Why does my cam move side to side so far..& bang?

[Paisley]

Well it's side to side in a transverse mounting. Front to back in standard.

I picked up a 3.4 out of a '95 Camaro in hopes it could get me by for a while. But rotating it yielded a metal contact noise for every full cam rotation. I kept spinning it and noticed that when it makes the noise the cam moves forward maybe a 1/4". So I side-loaded one of the lobes and the cam moved to a point where it sounded like it contacted the back of the timing cover. Dropping the pan I found two items. One is a black plastic cylinder about 1" long and .64" in diameter with a metal sleeve inside it. There was also a small black plastic wheel with a 1" stem on it that dropped out too. I think a bird stole the wheel. He was sitting there when I came out of the house and I noticed it was gone shortly after. I got as far as pulling the timing cover and found a little stretch but nothing horrid. All the oil was just black. No frothing anywhere.

Any ideas why the cam walks so far?
Any idea what the black plastic devices were?

I'm hoping to get 20,000 to 25,000 miles on this engine. Any help would be appreciated.

[Paisley]

The cam timing gear is definitely contacting the timing cover. There's a fresh grind mark found in it when I took it off. What keeps the cam from moving?

[1988GTU]

manual or auto? Did you check the oil pump drive gear for wear?

[Paisley]

Auto car. I didn't check the oil pump for wear. I understand the oil pump, but fairly newb. Look for wear patterns? Check it for slop? Check side clearances to body and cover?

[caffeine]

The gear on the oil pump drive (where the distributor used to be) is a place I would check

[Paisley]

Okay, thanks. The engine is getting a distributor, so the metal plug is coming out if the engine checks out good enough. Should I just go for pulling that plug first to check? Does that gear you mention hold the cam from walking?

[caffeine]

I'm not sure how large of a roll it plays but with the oil pump drive gear in place, the cam cannot be removed out the front.

[geoffinbc]

Are you turning the engine clockwise? The shape of the lobes on the cam and the pull of the gears that drive the pump are all that keep the cam gear against the thrust surface of the block.

[Paisley]

Yes, turning clockwise is when the engine performed that maneuver. Is that the correct direction? I found that the timing tensioner had some pieces broken off of it. The general shape was still present, but it has been whittled on by the chain I assume.

[Paisley]

ETA: The cam is out. Just needed a running start to clear. Front cam bearing is roached from the broken cam sensor.

Also, the lobes have normal shape, but the wear...each lift and return has a wear pattern off the side of the lobe. It's identical on each lobe for lift and and return.

I tried removing the cam, but something blocks removal at the last cam main. The cam is completely out with only the gear and rear main left inside. The gear comes through the front bearing but something is preventing the rear cam main from clearing through the bearing.

Is this common? How does it come out?

[geoffinbc]

It should come right out of the block. You just need to pull straight with a little twist and wiggle. If the front 3 journals came out then the back one should unless something has damaged it