Well, I feel a little like Jeff Foxworthy with this line...but ya'll ain't gonna believe this sh--!

The machine shop called me today and the machinist admitted he was wrong about the noise. Is is NOT a rod knock. So, all of you guys including ME who thought it was not a rod knock are vindicated. He said he found bird seed; yes, you are reading this correctly. BIRD SEED in the oil pan, oil pump pickup, and in the number 2 cylinder. There was evidence that something in the cylinder got compressed when the engine turned over, dislodging the oil ring from it's landing and scraping the cylinder wall pretty good.

Apparently, over the years as the engine sat, some critter (probably a mouse) had taken residence in the cylinder. I don't know how he got in there because I had plugs in it and the intake and exhaust ports taped off. It will cost me about $500 to replace the one piston and ring assembly and reassemble it, OR about twice that to bore the block and completely rebuild the bottom end with new pistons, rings, cam bearings, crank assembly, heads, etc. I'm leaning toward having the whole thing done and be done with it...never in my wildest nightmares did I expect to find something like this.

It is no wonder we could not figure out what the noise was but hey it was sort of fun trying anyway...

Vern

 

Vern,

Holy Cow!! birdseed?? who would have thought?? There are some things you just can't account for.

Being the tightwad that I am, and being that the rest of the engine is low miles I think I would opt for just replacing the one piston and cleaning up the one cylinder.

I am glad that you found something definate!!
Bobby

 

OK, that's one for the books! I'm surprised tho that seed didn't burn up from the combustion heat or get pounded into a powder. How did it get all the way into the oil pan? Maybe there was some gravel or something harder in the mix?
I saw pix of the damage done when a guy acidently knocked a box of BBs off a shelf into his intake while working on his engine!
Sure the rebuilder wasn't smoking something with seeds in it when it was reassembled?

 

Man 9 pages and it turns out to be bird seed go figure.

 

Vern did you have normal oil pressure reading on the gauge, I never thought to ask when we were talking lifters.

Rod 51F1

 

Ummm... how could birdseed get past the rings and into the pan??? I don't see how it could dislodge a ring, either. Maybe got behind the oil ring, behind the expander? Hard to believe. This isn't the same machine shop that did the original rebuild, is it? I'm thinking something was wrong when originally rebuilt, as little as you've run it since then, to do this much damage.

 

What a crazy tale you can now tell!
Just out of curiosity.....since something was compressed hard enough to knock the ring off the piston.......do you suppose you might have a little buddy still left in the exhaust system????
Ed

 

Actually, bird seed was my next guess at the problem LOL... Its not unusual for mechanics to bring their hamsters to work while rebuilding engines. Doesn't surprise me though, mice can get into anything and make a nest. I agree, this is one for the books. But..... I'm glad my diagnosis of it not being a rod knock was correct. Makes me feel good. LOL...

 

I too call shanangans! Mice would not just store birdseed in the cylinder had they been able to even get in there, but would have built a nest. When the engine started you would have had burning debris blowing out the exhaust. It especially wouldn't have broken the oil ring without the compression rings showing damage since it would have to get past them first. the ring gap is much smaller than any seed. Sorry, I don't buy the seed story.

 

OK Vern, I'll buy the seed story but I'm pretty skeptical like several others have already stated. Maybe there were two locations for the stashing of the bird seed. (#2 cylinder via the intake and the oil galley via the valve cover) Possible...yes, so let's say that's what caused it and tell this story for years. As far as your machinist, I would have been really impressed if he would have initially listened to the noise and said, "You know Vern, a lot of people would guess rod knock, but I'm sure that it's bird seed." I'm glad you got a handle on the problem, Jag

 

Ax,

Apparently, the critter(s) living in it carried birdseed all over within the engine including to the oil pan. I don't think it got past the rings and into the pan but I suppose there are passages within the engine the mice could have squeezed through once inside or as Jag suggested there might have been multiple locations where the mice were storing the birdseed. I had a bag of birdseed in the same garage where the engine was stored so the mice were probably carrying it in there for storage. Oil pressure was great though. Actually, there may have been debris blown out the exhaust when I first fired it up but I work alone and was at the front of the truck not the rear so I would not have seen it. One other item that I have not mentioned is that when I first put the new plugs in and fired it up it was missing. I later pulled the number 2 plug and the gap was closed. I chalked it up to stupidity on my part thinking I had dropped the plug or forgot to gap it. I re-gapped it and it was okay after that. However, in retrospect I think spmething was in that cylinder and it got pushed up into the plug and closed the gap up. I am going to go by the machine shop and look at the engine today.

Ed,

No, I hope I have no other little buddies left in the exhaust system. If so, I am sure they are crispy critters now.

Vern

 

I spoke with a good friend of mine yesterday who builds racing engines for a living. I told him the story of our little friend. He said if this truly occurred, it would be one in a million chances that the mouse made a home in the cylinder. He stated that if the mouse, etc was that determined to get into the cylinder to make a nest, he would of had to enter through the carb. pass through the carb plate butterfly (if it were open?) enter into the manifold to the heads where he would have to magically squeeze past the valve and seat, then enter the cylinder. Then, whats to say he can perform this same task to make trips back and forth to the birdseed? No way will a mouse cause a ring to break or come off. If there were a mouse, even a baby mouse in the cylinder, upon start up, it was smash him and at most make an furry impression on the piston head. Very unlikely he would be blown through the exhaust port into the exhaust. He could of entered thru the exhaust system but would still have to pass the exhaust valves. Why wouldn't he just make a nest in the muffler? He said if this mouse actually was able to enter the cylinder and make a nest, this mouse should be entered into the Rippley's Believe it or not! LOL... So, here's my evaluation of what happened. The mouse did enter the carb, did go into the manifold where he made his home. When you started the engine, his home and maybe the mouse got sucked into the cylinder along with the home and birdseeds gathered in the intake manifold. That would also explain how some birdseed was in the oil pan. Either way, this engine had to be moving to open passages. That would make sense to me. Maybe look in the manifold and see if there is a nest still stuck in there. Highly unlikely, but worth a look. One thing for sure, no cat is going to mess with this mouse!

 

Vern had the truck been sitting for awhile, is it possible the nest could have been in the air cleaner or carb and sucked into the engine when you started it. The chances of the critter getting into that cylinder sure seem strange to me also. In my 50 plus years I have heard a few strange things happening in engines, but this one tops the list for sure.

Rod 51F1

 

I still don't see how any of this would account for seed in the oil pan? The intake passages nor the exhaust are connected to the pan except past the pistons. That would have to be a VERY skinny mouse! Even if the engine were old enough to have a crankcase breathing tube (PCV came along before the 350 CSB AFAIK) no self respecting mouse would would want an oil filled swimming pool for a home or storage closet.
Please take LOTS of pix of this one!

 

I got it!!!

Maybe Ol' Vern, in a state of one too many frosty beverages, got the wild idea that bird seed would make a great dessicant and filled the oil pan before he put the engine in storage.....

...now he has to make up this wild mouse story as a cover up.

Come on Vern, fess up

Bobby