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Please check your rod cap torque before shipping engines to retailers. DOM 4/29/19-yes it was a Monday build. Thought for sure the PO failed to put oil in this engine. Engine looks brand new including cylinder wall! Pulled cover off bottom and saw the rod bearing, rod cap, crankshaft and bearing were clearly destroyed. First rod cap bolt I removed (top/first photo) was barely finger tight. Other rod cap bolt appeared properly torqued.

Before you start blaming Briggs I would do a few more checks. In pic #2 and #3 I can definitely see metal transfer, which is an indication of overheating. A loose rod bolt can be caused by lack of lubrication, which will cause overheating. I’m not saying that the bolt was not tightened properly, but your pics indicate there might be over problems.

A loose rod cap bolt without other factors will not transfer aluminum. Rod and crank both show aluminum transfer which says lack of oil at time of start and run.

If it was a problem being a loose rod bolts considering how of these engine are produce each year the dealers would be filing a lot warranty claims. To me it look more like a case of an engine being ran with very low level or no oil. It only take a few minutes with no oil to start this transfer process.

There have been no dealer service bulletins issued by Briggs for a problem like loose rod bolts.

Going through the APSIs, CSBs, DSBs, and SBs I see only one recently that covered the 09P series. It in reference to a leaking valve cover on serial number range 20080100 - 20092800.

No dog in this but had a customer being in a push mower last summer with a briggs engine said it had 2 hours on it and it just stopped. Pulled the rope and no compression. Put a screwdriver down the sparkplug hole and piston not moving. Told him to call the mfgr about warranty. He picked it up and took it to another shop he was told to take it to. He said he got a call that the rid cap came loose and crank and rod was toast and he got a new mower free.

I’ve got no dog in this question, and we don’t know the reason Briggs granted warranty to your customer. I just know from my limited experience, 99% of the time when I’ve seen metal transfer like in the pictures posted, no warranty due to overheating caused by lack of lubrication. 95% of the time I agree with them, while the other 5% I’ve disassembled the engine and found enough dark oil to question their assessment. Getting warranty in these cases most of the time will depend on your experience dealing with the claims specialist.

I'd ask the owner if he mows on any inclines. Oil slinger in good shape?

The only way you get metal transfer is not having oil between the two surfaces
This causes excessive heat which can stretch a bolt making it look like the bolt was loose from the start
Now if the bearing is on a pressure fed crank then you can get metal to metal contact but it would be very rare for metal transfer
What usually happens id the cap breaks and you get hammer marks in the journals .

So without having it in my hands I would concur with the others, most likely run with low oil .
However unless you pulled it out of the box yourself there is always the chance that some idiot has fired it up before you got your hands on it .

Brand new engine low on oil? Cylinder wall is very nice-oil starvation would have a cylinder wall scratched quite badly too, sorry low oil theory just doesn't fly. Can anyone go to a retailer and start pulling dipsticks and see how many are low on oil when pushed away from a retailer? If you want to simply disagree for the sake of disagreeing go ahead. One loose rod bolt caused this...piss and moan all you want to.

They aren't pissing and moaning.
They're looking at pictures, and using their gathered knowledge of small engine repair and how they work and how they fail to list possible causes.
They don't have it right in front of them like you do.
what I don't like is when people come here, post something, and are shocked that they get a different answer that disagrees with what they've already determined was the cause of an issue.

if you are so sure it is a warranty failure due to a loose rod bolt, you might as well finish tearing the engine down, You will need pictures of all three crankshaft bearing surfaces, the crank rod bearing surface, the wrist pin, the piston, the cylinder walls, the flywheel bearing surface area in the block, the pto bearing surface in the engine sump, pictures of the camshaft bearings and the top and bottom bearing surfaces in the block and engine sump.

Any bearing damage to those other bearing surfaces will get warranty denied. Since this engine is almost 2 years from DOM what is the purchase date meaning how long has the person owned the engine.

Dust is from being in storage for several months. This engine did not mow a yard: https://postimg.cc/gallery/Lhz5pbQ

The Push mower said:

Brand new engine low on oil? Cylinder wall is very nice-oil starvation would have a cylinder wall scratched quite badly too, sorry low oil theory just doesn't fly. Can anyone go to a retailer and start pulling dipsticks and see how many are low on oil when pushed away from a retailer? If you want to simply disagree for the sake of disagreeing go ahead. One loose rod bolt caused this...piss and moan all you want to.

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Hmmm, How would explain the one I got a couple years ago the threw the rod through the crankcase. It didn't have any cylinder scratches but rod journal was coated with aluminum. On top of that the crankshaft and blade were bent. Customer only ran it 30 minutes or less per him. Walmart refunded him his money but they shouldn't have done it as it was definitely abused.

If you are a Briggs dealer and you think it under warranty then as IL suggest done the rest of the tear down and file a claim. But I am fairly certain it will get denied.

For being a no dealer I can't even get a local dealer to replace defective new parts that I get from my Briggs distributor. I even warranty new Briggs engines out my own pocket when I sold the engine.

I was just offering my opinion as I don't care one way or the other about the problem just what caused the problem which is aluminum transfer causing the joint to over heat.

The Push mower said:

Brand new engine low on oil? Cylinder wall is very nice-oil starvation would have a cylinder wall scratched quite badly too, sorry low oil theory just doesn't fly. Can anyone go to a retailer and start pulling dipsticks and see how many are low on oil when pushed away from a retailer? If you want to simply disagree for the sake of disagreeing go ahead. One loose rod bolt caused this...piss and moan all you want to.

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The loose rod cap isn't the cause of failure. the loose rod cap is secondary to the crank journal overheating due to lack of lubrication. And you can have crank/rod damage without cylinder damage. Have seen it several times with a no oil start out of the box. Heck even had a couple with failed crank/rod bearings that were sitting on the box store display. Cause of failure was customers would walk by and crank the mower over without oil in the engine. The cranking over by just pulling the rope is enough to cause metal transfer.

Rivets said:

I’ve got no dog in this question, and we don’t know the reason Briggs granted warranty to your customer. I just know from my limited experience, 99% of the time when I’ve seen metal transfer like in the pictures posted, no warranty due to overheating caused by lack of lubrication. 95% of the time I agree with them, while the other 5% I’ve disassembled the engine and found enough dark oil to question their assessment. Getting warranty in these cases most of the time will depend on your experience dealing with the claims specialist.

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I have no idea if it was low on oil while he ran it but it was full when he brought it to me. I know the shop he took it to that does warranty work. He called me to let me know that they told him the rod bolts came loose and that either MTD or Briggs, i don't know which, would replace it with a new mower. I have seen my share of seized engines that customers added fresh oil to before they brought it to me. I have done work on other things for the guy and i don't think he is that kind of a guy. I don't do warranty work on any brand so i am not an expert on how it works.

The OP must think we are DIY guys who have just started to fix engines on the side. I can see that over 125 years of experience by those who are trying to answer the OP’s post is not going to change his mind, IT’s BRIGGS FAULT. Bert, IL, Star and myself are just trying to point out that in our experience we have all seen engines with rods and cranks exactly like this and in nearly every case the cause was overheating, probably caused by lack of lubricant. You may not like our posts because they don’t support your ideas, but trying to belittle us isn’t going to work here. We help members solve their problems based on our past experiences and YES everyone of us has made mistakes, but for all of us to come to the same conclusion, from the same information give, would probably be a first on this forum. As IL posted earlier, in posted #12, get all your information together and present it to Briggs. If they say we are wrong I’ll be the first one to apologize to you and I’m guessing so will some of the others.

I wasn't going to pile on but....... looking at the pics from the colors of the crank it got very hot. When the rod cap is loose it gets hammered. No hammering marks in the pics but wiping and transfer evident from overheating present. I have opened many engines with perfect bores but with rods seized on canks from lack of oil.

I am also an independent repair shop and believe you me no lover of B & S or the engines they make.
In my post I did mention a likely scenario , there are others.
I have been playing with engines since I was 12 and playing with motorcycles in particular for 55 years.
This includes things like cast in place babbits so I seen a bottom end or twenty thousand .
There are a lot of other tell tales as mentioned a loose journal does not normally pick up alloy if there is the slightest drop of oil in the cases
And in particular pick up so uniformally.
A no oil bottom end can bind and break a rod before the plug has had time to colour and well before the piston has expanded enough to sieze in the bore .
When I rebuild engines, the rings go in bone dry, in fact I use brake cleaner as the lube to get them into the bore so it evaporates before the first stroke.
The piston rings need more oil to make a proper seal than the bore does to lube with
Add to that when the engines are made, the rods are done up as they are fitted , not finger tight then tensioned as one would do in a repair shop.
The bolt is put in the tool then the tool fits it and tensions it in one operation
So if it was loose from day one it would have to be a deliberate act of sabortarge

Hammermechanicman said:

I wasn't going to pile on but....... looking at the pics from the colors of the crank it got very hot. When the rod cap is loose it gets hammered. No hammering marks in the pics but wiping and transfer evident from overheating present. I have opened many engines with perfect bores but with rods seized on canks from lack of oil.

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Discolored crank was one of the first things that got my attention.
That thing would have knocked for some time before it made the rod look that way. Lack of oil...... JMO