,
Could you, please, help me to identify this noise? It happens only between idle and 1000/1300 RPM. Sounds like loose chain to me. What should I check/replace first?

https://youtu.be/Vc8igNlDacc

Noise is clear from 1:15... and watch in 1080p for better sound
BMW E53 2006 3.0i 78k miles

X53Jay4.8is · #2 07-17-2016, 10:26 AM

Sounds like a chain rattle indeed. Perhaps the chain tensioner is going. You don't have high miles so I would start with the simple stuff first.

bcredliner · #3 07-17-2016, 02:16 PM

I wouldn't replace anything yet. Still more troubleshooting to do. I would start by using an auto stethoscope to try to pinpoint the source.

Does it make the noise both when it is a cold start and when the engine is at operating temp? Is it louder at one or the other?
Is this something that started all of a sudden or has become progressively worse over time?
Are the belts in good working order and tight?
Are you losing any coolant over time?
Are there any other symptoms?

VR777 · #4 07-17-2016, 02:58 PM

thanks for reply, guys. First time I have noticed this was about year ago or so. Didn't pay much attention since everyone say that M54 is noisy from factory. Sound got louder and is more noticeable when car is hot and when I tap accelerator like in the video. Dealer had a look, but they said that engine sounds fine to them. Belts are fine, no coolant or oil loss.
Tomorrow I will go and get tensioner piston for the start. I will write once I change it and if there will be any change.

VR777 · #5 08-28-2016, 09:32 AM

so... Finally I have replaced the tensioner. Sound became a bit more quiet but still present. what should I check next?

Eric Giles · #6 08-28-2016, 09:58 AM

It's always tough to diagnose an issue remotely, but my first thought is that this might be a slight Vanos rattle. With the engine running, put your hand on the front of the engine directly on top of the Vanos area. Have someone else rev the engine. If you feel a vibration directly under your hand and if the sound seems to be coming from the top area, then that's most likely the problem. Besian Systems sells a Vanos seal and anti-rattle kit to take care of this issue.

Then again, it may be something as simple as a failing idler or belt tensioner pulley.

bcredliner · #7 08-28-2016, 11:11 AM

Need to see if you can pinpoint the location source. Is the sound there all the time cold or warm engine?

VR777 · #8 08-29-2016, 01:29 AM

Quote:

Originally Posted by Eric Giles

It's always tough to diagnose an issue remotely, but my first thought is that this might be a slight Vanos rattle. With the engine running, put your hand on the front of the engine directly on top of the Vanos area. Have someone else rev the engine. If you feel a vibration directly under your hand and if the sound seems to be coming from the top area, then that's most likely the problem. Besian Systems sells a Vanos seal and anti-rattle kit to take care of this issue.

Then again, it may be something as simple as a failing idler or belt tensioner pulley.

I also thought about VANOS, but shouldn't it make more of a knocking sound? I will check it also

Quote:

Originally Posted by bcredliner

Need to see if you can pinpoint the location source. Is the sound there all the time cold or warm engine?

No sound during cold starts and gets louder once it warms up. After long drive it becomes quite noticeable

bcredliner · #9 08-29-2016, 02:24 PM

Not time to buy parts, is Time for an auto stethoscope to see if you can narrow down the source of the noise.

VR777 · #10 08-30-2016, 01:53 AM

Quote:

Originally Posted by bcredliner

Not time to buy parts, is Time for an auto stethoscope to see if you can narrow down the source of the noise.

I will try to find one and will write result