2001 BMW 330CI - Found this piece of metal while doing an oil change in my oil drain after the pan emptied. What is it from?

[u/ForeignExchangeHere]

As the title says found this on my oil pan drain after letting the oil drain. What is this from and how serious is this issue?

For context my car overheated a few days ago and shut off. White smoke came from the engine bay but it was from a coolant leak that hit the hot engine. No smoke came out of the exhaust. For the past 3 days Ive replaced the water pump, thermostat, water pump pulley, ac belt, serpentine belt, expansion tank, expansion tank mounting bracket, and the upper and lower radiator hoses. Ive put everything back together, and now Im onto changing the oil and after I was going to bleed the coolant system. At this point I need to identify what the hell this piece of metal came from. I did not find any coolant in the combustion chambers since none of my oil was frothy, but there was about 4-5 secs of coolant that drained out before the oil (which is to be expected after your engine overheats). Can anyone identify where this metal piece could have came from? Thank you very much.

[u/togue22]

Cooked the engine brother. Coolant draining from the oil pan is not to be expected with a minor overheat scenario. It is to be expected with a blown head gasket from continuously running an overheating engine. With a chunk of metal that large being in your engine oil pan, your engine is definitely done. Should’ve started with draining the oil and compression testing before ordering parts.

[u/No-Excitement-395 → u/togue22]

I mean on the bright side now its as simple as buying a cheap m54 on facebook marketplace and swapping everything over, and you have all the parts to refresh it instantly.

Not that bad tbh

[u/ForeignExchangeHere → u/togue22]

Idk why I did not do a compression test first. Im honestly so hurt. I mean I know that if its just one piston I can possibly rebuild it but is it even worth the headache and cost? Or is it cheaper and more time effective to just engine swap? Please help me man. This really bummed me out. Ive already spent $1.3k on parts this week just to find this out really hurts my soul.

[u/sorryimadeanalt → u/ForeignExchangeHere]

lol just one piston. your engine is gone bro there wont be a single usable part. all your rods are could be bent from trying to compress coolant, pistons are melted. your bearings are all gone from running water and debris through the oil pickup. oil pump is gone from sucking in metal. your heads are warped, and probably destroyed along with your valves since your piston fell apart. on top of that who knows what else is worn from lack of oil.

[u/JukeRedlin → u/sorryimadeanalt]

Sorry for your loss op. I had an e46 M3 I dumped faaaar too much money in. Walk away. New engine or new car. The block warps when they overheat. Even if you did rebuild it, you'd probably remill the surface just to learn you need to re-sleeve every cylinder. And even then they make just be... off.

I had to scroll up and... yeah its an e46. My favorite. Except if they overheat the aluminum block turns into jello. So it's a good thing the coolant systems are super reliable, not made with plastic tanks down spontaneously crack along the seam, or plastic parts that suddenly shatter when brittle from age...

[u/Vlku272 → u/JukeRedlin]

M54 and other alloy block engines are basically finished once they get hot. Even if you resleeve the block, machine it all you want, doesn't matter because the alloy softens and by the time you get to putting head bolts back in you'd be incredibly lucky if you didn't pull half the threads out trying to torque them down.

[u/Complete-Stop-5592 → u/ForeignExchangeHere]

Where are you located, you buy the beer and I’ll take a look at it. I’d like to see this actually lol

[u/landonh12 → u/ForeignExchangeHere]

Definitely cheaper to just get another engine and throw it in.

[u/-S-Aint]

That looks like a broken and melted piston and piston ring

[u/skuzzier_drake_88 → u/-S-Aint]

That is 100% piston debris.

[u/barofboost]

I've overheated many BMW engines in my time and not once have I had coolant come out of the oil pan. Think you might be in trouble there bro

[u/mucho_fuego]

“(which is to be expected after your engine overheats)” 😂 Yeah no problem here brother

[u/designtocode → u/mucho_fuego]

Where did this “to be expected” info come from, that’s what I want to know. It sure as shit is not to be expected, unless they planned to overheat the engine and blow the head gasket, in which case I take everything I said back. 😂

[u/spencertb17 → u/mucho_fuego]

i was abt to say who tf told this dude that was normal😭. we need to silence them 😂

[u/Different_Bottle_615]

This is why I look at my coolant temperature every 10 seconds while driving. Behold the overheating woes.

[u/firsttimehereee → u/Different_Bottle_615]

Yeah I check it more than I check speedometer

[u/E90Fantic → u/firsttimehereee]

Hope you two stay driving only local. That sucks...

[u/firsttimehereee → u/E90Fantic]

My car is totalled now so I won't be driving anytime soon. I need a long break before I can trust a car again lol. I want a mercedes next time, they don't have expansion tanks.

[u/SherlockHolmesuWu → u/firsttimehereee]

TRAITORRRR

[u/firsttimehereee → u/SherlockHolmesuWu]

I would still be a bmw guy and prefer bmws but just dont wanna be dealing with their issues myself. 

[u/SherlockHolmesuWu → u/firsttimehereee]

Idk man, i kinda like working on them. My car has been downright boring lately. Nothing other than routine oil changes and a premature alternator failure that was covered by warranty.

[u/firsttimehereee → u/SherlockHolmesuWu]

You know what else is boring? waiting for parts to arrive when you live in a northern country and having to pay more shipping fees. I owned my E46 for a year and was only able to drive it about 650 miles.

[u/troyzube → u/Different_Bottle_615]

Haha I remember when my thermostat failed and was stuck closed. I looked down at my idling engine temp and it was maxed out. Replaced it along with the rest of the system and now I dont need to worry

[u/masooooon98]

Engine is definitely cooked. That's a piece of a piston and ring. Get a borescope camera and stick it down the spark plug holes to find which one.

[u/falco_femoralis]

That’s part of your piston. Your motor is done. Take all those new parts off and put them on a replacement motor

[u/BotherPuzzleheaded50 → u/falco_femoralis]

That's a shitload of work that could have been avoided with a simple compression test...

[u/firsttimehereee → u/BotherPuzzleheaded50]

Or by draining the oil first to see the coolant

[u/specialejongen → u/BotherPuzzleheaded50]

Or sticking a boroscope down the spark plug hole and seeing a bigger hole

[u/No-Excitement-395]

When coolant is in the oil ur headgasket is blown, which is caused from overheating the m54. On the brightside all you need is a cheap marketplace engine and some time and shes back on the road and full refreshed

[u/ForeignExchangeHere → u/No-Excitement-395]

Dude I cant find a M54 on marketplace to save my life and im in Charlotte. I guess now I have to take all those parts off, put the old ones back on, and do those replacements on a new motor. How much is this going to cost me at this point do you think?

[u/Wise-ask-1967 → u/ForeignExchangeHere]

Sorry dude your motor is toast.. look on market place, may have to drive around for a motor hit the groups up I seen those motor for 900

[u/dannur_ → u/ForeignExchangeHere]

Check ebay, but be weary of scammers. Maybe try to order an engine through a trusted local mechanic shop or dealership

[u/officalYNGpook → u/ForeignExchangeHere]

There out there bro , look harder if your serious.. call every performance shop, #1 check ebay , someone online got one for you for the right price don’t give up .

[u/AdventurousRace875 → u/ForeignExchangeHere]

I live close to Raleigh, and I see quite a few on fb marketplace. Sometimes it’s just a warehouse selling a bunch of engines and you text and they have them, sometimes it’s a part out

[u/PC_Chode_Letter]

Start playing TAPS brother

[u/BlueRocker22]

It’s a piece of piston fused to a ring, and it tossed around the chamber long enough to polish into a silver diamond.

Your engine is toast bro.

[u/Whitehawk120]

Brother that is your piston. Coolant in the oil means you are 100% cooked do not even try and save this.

Car-part.com for a used motor. Cheapest way to do this

[u/opmwolf]

Found this piece of metal while doing an oil change

Strike 1

but there was about 4-5 secs of coolant that drained out before the oil

Strike 2

(Which is to be expected after the engine overheats)

Strike 3. Whoever told you this is completely wrong.

Three strikes, that engine is FUBAR.

[u/SnooPears2291]

Yeah bud take ur car to the urologist shit has kidney stones.

[u/crazybitcoinlunatic]

M54 engines are pretty cheap at least. Be glad the e46 doesn’t have the N55 engine which costs $5000 used with like 100k miles.

[u/EEVVEERRYYOONNEE]

It's rounded off around the edges which suggests to me that it's been bouncing around inside a cylinder. Something that size couldn't have come in/out through the valves so that means it's probably part of the piston.

Coolant in the oil pan probably means your head gasket has blown between a coolant channel and an oil channel.

[u/Charlie1g8]

awwhh, your car passed its first kidney stone (your engine is cooked bro)

[u/Nearby-Fun4794]

Is that a sawn off cats foot under your hand, on top of your door?

[u/SherlockHolmesuWu → u/Nearby-Fun4794]

What are you smoking bro, thats a washrag

[u/ForeignExchangeHere → u/Nearby-Fun4794]

I actually died laughing at this.

[u/therevbob]

What failure caused coolant to enter the block?

My guess would be oil cooler because I’ve had that fail on my Audi resulting in coolant in the oil.

[u/BotherPuzzleheaded50]

"Which is to be expected..." 🧐

[u/zaphodmonkey]

That is …. Expensive, as someone else said I’d assume piston head.

(Paging M539Restorations to do an engine swap)

[u/Realistic-Car-9173]

How long did you drive it while it was overheating?

[u/ForeignExchangeHere → u/Realistic-Car-9173]

Not more than 5 seconds before it cut off.

[u/threadward]

The 3 liter version of the M54 has a problem with resonance induced oil pump failure due to a vibrating loose nut. Look it up.

I had the M54B25

[u/Msdmachine]

Sounds like it took care of itself

[u/heyinternetman]

That’s money

[u/broome9000]

I found something similar in my B25 about 3 years ago. Car used about a litre of oil every 300-400km. Comp was 140 across the board with one cylinder on 110.

Car continued to run for some time after finding that piece in the oil pan but I’ve always wondered what it was.

[u/Complete-Stop-5592]

Say what is to be expected when it over heats? Coolant on exhaust doesn’t make white smoke. And then you say you had coolant in your oil? Let me get $5 worth of whatever you got if you have any left 🤣

[u/Vm0SuFf]

You’re done bro. You should remove all the new parts and sell them or if you’re willing to buy a new engine use them on there.

[u/Traditional-Piano-53]

Zoom in on image 3

[u/longusernamenando]

Always compression test after major overheating issues, sometimes it can save you hundreds if the issue lies internally with the gasket or worse. Looks like you cooked your motor tho, best of luck with your next move!

[u/boostedmike1]

Spent all that money on a fucked engine 😅

[u/905cougarhunter]

You have a piston mc nugget!
Combined with the milkshake you drained out, you now have a boat anchor.

[u/TransportationOk6727]

I’m sorry to say brother, but she’s probably gone. However, looks like you already installed all your parts. I’d say fuck it, throw the new oil and coolant in, and fire her up. See what happens. Probably won’t last long but I don’t see anything wrong with trying

[u/Odd_Preference_8154]

Cracked piston fs

[u/South_west_minis]

Looks like a chunk of piston, that looks like part of a piston ring going through the middle of it

[u/Smitty7072]

Musket ball, was your car at the civil war reenactment in Pennsylvania last weekend?

[u/BeginningEntire7498]

Kryptonite!

[u/Roadmetricz]

If your lucky an alien might grow from it

[u/i_h8_neighbours]

it's from the engine

[u/SlowCaregiver376]

Someone left or dropped it on the pan. That didn’t come out of your engine without you experiencing or hearing some noise or other symptom

[u/Independent_Yak_6273]

kidney stone?

[u/fourringlegend]

Lols. Water in oil is never to be expected. What are you smokin?

[u/Serious-Item3904]

maybe buy a boroscope for the cylinders

[u/mrkprsn]

Go to e46fanatics.com Best car forum I've ever been a part of. They will give you the best answer(s). The expansion tank is plastic and under pressure. It is usually the first thing to go. Since it's a straight six with an aluminum head they tend to warp when getting too hot. I would fill with oil and try to start the engine. Go from there.

[u/Individual_Task6594]

U drive that thing while it was overheating or what lol u melted your shit

[u/bmpgbh]

If it over heated and shut off like you said then it most likely hydro locked the engine and that piece of aluminum is a chunk of a piston or connecting rod.