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Rebuilt my engine, now have a loud tapping noise.

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atruepretense

10+ Year Contributor
166
1
Jul 15, 2009
Bethlehem, Pennsylvania
That's not rod knock. Sounds to me like you left somthing or dropped somthing in one of the cylinders when the head was off. When you rev it up the noise changes and flutters abit depending on where the piece is or how it happend to get "squished" that particular time. I would pull all your plugs and look down into the cylinders with a scope, (you should see some shiney spots on the piston) if this is the case.

I've seen this at my shop a few times and pulled many heads to remove peoples fu&k ups. In one case i even found a wing nut off the air cleaner smashing around a cylinder but being to big to pass the exhaust valve.

That's just my 2 cents worth, since i'm certain it's not rod knock and doesn't sound like a lifter.

See, I thought that too. I took off the valve cover and looked EVERYWHERE for a loose rocker or bolt or something, I even shined a light into the cylinder and looked around for something but saw nothing. I was meaning to go to the auto parts store and get one of those magnetic extend pen things that would fit down into the cylinder. They have one at my auto parts store that is on a bendable stick so that would be awesome to find anything. I'll have to get that too. If it ends up being that, i'm gonna smack myself with a brick for being so stupid LOL. :banghead:

Yep, valve cover, head, oil pan and block, work top to bottom it should help you pinpoint the area, done it before tons of times when I was working as a tech.

Okay will do along with my now long list of things to check :p :rocks:
 
So I went to my car and pulled each spark plug at a time after the car warmed up, none of the cylinders got quieter, or went away. So not rod knock i'm guessing.

Would a valve cause this noise? I'm doing a lifter job tomorrow.
 
Well the fact that you didn't bleed the lifters tells you it's probably a lifter issue. It's pretty well known you must bleed the lifters before reassembling and starting it up.

If you really are unsure, just buy used lifters. New ones are not very expensive. Yeah it sucks pulling the head off and timing belt and all, but that's the choice you made when you chose to cut corners and not follow the proper procedure: the lifters must be primed and bled via a paperclip per VFAQ. I used that guide and had no problems. It does take a while for the lifters to fill with oil upon startup BTW, probably about 50 miles or so.

It's almost easier to replace lifters than to pull the oil pan on an AWD anyway. You can replace the lifters with the head still on anyway come to think about it, so do that first.

Glad to hear your doing the lifter replacement tomorrow; there's no use asking everyone to guess and troubleshoot until after you have reported back on the lifter job. Just remember; there's no use doing anything unless you do it correctly, otherwise you are wasting time and money.
 
thats pretty loud, it sounds like what my buddy had when he had a rod knock
 
Well the fact that you didn't bleed the lifters tells you it's probably a lifter issue. It's pretty well known you must bleed the lifters before reassembling and starting it up.

If you really are unsure, just buy used lifters. New ones are not very expensive. Yeah it sucks pulling the head off and timing belt and all, but that's the choice you made when you chose to cut corners and not follow the proper procedure: the lifters must be primed and bled via a paperclip per VFAQ. I used that guide and had no problems. It does take a while for the lifters to fill with oil upon startup BTW, probably about 50 miles or so.

It's almost easier to replace lifters than to pull the oil pan on an AWD anyway. You can replace the lifters with the head still on anyway come to think about it, so do that first.

Glad to hear your doing the lifter replacement tomorrow; there's no use asking everyone to guess and troubleshoot until after you have reported back on the lifter job. Just remember; there's no use doing anything unless you do it correctly, otherwise you are wasting time and money.

Well I've bled the lifters, now I just need time to actually go put them in. The reason I keep asking and troubleshooting was because I was getting so many conflicting answers, both here and in person. Some said rods, some said lifters, others said something in the timing belt area, some said Bshaft bearing, so I was going crazy haha. I'll let you guys know the outcome.

The only thing you have to take off is the valve cover when changing lifters.

YouTube - 4G63 Lifter installation without special tool part 2

Goddamn it, i've been taking off the cams and TBelt. FML. Thanks for telling me this bro. haha.
 
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