Metallic grinding noise at 1900rpm from engine

NaweedM

NaweedM

Member
 Eindhoven NL
Need some help 🙁

As my zed is reaching 300,000Km's, a metallic grinding noise popped up all of a sudden. I can 100% replicate it every time if i hold the revs at 1900RPM. Any tips on where to look? Should I stop driving?

So far I can already eliminate the transmission and clutch as the noise occurs in neutral and with the engine disconnected from the transmission.

Below I have posted 2 videos, one from outside and one from the cabin






When I tried to locate the noise with my ears, I can hear it quite well around here. From the cabin it sounds central. Any tips would be greatly appreciated!
1780155828046.png
 
Something i can try and see from the engine bay or does it require a lift + undertray removal?
 
Pop it up and get a friend to press the accelerator. You’ll see very quickly
 
Whilst I can't help with your problem sadly, I can say that I have a vibration @1900 rpm also. Rear silencer is the culprit (I think).

Wonder why 1900rpm though?
 
CuppaTea said:
Whilst I can't help with your problem sadly, I can say that I have a vibration @1900 rpm also. Rear silencer is the culprit (I think).

Wonder why 1900rpm though?
Click to expand...
Chances are the vibration of the engine is just right to cause resonance at those revs. It may do it at other revs but you may not hear it as other noises could be drowning it out.

I have a slight steering wheel wobble at exactly 45-48mph. No other speed, ever. Same sort of mystery.
 
Thanks @bigwinn
I will locate this part and do some poking around with a wooden stick to see if it changes the frequency. Was getting worried it was something from the VANOS system, but I watched a few youtube videos and noticed it has a different rattle frequency.

I have an M54, the manifold should look like this, right?
1780179619208.png
What numbered part should I look out for?
 
Last edited:
Found the root cause to the rattle. Luckily it isn't anything major

Need some expert advice on this part. Can i just remove this and call it a day? Also do let me know if my exhaust flange looks bad, it doesn't look like I have any bolts holding it in place...
20260606_153823.jpg

What is the purpose of this? stops the flange from hitting each other i would assume? If it is important, I can replace it as its not in a difficult spot
1780768232961.png
 
NaweedM said:
Found the root cause to the rattle. Luckily it isn't anything major

Need some expert advice on this part. Can i just remove this and call it a day? Also do let me know if my exhaust flange looks bad, it doesn't look like I have any bolts holding it in place...
View attachment 295545

What is the purpose of this? stops the flange from hitting each other i would assume? If it is important, I can replace it as its not in a difficult spot
View attachment 295546
Click to expand...
Holy cow I was right

I need to tell the missus
 
The picture you shared threw me off when I was looking but the text you wrote pointed me to the exact location. Definitely helped me! Was easy to see without the car being on stands. Also silenced the noise by applying pressure with the end of my flashlight. Unfortunately I now have a melted flashlight as I forgot exhaust pipes are hot. :rofl:
 
Your in for a fight with those exhaust flange studs, they are not bolts and very difficult to get out, been through this twice once on a 2.5 and lately on a 2.0l. Go and have a look at the post I made when I fixed the 2.5 to see whats involved.
colb

Thread '2.5 Exhaust Downpipe joint rusty bolts replaced'

The exhaust bolts on the downpipe joints had corroded away what was left of the two lower nuts were just about holding the joint together and of course the rust. The original bolts have blind splined heads that grip inside the upper joint holes and were seized in. Cut what was left of the lower end of the bolt so it was flush with the exhaust flange and gave the air hammer a go but it wouldn't shift the bolt. Ended up using a thin cutting disc in the angle grinder and cut a slot along lower and upper sides of the jointing brackets which took the tension off the splined end. A few rattles...

The metal ties that attach to the studs help to reduce the resonance that is generated buy the vibrations in the pipes so they really need to be retained.
 
You must log in or register to reply here.
Back
Top Bottom