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2.6 loud whirring noise after valve job and IAC soak (video)

1K views 10 replies 4 participants last post by  DSUZU 
#1 ·
Crossposting this since I don't think as many people read my build thread and I got to figure this out soon before a camping trip I have planned

I adjusted the valves (.008 intake and exhaust) and also soaked the iac tube in pb blaster overnight. Turned the truck on today after 24 hours of soaking, white puff of smoke out the exhaust for a few seconds, then noticed that the truck has a loud whine. Sounds like a supercharger. Not sure what's going on, I took a video.



I disconnected the smog pump belt since I originally thought that's around where the sound was coming from, no change. Removed the cam cover to see if it would be louder, no change. Really seems to be coming from under the valve cover. What could I possibly have done wrong?

Thanks
 
#2 ·
Couldn't really tell anything from the sound in the video. Really shouldn't be anything under the valve cover to make a whirring sound. Possible alternator, water pump, or idler bearing? You can get a long screwdriver or rod, place one end against the component (alt, etc) and the other against your ear and locate sound or bad bearings that way. They also make mechanics stethoscopes for this. Dennis
 
#3 ·
Yeah I tried the long screwdriver trick and couldn't really pinpoint it up top, everything just sounded like engine vibrations. Didnt try the alternator since it's so far down there but tested the charge at 14.0v

Next time I'm at the truck I'll take a picture of the IAC line I soaked just to make sure it was the right one. Ill also try a few more spots with the screwdriver trick

I guess the sound almost sounds normal on video, but theres a really loud whirring tone to the point where my friend could hear it from his own car when I was driving behind him. Kind of similar to a car driving in reverse
 
#5 ·
Attached the file of the iac.

Thought I heard it on the power steering pump with a screwdriver and removed the belt, no change.

With an open ear i *think* it's most prominent at the main pulley where the fan and a couple belts mount to (not sure the name of it). Ive spilled power steering fluid here in this area before. Tried lubing behind it with no luck
 

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#6 ·
DSUZU said:
Couldn't really tell anything from the sound in the video. Really shouldn't be anything under the valve cover to make a whirring sound. Possible alternator, water pump, or idler bearing? You can get a long screwdriver or rod, place one end against the component (alt, etc) and the other against your ear and locate sound or bad bearings that way. They also make mechanics stethoscopes for this. Dennis
My dad taught me that trick using a piece of dowel many years ago. I thought he was pulling my leg just to see if I would do it Lol.

That definitely does not sound like mine at all but have no clue as to what it might be.
 
#7 ·
I think I'm onto something. I noticed spraying silicon lube behind that pulley and on the fan clutch bearing and taking it for a spin *seems* to make it just slightly quieter each time. I repeated this cycle almost ten times this morning and now the noise is nearly inaudible while driving behind all the other engine noise. I can still hear it clearly when under the hood and revving it, but this seems like progress. I feel like I can drive down the street without people staring now haha

What's the official name of this part? Water pump pulley? Fan Pulley? Can't find it on parts websites and I feel like I should bring a backup with me on my trip just in case.
 

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#8 ·
Fan clutch. Dennis
 
#11 ·
That'd be the water pump. Try wiggling the fan (with engine off of course). Dennis
 
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