Engine tapping

[Birdman71]

Just got the VR-4 from the transmission shop (rebuild std) and put about 500 miles on her when driving on highway little over speed limit a loud tapping noise is coming from the engine compartment. Stopped driving it immediatley. All gauges read normal. The noise seems to be coming from the drivers top side of the engine and follows RPM. I removed the oil pan and everything looks great. I removed the head covers same thing. Checked all spark plugs and compression, checked timing and belt, ok. I understand how far a noise can travel so I'm wondering if there is a tranny problem? Any thoughts?
Thanks

[Igovert500]

Are you sure it isn't just lifter tick? It sounds like a time bomb...there is a section in the FAQ about it. Our cars are infamous for having it.

[Birdman71]

Its definetly not ticking. I can almost duplicate the noise with a hammer. Can a lifter become that bad.
Thanks

[YogsVR4]

If its not lifter tick, then it could be rod knock. The first is an annoyance, the other is bad news.

[StealthModifier]

he said he pulled off the oil pan. he could of been able to tell it that way whether or not it was rod knock.

[Twizted_3KGT]

ooo I know...your flywheel is loose. Happened to me before, sounded like a hammer smashing that stayed w/ RPM's. Couldnt pinpoint it until I took a stethascope to it and found it coming from flywheel. By ear it almost sounds like it's your camshafts knocking. I'd suggest taking it back and having them take the tranny back off and make sure everything is fine. I mean that's not all it could be, but that's what happened to me before.

[YogsVR4]

Originally Posted by StealthModifier

he said he pulled off the oil pan.

oops next time I read twice

[Linebckr49]

let's hope it just a loose flywheel. my friend had his 454 72 Chevelle motor rebuilt 6 times this summer b/c the guy obviously didn't know his stuff, and also b/c he spun a few bearings in there. i don't think a spun bearing would make a knocking sound, but whatever it is, they just rebuilt it, so you make them fix it.

[StealthModifier]

Originally Posted by Linebckr49

let's hope it just a loose flywheel. my friend had his 454 72 Chevelle motor rebuilt 6 times this summer b/c the guy obviously didn't know his stuff, and also b/c he spun a few bearings in there. i don't think a spun bearing would make a knocking sound, but whatever it is, they just rebuilt it, so you make them fix it.

A spun bearing makes a pretty loud knock actually. When it idles it knocks kinda randomly but once the rpms get higher it knocks very fast an steady.

[Linebckr49]

intersting. thanks Modifier, i didn't know that. but that makes me worry even more about Birdman's engine now.

[StealthModifier]

yea sounds like what he described.. sounds like taking a smaller hammer and tapping it on a piece of metal. but if it was a spun bearing he would of known by pulling off the oil pan an seeing if any of the rods were loose.

[Birdman71]

VR4 update,
After inspecting all I could with the oil pan off head covers off I refilled with fluids and thought I would start it up to investigate location of noise, Once started the tapping noise wasnt so loud as before,
If at all like a lifter tap. Wasnt always there, the more the car warmed up the louder and more instense it got. Once in a while the noise would change to an loose, growling, rolling sound. The noise is more pronouced from the topend driverside of the engine. So this sound translates to $$$$$.
Going to have to find a reputable mechanic because this is going beyond my expertise.

[Twizted_3KGT]

Well now id say it was a spun bearing...but could still be flywheel loose. Since they're right next to eachother you can't really tell by ear.