Valvetrain noise! Metal against Metal!!!

Hi. I'm new to OHV motors and this is the first time I've made an attempt to work on one so please forgive me if I sound like an idiot. Ok, I've been trying to diagnose a sound that has been coming from the topend of my motor for the past week. Here are the details,

When I start my car and let it warm up at an idle, the motor will Not make any abnormal noises. After its warm, if I take it for an easy drive, it will not show any symtoms of a problem. Once I get on the throttle, however, I begin to notice a noise that sounds like Metal to Metal contact but it is very random almost like a piece of metal is shooting around underneath a valvecover. If I bring my car to an idle again after I get on it, it keeps making the sound. The last time this happened, I got out of my car quickly, felt around my valvecover on the passenger side, and found that I could feel as if something were hitting the cover. Thinking to myself that I had found the source to my problem, I removed the valvecover and found no markings from contact with a rocker arm. Everything appeared to be in good shape (nothing broken, nothing loose). Frustrated, I removed my intake manifold to look for signs of a bad lifter. This is where I stopped. My first question is, do I have to remove each lifter to check for signs of damage? My second question is, can a lifter make this kind of noise? I'm beginning to think that I'm missing the obvious. Can someone please give me an idea of what could be making this sound? Thanx and some mods are listed below.

*1989 Mazda RX7*
late model 5.0 block
fully ported '69 351w heads
Forged silv-o-lite keith black flattop pistons
Scorpion roller rockers
crane double valve springs
crane hydraulic roller lifters
lunati hydraulic roller cam
edlebrock rpm intake manifold
Holley 650 DP
MSD 6AL ignition
MSD distributor
Tremec 600 tko tranny
King Cobra clutch

Half broken in what way? Did you notice any kind of movement that there shouldnt have been? Thanx for the fast reply.

Nevermind, sorry. Anyone else have any ideas. Thanx.

KDK1988GT said:

and u did not find anything inside the valve cover?

Check and look for some small piece... something like a valve lock could have cracked/let go.....

U running the stock valve covers? Has this problem just started? Is this a new motor combo ??

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No, i can't find any pieces of anything inside the valve cover. The springs dont appear to be broken and no nuts are missing or loose (including the poly-locks inside the nuts). The sound is definately coming from somewhere in the valvetrain on either cylinder #1 or #2. So, I'm thinking about removing those four rockers and looking for damage on the under side of them. Does this sound like it should be my next step? I'm a little hesitant because i've never taken a motor like this apart before. Also, I have Aftermarket Moroso valve covers and the motor has approx. 15k on it. Thanx.

could be as simple as an exhaust leak..they can sound very simular to mechanical noise.

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I wish it was. I actually just fixed an exhaust leak I had at the header about a week ago. And your right, it did sound like a mechanical noise but it sounded more like the *tick* a bad lifter would make.

Well, I found my problem but I have no idea what caused it. A mangled lifter was making the noise. Please check out the pics below:

http://img2.freeimagehosting.net/image.php?4439573561.jpg

http://img2.freeimagehosting.net/image.php?1888a881b3.jpg

http://img2.freeimagehosting.net/image.php?071fea432c.jpg

I've thinking about this for the past half hour or so and the best guess I could come up with is that the bearing on the roller must have locked up somehow. It looks like the lobe on the cam wore a large groove into the roller. I was also thinking that it could have been caused be piston to valve contact but I would think a pushrod or valve would break before a lifter. Anyone have any input?

Yeah, I know I have to replace the cam because it wore a groove on the lobe but I was unaware that it would be necessary to tear the motor down. I was thinking that I would replace the cam and lifters (all just to be safe). Then I would remove the oilpan and clean that out to get rid of any metal fragments. Does anyone else have anymore input?

Just another thought because I'm not 100% sure but if I have metal shavings in the motor as a result of this, wouldn't they just be in the oilpan and oil filter. There isn't anyway they could have worked there way any further like into the oil pump, is there? Thanx everyone for your input.