I just bought an '83 pickup and there was noise coming from the block, when I dropped the oil pan I found about six pieces of plastic about 2"-3" long.
Does anyone have any idea what that might be from?

 

Probably from the plastic timing chain guide. time for a new timing chain etc.
check with ted at http://www.engnbldr.com/

 

Lets see some pics of them if possible.

Years ago I was adjusting valves on my service pickup with a 22r, and accidently dropped my feeler gauge. That damn thing went right down one of the oil return holes into the pan.
I always wondered if anyone ever found that gauge years later.
Funny how crap finds it's way into those engines.
When I replaced the engine in my 94' 4runner, I was cleaning out the oil cooler and found a couple pieces of broken taillight lens in the coolent side of it. Wierd stuff.

 

your engine is making noise you say ???

I would guess your t/c guides as well , The noise is now the chain slapping up against the cover .. It will soon wear a hole in it , if it hasnt already .

 

Only one thing

I thought the 83 had the dual row timing chain that does NOT have plastic guides...

 

NOPE ... it is convertable to a double chain ! .. but the 81 , 82 and 83 and up -> has the single chain and plastic guides .

 

Ah - thanks for the clarification...

Later blocks like the 22RE are also convertable but for alot more money
-- custom chain
-- machined front cover
(LC Engineering Kit)

The dual chain uses metal backed guides....

 

Yep, snapped timing chain guides

 

Can you clarify? I have seen some sites that say that the '81 have dual row and metal-backed guides. IIRC, my '81 does have the dual row, but I have never seen the guides. Even if they are metal-backed, they still have plastic bits that wear through and fall into oil plan, right? The difference is that now the chain is riding on the metal backing instead of the timing cover if you have the metal backing. Once you clean the bits out of the pan, it should be safe to run the motor without the plastic parts of the tensioner as long as it has a metal backing, right?

 

OK, I checked last night. My '81 has dual row chain, metal-backed chain guides. My dad bought the truck in '84 with 20k on it. So unless it had a timing chain issue before then, that should be original timing gear. My chain has worn all the way through the plastic on the driver's side guide, but the metal is now guiding it. I guess this accounts for the rattle on startup. I couldn't get the oilpan off to save my life, but the guides didn't look like they broke apart, just wore through, so I think the oilpan will be fine. I will find out (hopefully) this weekend when I pull the motor and take a bigger coaxing wrench to the oilpan while it is on a stand.