What's that noise?

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Came back from a head gasket job (milled head) a few weeks ago. Today while coming home from work, I noticed noise and rattle from under the hood. I could hear it from the cabin.



I though I had forgotten a tool under the hood but it wasn't, it seems to be from the belt area.

What could it be?
 
Take the belt off and run it, then you'll know if it's the engine or one of the belt driven accessories.
 
I agree with everyone, take off the belt to isolate the noise. Sounds like maybe it is coming from the timing area, but hard to tell on a video.
 
Sounds like timing belt tensioner/idler noises to me...

To be safe, don't run any more than absolutely necessary until you get this sorted out.
 
Based on this noise, is it safe to drive it to the mechanic that rebuild my car 60 miles away? Or should I tow it there?

Or should I bring it to a local mechanic to diagnose, and ask for reimbursement if it is the rebuilding mechanic's fault? (i.e. if he didn't tension the belt right or if he didn't rebuild the engine right)?
 
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Based on the noise I wouldn't drive it around the block until you have a better idea of what's going on.

Remove the accessory belt and see if the noise persists. If it does, then make arrangements with the guy that did the work and have him tow it back and fix it.
 
Call mechanic and ask him if it should be towed .. please let us know results
 
Originally Posted By: The_Eric
Based on the noise I wouldn't drive it around the block until you have a better idea of what's going on.

Remove the accessory belt and see if the noise persists. If it does, then make arrangements with the guy that did the work and have him tow it back and fix it.


+1

Always harder to tell over the internet, but I'd bet on a timing belt/valve train issue. Something's not quite put together right.
 
So the mechanic took the belts out, and according to him it turns out to be the water pump making these noises. He is charging me $75 for just the part price.

The pump was installed 70k miles ago, and in theory should last 1 timing belt interval (90k miles).

I though pump weep or make whining noise instead of suddenly start rattling like that.
 
Good to hear you found the problem- and no, they don't always weep or make whining noises first. Sometimes the first indicator is sudden and complete failure.
 
Can changing timing belt or prior overheating cause a sudden and complete failure? I am puzzled why it fail suddenly after a rebuild.
 
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Originally Posted By: PandaBear
Can changing timing belt or prior overheating cause a sudden and complete failure? I am puzzled why it fail suddenly after a rebuild.


Short answer: yes it can. Simply moving the tensioner around can mess it up if it's worn just so into position.

Seriously, all that work warranted some new parts. Does the water pump drive off the timing belt or is it outside the cover?
 
Yes it is driven off timing belt. You wouldn't believe what happened yesterday when I went to pick up the car.

I drove a beater that has a cooling fan / relay issue up to pick up this car. Right after I ask AAA to tow the beater back home for me, and started driving this car down, in the middle of the freeway it threw an AC belt (3:30pm). It split along the circumferential and shred / flap all over the engine bay. AAA towing back to my mechanic (5:00pm) and he replaced all the accessory belts (they are new ones that he put on) and I left his shop at 8:30pm.

The accessory belts were new ones the mechanic put on, the one that split were Contitech, made in UK in 2013 and has sort of waffle like outside texture. The shred belt got jammed into the other 2 accessory belts and to be safe the mechanic send me on a part run to a local O'Reiley for a new belt.

This is the first time I see how this mechanic work in person. He pile up lots of parts in the middle of the waiting area for all the cars, and he picked out my old belt to match the new one he "think" is for my car instead of checking the part number ahead of time (by the length of the belt), and realized during installation that he missed 1 belt (the shred AC belt). He also lost an inner fender screw and just pull one out of his part draw (10mm) instead of really look for it, and when he finished cleaning up his tools he didn't realized he missed a socket in the driveway (he was closing his shop and was fixing mine in the driveway with an overhead florescent tube hanging on my car's hood) until I picked it up off the ground for him. I hope this is not his usual habit, but he seems sloppy to me and to be honest I think I'd not let him touch my car ever again.
 
It was an AC Delco made in Japan one (probably a rebrand GMB) and even the mechanic says it is a high quality one and was puzzling why it failed so early. I suspect the mechanic I used to do the belt last time may have used silicate coolant that causes premature failure, or the radiator cap failure causes air in the head and may be what broke the pump.

The car is now much quieter than before, so I think the pump may have a bad bearing for a while and gradually got louder. I though it was some valve or exhaust noise but after the pump is replaced, I'm convinced that it was the pump bearing all along.
 
Watching mechanic work on the car is like watching how sausages are made; you really don't want to watch them!

Seriously, most mechanics do not (can not?) spend the time to do everything right. Well, at least I can't recall anybody who does it for the living.
 
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