N55 - Whirring/screeching Noise. Rear Cranshaft Seal?

[alfredoporro]

Hello All,

After having my valve cover replaces as a warranty job because of a leak on the rear passenger side of the engine that was sending fumes into the cabin through the vents, a whirring/screeching noise started to be more loud when the car is at operating temperature. I heard the noise before the replacement of the valve cover but it was not as loud.

Right after replacing the valve cover, the mechanic heard the noise and after looking around the engine bay and under the car, he checked the area where the rear main seal is. While the car was running, he opened the oil engine cap and the sound stopped. He told me that the culprit is the RMS. He said he didn't see any oil leaking when he was inspecting that area and that for now it is only air passing through. He said that I should replace it but it doesn't have to be right away, probably when my next oil change is due.

When the engine is running after a cold start, I don't hear the sound but after driving the car and reaching operating temperature, the whirring/screeching noise can be heard.

There are no codes and the car runs normal. I connected MHD to rear codes and everything is clear. Right after the valve cover job, I drove the car 80 miles without stopping. I was told to check faults for the following and MHD came out clear:

"If it has camshaft timing faults it is bad Vanos Solenoids. Also make sure the oil filter cap has the center tube intact that holds the oil filter cartridge. If it has eccentric shaft faults, its a bad eccentric shaft sensor.
Both these issues cause the variable valve lift to go into failsafe which creates excessive crankcase vacuum. The whistling noise is from air rushing in through the front and rear main oil seals. Creates a whistling effect"

MHD report:

- DME active codes -
None

- Misc. information -
MHD build: version 1.8
Voltage 15.07V
Last flashed file : Unknown
Factory software: 7623266
Current software: 8684966
ECU status: Normal operation

- Readiness -
Misfire: Complete.
Fuel System: Complete.
Components: Complete.
Catalyst: Complete.
Heated Catalyst: Not avail.
Evaporative System: INCOMPLETE.
Secondary Air System: Not avail.
A/C Refrigerant: Not avail.
Oxygen Sensor: Complete.
Oxygen Sensor Heater: Complete.
EGR System: Complete.


I checked the oil filter cap and the center tube was intact in my opinion. Just in case I replaced the filter and the seals but this didn't make a difference.

I would like your opinion and see if anyone has had an issue like this here.

Videos where you can hear the sound, first one is engine running cold and the second is the engine running at operating temperature where you can hear the whirring/screeching noise (noise starts at the firs 3 seconds):

https://youtu.be/qa_D7iNUmT8

https://youtu.be/y_p7hEBkzgc

[yco]

nice amount of information given about the problem..

sounds and looks to me like a harmonic balancer/damper fail.. though wondering how much the noise change after applying some throttle.. or if the engine runs with a little more vibration that can be an easier signal for it as well..

but at the same since there was a leakage before it can be from any pulley as well.. if i were you, i d drive the car normally while listening engine and see if things go worse or better as long as you hear the noise only on idle..

[alfredoporro]

Originally Posted by yco

nice amount of information given about the problem..

sounds and looks to me like a harmonic balancer/damper fail.. though wondering how much the noise change after applying some throttle.. or if the engine runs with a little more vibration that can be an easier signal for it as well..

but at the same since there was a leakage before it can be from any pulley as well.. if i were you, i d drive the car normally while listening engine and see if things go worse or better as long as you hear the noise only on idle..

I try to give as much information as possible

I'll check the harmonic balancer, I just watched a video where you can hear the noise and see it wobbling. In this video, the noise is constant but in my car while the engine is cold I don't notice any noise. When my car warms up for a while or after driving and getting at operating temperature, then I hear the noise but it is not as constant as in the video I watched. Link to the video I'm talking about:

https://f30.bimmerpost.com/forums/sh....php?t=1164732

I know the AC tensioner had been replaced recently in my car with a BMW part. Right after the valve cover replacement, I drove 80 miles without stopping and the car run good (this was at the beginning of April). After that, I have only driven the car a couple of times, maybe like 20 miles or so.

Yesterday I drove it and I didn't notice anything unusual or any weird noise while driving it, normal idling and driving. I put my window down when I was driving at 40 MPH and nothing caught my attention. Once I was entering my carport I could hear the noise and then after I stopped the car, I recorded the video I linked in the first post.

[yco]

Originally Posted by alfredoporro

I try to give as much information as possible

I'll check the harmonic balancer, I just watched a video where you can hear the noise and see it wobbling. In this video, the noise is constant but in my car while the engine is cold I don't notice any noise. When my car warms up for a while or after driving and getting at operating temperature, then I hear the noise but it is not as constant as in the video I watched. Link to the video I'm talking about:

https://f30.bimmerpost.com/forums/sh....php?t=1164732

I know the AC tensioner had been replaced recently in my car with a BMW part. Right after the valve cover replacement, I drove 80 miles without stopping and the car run good (this was at the beginning of April). After that, I have only driven the car a couple of times, maybe like 20 miles or so.

Yesterday I drove it and I didn't notice anything unusual or any weird noise while driving it, normal idling and driving. I put my window down when I was driving at 40 MPH and nothing caught my attention. Once I was entering my carport I could hear the noise and then after I stopped the car, I recorded the video I linked in the first post.

its probably rpm related but it guess it gets lost with the engine sound.. have you tried it?
you can try really small rpm jumps to see if it changes.. as i ve said after a leakage it can be any pulley.. AC, alternator... you can try putting AC on and off to see if it makes changes.. and does the noise change when you turn the wheel all the way and creep like that?