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Discussion Starter #1
Can anyone point me in the right direction on this issue?

My N62 has developed a whine/drone that seems to be coming from the passenger side. I removed the main accessory belt and the noise was still present. I didn't want to remove the AC belt because it is a stretch belt, but the noise does not sound like it is coming from the AC compressor - besides the noise is still present when I turn the AC off.

Other posts suggest the Secondary Air Pump - but the noise remains even after several minutes on idle/periodic revving.

Recent work I have done:
- Drivers Side TC cover gasket, VC gasket, Alternator bracket gasket.

Recent issues:
  • flickering low pressure light (I think i have a small leak around the pressure switch, so that is next)
  • various and sporadic timing codes


 

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Michael
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It is proportionate to the revs increasing, I would have thought it also sounded fan like, have you got a mechanics stethoscope?? excellent tool for finding idlers or pumps etc with dodgy bearings.
 

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Discussion Starter #5
It is proportionate to the revs increasing, I would have thought it also sounded fan like, have you got a mechanics stethoscope?? excellent tool for finding idlers or pumps etc with dodgy bearings.
that’s what I initially thought it was - the fan grabbing a loose wire or a piece of tape. Initially I only heard it on startup, but now it’s whenever I rev the engine.

I don’t have one at the moment. I fear a trip to the tool supply is needed.
 

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There is always a whine when the car is at a cold state, until the engine is in closed loop. When the engine is in open loop, the engine runs on a preset baseline, until the O2 sensors tell the DME the engine is warm. The SA system only runs for less than 1 minute, so rule that out. To me it sounds like a vacuum leak, most likely from on of the CCV vent tubes. They will usually stall a engine, but they crack very easily when removing them doing VC gaskets. Did the engine have this sound before the repair work? I have heard that sound, I just can't remember where it was from? If you disconnect the cooling fan, that can be ruled out. It is something sucking air, smoke test time.
 

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Discussion Starter #7
There is always a whine when the car is at a cold state, until the engine is in closed loop. When the engine is in open loop, the engine runs on a preset baseline, until the O2 sensors tell the DME the engine is warm. The SA system only runs for less than 1 minute, so rule that out. To me it sounds like a vacuum leak, most likely from on of the CCV vent tubes. They will usually stall a engine, but they crack very easily when removing them doing VC gaskets. Did the engine have this sound before the repair work? I have heard that sound, I just can't remember where it was from? If you disconnect the cooling fan, that can be ruled out. It is something sucking air, smoke test time.
I will say, I disconnected the drivers side CCV vent tube as I was confirming proper solenoid installation - and since then, the noise has gotten worse.

herb, do you think if I replaced a cracked tube, the noise would go away?
 

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If you have a cracked tube, yes. Our engines running heavy vacuum, especially at the intake.
 

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Discussion Starter #10
Okay, I found a couple vacuum leaks using a Cigar test at the intake:

one seems to be coming from the grommet on the driver side valve cover nearest to the Eccentric shaft sensor. Perhaps the eccentric shaft sensor itself?

the other seems to be coming from the intake cam shaft sensor on the passenger side.

these seem like strange places to be having a vacuum leak.

thoughts?
 

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The Eccentric shaft seal usually goes after a while, & will usually cause a lean condition on that bank. I always change these when the VC's come off. The o-ring on the sensor can be found at Home Depot or Lowes. The vent tube might not leak until warm, do a visual inspection. I hate even touching one in fear of it cracking! How did you apply 3 psi with a cigar? You don't want to use much more than that. My smoke tester below works very well, & has gone up in price I see.

 

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Discussion Starter #12
The Eccentric shaft seal usually goes after a while, & will usually cause a lean condition on that bank. I always change these when the VC's come off. The o-ring on the sensor can be found at Home Depot or Lowes. The vent tube might not leak until warm, do a visual inspection. I hate even touching one in fear of it cracking! How did you apply 3 psi with a cigar? You don't want to use much more than that. My smoke tester below works very well, & has gone up in price I see.

I am thinking eccentric shaft sensor seal as well. I will try to replace those.

I pulled plastic cellophane wrap over the air intake duct after the MAF sensor, stuck a Harbor Freight fluid transfer pump through the cellophane and taped it to seal it. then I stuck the cigar on the other end of the HF pump. Definitely no more than 3 psi.

Very similar to This video .

I would be able to see a cracked tube on visual inspection? How noticeable will the crack be? Also, would I still be having this issue on startup if the temp is affecting it?

I started it up to test, and I will say the noise lessened as the engine heated up today.
 

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I would remove the pipe to inspect it very closely, as the crack might not suck air until the engine has a load on it. You can spray starting fluid around the pipe to see if the idle will change. If the idle changes any where on the pipe or any area close to the pipe, the idle should increase. Also inspect where the intake silencer pipe clamps on the TB, as they will also crack with time. I guess the smoke test on the video will work, it just want supply as much smoke as a smoke tester under load.
 
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