So I'm trying to get a car back on the road after sitting for 15 years and one thing that I did was pull the oil pan to reseal it since it was leaking. Once I got it off, I found a bunch of chunks of plastic in the bottom of the oil pan. This is on a 4 port 13b out of an RX-4. These are just a few of the chunks that I found. The larger one is the largest one that was in the pan and there were a bunch of ones like the smaller three. Any idea what these may have come from?

 

Old oil cap pieces?

 

You didn't give us a size reference.

My bro's RX-4 pan had a lot of charcoal chunks from the carcoal canister in the air cleaner lid. They got sucked through the line going to the intermediate plate and ended up in the pan. I was very disturbed when I didn't know what they were.

 

those definatly look like chunks from an oil cap. i've seen it in engines that i've torn down. its not common but it does happen.

 

Exactly, bottom part of the stock oil cap; the vertical ridges on the inside of the arc are a dead giveaway. This happens when some overtightens an old, brittle cap.

 

That definitely makes me feel better. I'm not particularly familiar with rotaries. This is my first one and it's actually in a VW Beetle, so I was a little worried that I was going to hear back that they were chunks of some kind of guide for something or other and it would need to be torn down. Thanks for the replies.

 

There is a plastic tensioner for the oil pump chain on older engines like from the '70s. But yeah those chunks look like oil cap. No need to worry about the tensioner. I've never seen one wear out.

 

Take the big piece and see if it matches up to the rim of the oil filler neck. Then you will rest assured.

 

oil cap filler parts breaking off?? should I replace my oil filler cap?

the plastic feels so aged and brittle

 

Probably a smart move; it's likely not sealing right if it's that far gone.