What is a spun bearing? Can you drive on a spun bearing? You can have a spun rod bearing or a spun crank bearing and when they fail, it sometimes destroys the engine like in our Lemons BMW. In this video I show you how to diagnose a spun bearing and possible causes. We disassembled the entire engine, every single nut and bolt, so you guys can see what causes an engine to throw a connecting rod and fail.
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Hey guys chris fix here and today, i'm going to show you what caused our lemons, bmw engine to catastrophically fail at our very first endurance race. So at this point of the race i just finished my first few laps and we switched drivers. So now it's aaron's turn on the track. Aaron was doing amazing.

He moved up nine positions in just seven laps, but at the end of the half mile straight after braking hard from 100 miles an hour into a tight turn, the engine let loose and sent rod number two to the moon. We actually got some footage from another team and you can see right at the end of the street. There was a huge cloud of smoke and that's where our engine blew up. So aaron ended up pulling off the track because the engine was running rough and there was no oil pressure and we got the car towed back to our pit.

Well, that's not good any idea what happened! I have no clue. After doing a little bit of diagnosing, it was pretty clear. The engine was toast. That is a rod.

Well, it was. It was at some point, so we ended up finding another engine at a local junkyard and we tried swapping engines at the race, pull all the way out. Pull it out, don't drop down. That's about all.

We have yeah, that's fine. We got our old engine out and we saw the extent of the damage which was pretty bad with multiple holes in the block. Unfortunately, there wasn't enough time to get the junkyard engine into the car, so we pushed our race car back into the trailer and that's the last that you heard of this car now back home, teammate pierce asked if he could take the lead and put the junkyard Engine back into the car, so he and his dad took on the project and had a lot of fun with it. First pierce disassembled the entire junkyard motor and just left the head on.

He then installed the very important aftermarket chain tensioner on the oil pump. These oil pumps are known to fail and this fixes it so he marked where he had to drill. Then he drilled two holes in the block and then threaded the new tensioner into the block and with a sigh of relief that new tensioner fit perfect pierce. Also wire tied the oil pump nut because they're known to back off at high rpm, and then he took apart the vanos, which is bmw's, variable valve timing, and then he rebuilt it and then he replaced all the seals on both the engine and the differential.

That way, our bmw will be the only bmw on the track, possibly in the world that doesn't leak, fluids and finally, pierce went on a cleaning spree and cleaned everything he could and with a clean engine. It's a lot easier to work on. Also, you could easily identify leaks and problems that you might have so with the engine all put together fresh seals, all cleaned up, looking amazing, he got it back in the car added some oil and the swap was complete all right. So pierce did an awesome job.

Freshening up this 140 000 mile x3 engine and getting it installed and we are ready to race. It is good to go. Let's start her up, so she starts up on the first: try, nice and quick. She idles nice and smooth, and she drives great.
So we are ready to race. Now we did learn a bunch from our first endurance race and the first thing we learned is: we need seat time in this car before our next endurance race. Everybody needs to go and do a bunch of laps. We need to practice getting in and out.

We need to practice fueling up, we need to practice taking the turns just get a good feel for this car and be on it. That way. We know the engine is going to last and that way, if anything fails, it'll fail before the race, not during the race. We also learned that this car is way too quiet with the stock exhaust, so listen to this, so that sounds really good and how we did this was we got stainless steel, full length, headers and you're, probably like chris, but there's a 500 budget.

Well, guess what these cost a hundred dollars! I found them on ebay, full-length, stainless steel, headers they're, actually really nice and they fit really well. They fit so well that i have an extra pair here because my buddy bought them for his car and he's gon na put on his bmw. So we have headers, we have the rest of the stock exhaust and then, if you remember, we cut off the muffler at the racetrack which not only saved us 20 30 pounds, but it also makes this car sound awesome. So we're staying under budget we're getting the loudness that we need.

So we could hear what rpm we're at we're. Getting a little bit performance gain it'll help the engine run better. We don't have these big hot heavy cats right next to the engine and overall it's perfect. It's exactly what we needed for this car now real quick.

I want to show you the huge difference between the stock exhaust manifolds and our aftermarket headers, and you can see it already, so the exhaust gases are flowing out of the head into this manifold. Look at how thin this manifold is look at that. That is tiny and it pinches down, and then it turns 90 degrees here and then it turns 90 degrees here into a restrictive cat, and then you have all these bends going out is just not good. Now compare that to our header.

This is all mandrel bent, tubing, nice and smooth equal length, all the way down to our collector, and that is just going to be so much better compared to this, and we don't have a cat since we're on the track. We don't need to run one which is great now, since this is a straight six. We have two of these exhaust manifolds and look how thin this is again crazy, restrictive, 90 degree turn into a restrictive cat. Compare that mandrel bent equal length tubing.

Our headers are going to make a huge difference here and not only will there be a difference in airflow, but wait. These weigh 30 pounds. These weigh eight pounds, that's a huge difference. Every little bit counts on this race car and the second thing we learned with endurance racing.
You always want to have a backup engine. Just in case. I don't plan on this going, but if it does, our team now knows how to swap out an engine in this car very quickly. So a backup engine is a great idea and have a friend down in florida, jamie with elite motorworks.

Who knows how to make these engines super reliable, so he's gon na go and freshen up an engine for us, so we could have it as a backup check it out thanks chris guys, my name is jamie. I'm the owner of elite motorworks when it comes to endurance, racing reliability is absolutely a must. Last year chris and his team had an engine failure and they needed another engine, but they didn't have one so they're out of the race. They don't want that to happen again.

So chris has asked me to build him, the most reliable backup, bmw engine ever so i'm taking a bmw m54. I'm tearing it all the way down to the block, i'm rebuilding the engine to make it more reliable than new, and i'm doing it by using upgraded components. Now we're not adding horsepower. What we're doing is we're really just making it the most reliable engine ever so.

Don't worry chris, i got you now if you guys want to see our backup engine get completely rebuilt. Jamie is filming the entire process for you guys from tearing it down to the machine shop to building it back up. He knows the ins and outs of these m54 engines. He will show you what commonly goes wrong and how to correct it.

I'll leave a link to that video in the description it's up now. It's a great video jamie's, a great mechanic, really nice guy and i think you're gon na like it. So we have our junkyard engine installed, ready to go for the race. We have a backup engine being built right now, which will be ready by the race.

But what the heck happened to our engine, that was in the car when we got it. This is the engine we took to the race, and this is the engine that didn't make it home. But what caused the problem and our race team is really methodical. We like to know exactly why something fails so that we could correct it, so we tore apart this engine, completely every nut and bolt every bearing every piston.

Everything is taken apart, so we could analyze it and see what went wrong. So, let's start right here with what failed cylinder number two you can see the rod and piston are destroyed, so this is what it should look like and that's what all the other rods and pistons look like they're all completely fine, and this is what cylinder number Two looks like it's completely mangled and we think right here at this interface, where the bearing cap and the rod meet. We think that's the main point of failure. That's what all started it! So what caused this? Well, the first thing you would think of for this engine is the oil pump.

We lost oil pressure. This is a very common problem on this engine, so it's very common on these m54 engines for this to fail right here. This sprocket there's a nut on here. Usually we're actually using the nut in the new engine, it's wire tied and all that.
But this nut because of resonance because of vibration at high rpms backs off. And then this sprocket comes off and then now you lose all oil pressure, because the chain can't drive the shaft which drives this pump. Now, in our case, that did not happen. Here's the bad motor on race day, and we were convinced this blew up because the oil pump nut came off but as you can see the nuts still on there and it was actually on there tight.

So our oil pump was completely fine. It worked and we did not have an oil pressure. Light come on until after the engine threw a rod, so it wasn't. The famous oil pump failure that caused this entire failure.

The next logical thing we could think of was driver. Error aaron was at the end of that straight high rpm. He had to downshift multiple times and slow the car down, so he could have money shifted by accident, meaning he could have overread the engine by shifting incorrectly. But luckily we were datalogging the engine, speed and coolant temperature.

So right here you could see the engine rpm when aaron was driving and for this engine redline is 6500 rpms and you can see the engine never revved past, that rpm, so aaron definitely didn't over rev. The engine and just so you have an idea right here at the 16 30 mark, that's where the engine blew up now, looking at the coolant temperature, you can see the coolant temperature when i ran the car and that's the green line, and you can see the Coolant temperature when aaron ran the car and that's the blue line, and you can see aaron pushed the car a lot harder. He has a lot more experience, driving bmws, so he's able to push that car now right at this mark is where the engine blew up and just to give you an idea. This is an all-aluminum engine, so our coolant temperatures should be within the zone of this green area even a little bit above.

That is fine, especially on the track now, where you don't want to be. Is this red area now that you know that you can see where the engine blew up and then it actually got a little bit cooler, because that was at the end of the straight. So the engine had time it was still running it had time to cool down and then a half a mile later he drove off the track and shut it off now. The reason why the temperature spiked after he shut it off is because the coolant is no longer flowing, so all that friction, all that heat that was created from this broken engine is just heat soaking and has nowhere to go.

So that's why it spiked to over 245 degrees fahrenheit. So having access to this data was amazing. We know we didn't overheat the engine. We know we didn't money shift the engine we didn't over.

Rev it and aaron actually did a great job at driving. It is very consistent way more consistent than me. He is a great driver, so it wasn't human error that caused this failure and if it wasn't human error, then what caused it well after analysis of this entire engine, we've come to the conclusion that the engine spun a rod bearing in cylinder number two. It's very easy to tell this was a spun bearing, but real quick.
Let me show you what a spun bearing is so these are a set of rod, bearings and you can see that they are worn down to the copper. Normally, you would see a silver color kind of like this bearing, but even this is worn down all these came from that bad engine, so it's gon na have wear marks on it, but without that wear mark in the middle you could see the kind of gray Color that gray color should be consistent across this whole bearing surface and it's not because it's worn down that is called a babbitt layer. That is a mixture of metals that is a very low friction surface and underneath that is a copper layer which is good at taking compression from the engine and then behind. That is the steel backing of the bearing.

So if you could see copper or you could see score marks like this - you know your bearing is toast and all these are toast, but that doesn't change how a bearing works so how a set of rod bearings works is typically, these will clamp in so it'll Clamp into the cap and clamp into the rod, these are just so loose because they're worn out but pretend these snap in place and they sit on the rod like that. So with the bearings snapped into the rod, they are one with the rod. Now the rod will clamp down onto the crankshaft like that, and then you would just tighten these bolts down to connect the rod to the crankshaft. Now these bearings will never touch the rod journal surface.

This surface right here will never be touched by these bearings. There will always be a thin film of oil on here. You can see that right there, that is an oil gallery, that's a hole in the crankshaft that provides oil pressure that puts oil around this. So with an engine that's running perfect, these will never touch that journal.

There's always oil in between and that's very important. So basically, the rod bearings are always connected to the rod and they ride on a thin oil film around the rod journal of the crankshaft. Now, if you lose oil pressure or if your bearings are worn out just from bad maintenance - and these bearings touch this surface here, they will grab onto this surface and once these grab onto the crankshaft surface, they're, just spinning and they're, going to spin inside of the Rod and the rod does not have any lubrication, so this spins really fast, 6 500 rpms fast over and over and over, and this will heat it up because of all that friction, and that is how the rod bearings fail. So that's literally what a spun, bearing is it's a bearing that grabs onto the crankshaft surface, because there's no oil, film anymore and it literally spins inside of this over and over and over until it just catastrophically, fails and that's why, when you have a spun bearing The bearing is toast - and this becomes black - so not only can you see the black heat mark on the crankshaft, but you could also see it on the rod itself.
So take a look at this again. This is all discolored because of how hot it got. It's black in there you can see that kind of rainbow dark effect that you get when you have really hot metal. You see that rainbow effect there.

You know when you heat metal up a lot, it kind of turns a rainbow color, because it's overheated well, that's exactly what happens here and not only does it change the color of the metal, but it changes the strength. There's a lot of force going on. As this engine is running and all of a sudden, this overheats now these little rod bolts, they start fatiguing, they might break off and then this separates and then now you have your rod banging around inside the engine and that's what actually blew through our engine block. That's what created the hole, so this was banging around in here until it bursted through and destroyed that block, and then this piston head is what hit the valves.

You could actually see the exhaust valves and the intake valves this actually bent the exhaust valves. You can see the exhaust valves are completely bent open. It should look like that, but those are stuck open and that's because our piston hit those exhaust valves and that caused our piston to crack. So now you know how to diagnose if your engine has a spun bearing, and you also know what a spun bearing actually is, but what causes it so almost every cause of a spun bearing is related to an oil issue.

First, you could have dirty oil, because your air filter or oil filter isn't doing its job properly, since there's only a thin layer of oil on here. If it has dirt in it, the dirt could increase the friction enough to spin the bearing especially at high rpms. Next, you could have oil contaminated with fuel, coolant or water. Again, there's only a thin layer of oil on here.

So if there's water or fuel in this oil, it could thin it out and that won't provide enough protection and the bearing will make contact with that crankshaft journal and that could cause the bearing to spin next, your oil could be broken down. Oil that hasn't been changed often enough, could be broken down and the viscosity or the thickness of the oil isn't enough to provide the protection needed to lubricate the bearing so the bearing could make contact with the crank journal and the bearing could spin. Next. You could have too much oil if your engine is filled up with too much oil.

The rods can actually splash the oil, creating bubbles and those bubbles in the thin film of oil won't protect the bearing and the bearing, could contact the crankshaft journal and then the bearing could spin. Next is the opposite problem. You could have oil, starvation or not enough. Oil pressure, if the car is taking sharp corners like on the race track, the oil could slosh to one side of the oil pan, causing the oil pickup to suck up air instead of oil, and in that case the engine will be starved of oil.
You'll have zero oil pressure or if the bearings are just worn out from the car not being taken care of with regular oil changes, or maybe it's just a really high mileage engine. You could have low oil pressure, which could cause the bearings to make contact with the crankshaft journal and spin. So how do we know what caused a spun bearing for our engine? Well, luckily, we have an oil sample. You guys remember.

We took an oil sample at the track as we were, removing the blown-up engine and here are the results. So you can pause the video and read the whole thing, but i highlighted the important parts there were high levels of iron, copper, lead and tin, which indicates that there's bearing wear since that's what bearings are made of. Also, there is no fuel or water or coolant in the oil, and the viscosity was exactly what it should be 5w40. Finally, there were low insolubles, which indicates that the air and oil filters were working, so there was no dirt in the oil and real quick.

If you want to look at the actual numbers, you can see how high the iron copper led in tin numbers are compared to the averages, and these averages are at 6 000 miles of oil use and we only ran the engine for about 40 miles. But we ran it pretty hard on the track, so we definitely did have significant bearing wear and at the bottom you could see that we didn't have any fuel antifreeze or water in the oil and the insolubles, also known as the dirt in the oil were low. So our oil sample analysis showed us that our engine oil was perfectly fine, no contamination, it wasn't the issue. So then we started thinking.

Maybe oil, starvation or low oil pressure because of taking hard turns was the cause. So this is our oil pan. Here's the pickup tube - and this is about where it sits in our oil pan. Now in e46s, you run about an extra quart of oil which prevents starvation, but this is an all-wheel drive version, so we have something even better.

We have a built-in baffle. This is a baffle here because our axle actually goes through this to the differential which would be over here and since we have a differential over here. This squeezes the oil pan shut. So we don't have much room for the oil to slosh around when we're taking sharp turns.

So this oil pan is actually designed very well to prevent oil starvation. So that wasn't the issue. What we think happened is we had low oil pressure and the reason we had low oil pressure is because we had a worn old, 240 000 mile engine that wasn't taken care of. Obviously, the previous owners did not take care of this car, which is how we got it so cheap.
And if you look at the gauge cluster in the car, we don't have an oil pressure gauge. All we have is this idiot light that will turn red when oil pressure is below 7 psi. So we had no clue what the oil pressure was just that it wasn't very, very low so with an engine that isn't worn out and is in good condition. The oil pump at higher rpms we'll be pushing 40 to 60 psi of oil, and that is enough to protect these journals, to make sure that there's oil on here and the bearings do not touch them now.

In our case, we obviously had a worn engine, so we're thinking. Maybe we had 15 to 20 psi coming down that straight at 6, 500 rpms and it just wasn't enough. It wasn't enough oil pressure. It wasn't enough oil film on here to protect the bearing from hitting this journal and eventually it hit it hit it enough heated up enough and it spun and that's exactly what killed our engine so a spun.

Bearing is what caused our engine to catastrophically fail, and i think that gives you guys a good idea of what happened at our very first lemons race. Now, what's next for our lemons, bmw, we're good to race with our engine, our engines in there, and we are good to go, but before the next race we definitely need to get a new livery on this car. You guys sent me a bunch of awesome liveries, but none of them made me fall in love. My favorite one is probably this one right here, but i feel like the body kit and wing also make this look cooler.

But again, i feel like there's aspects on all these different ones that you guys sent in which i like we don't want it to be too busy. But at the same time we don't want to look boring and i want everyone to instantly recognize this car. Among the millions of bmws out there, the lemons race is supposed to be a junk car. So i like that rat rod, look like this or like this, so i think we should try to incorporate that into the car somehow, but so far nothing has stood out enough for me to make me say: hey we need to make sure our car looks like That so, if you want to screenshot this video and email me, one of your livery ideas feel free to do that, because we're definitely going to have a livery on this car before the next race.

Now one last thing i want to show you guys, i don't think you noticed, but i actually removed the fire suppression system. I removed the battery cut off and i put the old steering wheel back in because i learned a ton from this race and i want to show you guys how to properly install all three of those things and we're actually adding some additional safety factors to it. Things i learned from the race and i think you're gon na love it so we're gon na do a video on how to properly install a quick release, steering wheel and we're gon na keep the horn function. So i'm gon na show you how to wire.
In a horn and we're also gon na move our radio communication button to our steering wheel. So this is the mount right here. It'll mount right behind our steering wheel like that, and the button goes right there. So we don't have to take our hands off the steering wheel in order to press the button to communicate with our team, then i'm going to show you how to install a fire suppression system as well as do a test fire.

Okay, we got a fire in our car man that is hot, quick and we're actually gon na install two systems, a manual system that you pull yourself and an automatic system. So if the driver is unconscious, it could still put out the fire. And finally, i'm going to show you how to install a battery cut off properly, so it kills the engine and cuts the power from the alternator and battery. That way, if you wreck, you won't have electricity that could spark and start a fire.

It's also a good theft deterrent device which makes it more difficult to steal your car. So there you go. I hope you guys are enjoying this series and i hope you enjoyed this video, our very first endurance race. It didn't go the way we wanted to, but we learned a ton and we're going to come back stronger than ever.

If you enjoyed the video remember to give it a thumbs up, if you're not a subscriber, consider hitting that subscribe button, we have a lot of really cool and helpful videos on this car coming up and as always, all the tools and products i used in this Video are linked in the description, so you can easily find them.

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