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Discussion Starter #1
B5.5 2.8. I changed all the pulleys and belts less than 2 years ago and it's only been driven like 10k miles or less. Could this be a bad bearing in the aux fan? All other tensioners and pulleys were changed except the alternator's but the sound is too high. It feels like it's right under the engine cover. Will have to wait until daylight and warmer temps to check. Any risk in driving it?
 

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The Aux (electric) Fan only runs if either the A/C is turned on or the engine needs extra cooling. If you have Climatronic, you may need to switch it to Econ mode, but that should switch the electric fan off this time of year. That should help to narrow things down.
 

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Discussion Starter #3
The Aux (electric) Fan only runs if either the A/C is turned on or the engine needs extra cooling. If you have Climatronic, you may need to switch it to Econ mode, but that should switch the electric fan off this time of year. That should help to narrow things down.
My mistake, I meant the viscous fan.
 

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Discussion Starter #5 (Edited)
A little nervous it's coming from inside the driver's side cylinder head or under that side's timing cover. Could timing chains/cam adjusters do this? Ugh. I know I did everything right when I did the timing belt and have been trouble free since.
 

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My car does the exact same thing. I've been told it's the cam chain tensioner for the VVT among other things, not the engine timing.
 

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Step one: use a piece of strong tape between the rim of the mechanical fan and the radiator support to hold the fan from turning. Start the engine; if the noise is gone, then the problem is the viscous fan bearing. If not:

Step two: release tension on the serp belt and slip if off of a pulley, such as the PS pump. Start the engine; if noise is gone, search for culprit by turning each pulley (except crank pulley of course). If not:

Pull valve covers to inspect inspect cam chains.
 

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Discussion Starter #8
Step one: use a piece of strong tape between the rim of the mechanical fan and the radiator support to hold the fan from turning. Start the engine; if the noise is gone, then the problem is the viscous fan bearing. If not:

Step two: release tension on the serp belt and slip if off of a pulley, such as the PS pump. Start the engine; if noise is gone, search for culprit by turning each pulley (except crank pulley of course). If not:

Pull valve covers to inspect inspect cam chains.
Thank you. What would I be looking for under the valve cover? A loose/slack, hopping chain or cover? Would this mean my timing jumped a tooth?
Guessing I should park it until I have the time to do this? Am I risking catastrophic damage if it's a cam issue?
 

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The CCT isn't part of the engine timing (apart from the VVT), that's the belt. As far as I know, and someone else chime in on this, you shouldn't face any issue unless the noise gets noticeably louder.

Check out this video, it's one of my car. You'd know if your timing jumped. Immediately throws a CEL and the car won't run well at all.
 

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Discussion Starter #10
The CCT isn't part of the engine timing (apart from the VVT), that's the belt. As far as I know, and someone else chime in on this, you shouldn't face any issue unless the noise gets noticeably louder.

Check out this video, it's one of my car. You'd know if your timing jumped. Immediately throws a CEL and the car won't run well at all.

Ok, for some reason I remembered being very cautious about making sure the chain went right back where it was when changing the seals. My memory may be a little foggy. I never changed the crank seals because I had read they rarely leak and changing them can do more harm than good. It's possible I'm mixing up the write-ups and that's why I was concerned about timing.

I had always read that timing could be off a tooth without throwing a code and you would notice a difference in the driveability.

If it was a bad pulley or bearing after such a short period of time (and I remember reading about some issues with timing belt kits) then I'm running the risk of destroying the engine if it seizes correct?

You may have seen another post of mine where I was concerned about the tone of the engine recently. This is following that so I'm wondering if they could be connected somehow? The only code I have at the moment is p0441 which I used to solve by tightening the gas cap.

Anyway, I have some investigating to do. Hope it's just something simple that can be fixed by removing the serpentine belt.
 

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Discussion Starter #11
According to comments in this video, I should ot be driving it:

Sound is pretty darn similar. And I can't believe I'm going to have to re-do the timing belt again if it's a bad tensioner.
 

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Shut it down until you find out where the noise is coming from. While it's difficult to diagnose online, perhaps a video of the sound will help. Follow what ylwagon said to diagnose the noise.
 

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Discussion Starter #13
Shut it down until you find out where the noise is coming from. While it's difficult to diagnose online, perhaps a video of the sound will help. Follow what ylwagon said to diagnose the noise.
The mystery deepens...On my afternoon commute rattle was gone. Parked it at home, took the dog for a walk, just drove it again and no rattle. I'm too much of a pessimist to think it's gone for good though. If this helps narrow down a problem let me know.
 

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Usually I tell people a difficult to hear or intermittent noise will worsen to the point it is easy to diagnose. Not comforting, but generally true.
 

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Discussion Starter #15
Usually I tell people a difficult to hear or intermittent noise will worsen to the point it is easy to diagnose. Not comforting, but generally true.
Does anyone have a simple way for me to check behind the timing belt cover? I'm only going to drive it back to my house from my mom's where it's been parked but I want to confirm some things first.
 

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The upper timing belt covers can be un-clipped and removed for a better look and listen. You can also drive with them removed, although when done inspecting I would re-install them.
 

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Discussion Starter #17
The upper timing belt covers can be un-clipped and removed for a better look and listen. You can also drive with them removed, although when done inspecting I would re-install them.
Thanks, it's been a couple of years since I've been in there. Couldn't remember if the fan had to be pulled off first. I won't be able to see the tensioners though will I? That's my chief concern at this point. I've been reading a lot about failures from the ECS kit and it's usually the tensioners. If it does end up being an issue I hope I have some recourse with ECS Tuning- It's been less than 10K miles.
 

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I don't think you'll see enough of the tensioner to make an assessment, but its easy to give the belt a twist, at say the passenger side under the sprocket; should not go past 90 degrees, if that.
 

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Discussion Starter #19
I don't think you'll see enough of the tensioner to make an assessment, but its easy to give the belt a twist, at say the passenger side under the sprocket; should not go past 90 degrees, if that.

Took the covers off and checked for deflection this weekend-Nada. Drove the car this morning and the rattle does seem to have disappeared, I'll have to wait and see if it returns and then try to take a look/listen when I know it's there. How bad is it to drive with the covers off? Is the danger that a rock or pebble might jump up into the pulleys?

Couple of things I did notice: When I parked and revved the engine up to about 6000 rpms I would get a screech/squeal every time. Not sure if that's related to the noise I had been hearing.

Also noticed some smoke from an oil leak I had already fixed which has sprung again, so pretty bummed about that.
 

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How bad is it to drive with the covers off? Is the danger that a rock or pebble might jump up into the pulleys?
If you drive on gravel roads all day without a belly shield, it might be possible, but I doubt that there is actually much risk. But keeping dust and water away from the critical timing components is not a bad thing.
 
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