Another DEAD BMW N55? Complete Engine Teardown. Neglect OR Bad Design? 

The worst tear down I ever saw in my life!!! Find another job, dude!

Coking is what I see with this engine, usually from petrol based, conventional oil. The fact that # 6 rod bearing seized to the crank, indicates it had no lubricant making its way to that bearing. I would call the piston skirt wear advanced, not minor and not normal. This engine definitely had piston slap at cold startup. I also observed scoring on the cam lobes, journals. So what is the conclusion? Seized bearings in the low end are usually the result of rapid acceleration without adequate lubrication. Petrol based oil is what I determine from the coking seen throughout the engine. Coking is usually caused from oil burning, associated with oil that has not been properly maintained, or a vehicle that never reaches operating temp (driven short trips only) In this case I am going to go with not properly maintained. So why did the bearing seize? The crank bearings look acceptable The other rod bearings were not showing wear into the base copper. So why only the # 6 rod bearing? It’s lubed from the crank just like all the other rod bearings. …. Think about what occurs when the explosion of spark igniting a compressed gas air mix, occurs inside a cylinder, which in turn forces the piston rod against the crankshaft, to turn it. Oil must be able to maintain a film barrier, capable of handling the force exerted against the crank, by the rod bearing. In this case there was not sufficient lubricant to withstand that force, allowing the rod bearing to physically contact the crankshaft. Turbo boosted engines exacerbate this issue. The fact that it happened to the #6 cylinder is the hint, as it’s the last rod bearing to receive lubricant in an inline 6 cyl. Piston scoring is a hint. Heavy oil deposits on the valves are a hint, and finally Coking is a hint. This engine was low on oil, most likely cheep petrol based oil that had a poor centistoke value at operating temp. Oil that evaporated at low temperatures leaving deposits (coking), oil that was additionally low because it was being fed into the valve train, hence the deposits on the valves. When that turbo charged mixture exploded in the #6 cylinder, the rod bearing impacted directly into the crankshaft, because there simply was not ample lubricant to withstand the force of the impact.

165k on my N55 CHANGE YOUR OIL OFTEN!

Almost a million miles driving BMWs... I can't remember the number of times I've pulled the valve cover to replace the gasket!! 🤣

It's owner neglect, more often, that leads an engine to be on the channel, it seems. Nobody changed the oil, obviously. Simple maintenance can't be overstated. Nice video

I lived in Germany for several years, and the joke about BMWs even among the Germans was that when you drive up to the shop to have them repaired, the shop owner would immediately call home to tell his wife to book another vacation to the Med, because the cash was soon to be available to go on it!

Loved the water pump toss at the end. "I hope it went in." Pure gold.

Oil filter crushed like that is from poor flow created by immense suction from clogging. Usually dead give away to poor oil change intervals.

151k on my 2011 335i with N55 engine and going strong, I use LM engine flush every 3 oil changes, change oil every 5k miles and it works like a charm, only thing I've had to replace were spark plugs and ignition coils and valve gaskets after walnut blasting the valves, not even rough idle issues so far.

10 years ago my son was looking for a used SUV. He was looking at small Hondas, but he also like the acura version (@10 yrs. used). Vehicle for vehicle the Hondas were much better maintained, whereas the Acuras were mostly on the verge of neglect. It perplexes me that people will buy an expensive vehicle, and then treat it like trash.

Favorite part of my Saturday evening is a good tear down

I have was a mechanic for 40 yrs in motor and worked till became too poorly to carry on , I rebuilt a Aston DB8 and worked for jag in my early years and watching this , was amazing thank you, sat at home in the warmth, I will watch and subscribe ❤️

Thank you Eric, for all the videos, and thank you Mike, for all the work editing!!

If you ever think your job is meaningless, remember this. There's a guy working a BMW assembly line that installs the blinker.

Thanks for being so punctual Eric! This is one of the things I look forward to after a long week at work. Keep it up man!

It's unbelievable these owners of such expensive cars can't have basic maintenance done! Great channel Eric!

I love videos like this. I could watch buildup or tear down videos anytime. I also like to know how things work. How something can be made better. Learning from mistakes you could say. I also agree with his statement; any brand can and has made some good engines and some have made bad ones as well. I like BMW's and Audi's as well but i think they over complicate things when it comes to some of their engine designs. I think sticking to simple naturally aspirated engines are the best bet.

It’s that time again! Thanks for all the content you put out weekly. Sit back with my phone and some smoke to finish off this rainy wet Saturday.

Smashing the timing chain guide was hilarious. Me and my 13 year old son watched that part several times.

"The crank is the highest value item" It was at this moment that I knew the crank would be fried...

Thanks Eric. Its amazing how many important pieces on these motors are made of plastic (water pump, oil pick up etc).

Your style with the injector puller seems very well practiced

Awesome video Eric. Thanks for my Saturday night entertainment. I thought you were going to need a jackhammer to get that bearing off the crank. :)

Great video! and to Lunchboxsteve's note, the pace of the teardowns are great! Just spent all week pulling one of broke injectors and this was helpful to see the overall design elements.

Been watching you since you started these tear downs. Great stuff.

Aluminium bolts? Neat! Next step should be plastic ones, they won't rust and are even lighter!

Hi Eric due to the time difference here in the UK watching your show is part of my Sunday morning ritual as my wife calls it. Keep the vids coming mate!😀

I too enjoy watching you tear down engines. I find it relaxing and informative. I almost said...what?..No water pump toss?? then you came through at the end....thanks.

Love it!!!! Nice I am glad you got another N55!!! Love your teardowns especially now that I own a N55! You make me laugh and think at the same time with your attitude and perspective! You are showing me a perfect example of how to take care of the Motor and what never to neglect even at it's most simple (Oil Changes on the regular) Very informative as always!

This channel has matured into complete anarchy!! Eric - you kick ass and may one million subs come your way!

I did full synthetic oil changes on my N55 every 5-6k miles. Spun rod bearings at 79k, the good indie shop I use wanted five figures to swap the engine in a ten year old vehicle. Taking a break from this brand for now.

ive had my 2011 n55 tuned since 70,000 miles, pushing roughly 15lb boost on a pull, 18, on a colder day. current;y around 150,000 miles and still running strong. oil changes roughly 7-8000 miles after blackstone labs oil testing and recommendations. had rod bearings done when I replaced the oil pan gasket leak. figured since they were there, do the bearings. bearings had very little wear. havent had issues with this except one day the eccentric shaft went out around 125,000 miles. theyre not all bad.

A very useful tear down of a modern basic engine, we can all learn the importance of regular servicing from this. I'm grateful for you taking the time. I've had a similar experience dealing with a busted Corsa engine. Symptoms indicated it only needed a timing chain and a head gasket. It ended up with me also finding a piece of chain guide in the sludge sump, the camshaft lube holes were blocked and a fair amount of black silicone found circulating the system. Obviously some moron had been let loose with the silicone tube around the water pump and the inner bead had broken away during the water cycle, ended up being a full clean and rebuild. The take away from this is if you don't know the history of your engine, remove and clean the sump and change the oil every 5 - 6 thousand miles.

Congrats of 250k subs

This teardown was really interesting. Until the last few minutes, I would have thought this engine died of neglect. It was obvious from the moment you removed the valve cover that this engine had the bare minimum number of oil changes. I've never owned one of these engines, so I wasn't aware of the VANOS issue. I hope you have taken care of the VANOS on your S54. It's a ticking time bomb if you haven't replaced the pump disk on the exhaust camshaft. S54 engines also have problems with camshaft sprocket bolts. It's good to replace them at the same time as you replace the pump disk and seals in the VANOS unit. It would be great if you could get an S55. I'd really like to see a teardown of one.

hi man love your teardown`s ,keep up the good work all the best from the UK

It is the first so optimistic disassembling of BMW engine I have watched🙂

Funny, extremely entertaining guy.....never miss an episode

Cool engine this week! Love your videos! Still hoping you can tear down a 1.8 out of a 2016 Chevy Sonic, and a 2.4 SRT4 engine out of a 2003 PT Cruiser GT that has the aluminum intake setup on it. As usual another great video!

Great video Eric! Why do I love the sound of cracking torqued bolts? 🤔☺️

250K already! Congratulations.

I saw you on Rainmay Ray's channel. Nice that you get the nod from other channels. Keep up the carnage and the malice. We love your work!

The fuel injector area looks like a outboard motor that fell off the back of the boat and sat at the bottom of a lake for a while

Neat! An engine I've never worked on or seen inside of. Good stuff bubba

I love every single moment of this video. Watched every single moment even the waterpump toss.. Only disappointed a bit that lately was NO DISCONNECTING RODS... Greetings from Croatia!

Great video as usual. This is definitely a long shot as they're probably gonna be just about impossible to obtain one, but Nissan has a 1.5 3 cylinder with variable compression out in the new rogues. They have a bit of a problem with absolutely grenading themselves and coming in with a bunch of sludge in the oil pan. I'd be very interested to see you tear down one of those but they're going to be near impossible to find since they're almost all warranty jobs and Nissan wants them all back. Thanks.

I had an S54 and its was fairly trouble free. Maybe because I changed the oil every 3 months had it serviced regularly and gave the engine a proper warmup before pushing it hard . To be honest the only failure it had in 135k miles was an alternator.

Awesome video as always dude. Plus, I loved your mini-rant at the end about how you don't hate any particular brand, some people just can't handle the facts. As a car guy, I always say… "What car brand do I hate most? Which ever one I am under the hood of at the moment!!"

Keep up the good work Eric and the streams coming...

I own an import repair and performance shop. The amount of N55s that come in due to spontaneous engine failure is amazing to me. I still haven’t nailed down exactly why they fail, but a large number of them have suffered from a nasty rod knock. Some you can hear a faint knock from the bottom, and other it’s perfectly fine with no noises one day, and then next day the engine is completely seized up. It’s just strange because the N54 was pretty stout in comparison with fewer total reported engine failures.

The oil pump design was very interesting. More work when it fails, but it was pretty cool to see the thought process that went into the way this worked.

Thanks for showing us that oil pump action!

Eric , thank you so much for these videos.

I have 2011 n55 with 140k miles. Its been a pretty good engine. I just did rod bearings as preventative. Original bearings looked pretty good.

I wanna see another Ford 4.0L V6 but the OHV version (1991-2000). Love the Content Eric!

This channel is part of my weekend ritual now!

The rail set slam was the best part thanks Eric

I have a 2012 N55 (X3 3.5i) with 109K miles. So far I am happy with the N55. I change oil (Liquimoly) every 7,500 miles. I've changed the tranny fluid and pan, FR. and Rr diff fluid, the charge pipe cracked and replaced with metal one, RAD leaked on the drivers side plastic, replaced that, H2O pump replaced (what a crappy job), PCV diaphragm cracked and replaced the valve cover. I had the pleasure of paying for both Fr and Rr main seals as the PCV diaphragm failed in the manner where the seals were sucked in (mechanic did that job). Owned it for 9 years. Oil pan gasket still going...fingers crossed IMO, oil and fluid maintenance IS the difference to mitigate these major engine issues. Next month will send oil off to Blackstone for testing to get a glimpse into bearing wear

This engine is not in poor condition. It's in core condition

Very much enjoying your videos. Outstanding and well done. Went to a BMW Bimmerfest site to see what they were saying about the recommended oil change intervals. The information was that BMW changed the interval from 15,000 miles to 12,000 miles. That’s a lot of mileage between changes especially the way owners drive them. Maybe you could tell how miles between changes the owner of that engine went before changing the oil. Watching several of your videos. They are all great.

Another great teardown! The jokes were terrible as usual, I love it! See you on the next one!

All the N55s I have seen with spun rod bearings was from oil pressure loss and its usually cylinder 6 or 4.

Hello. Bmw dealer mechanic here. Here in the northern state of minnesota, when temps become very cold, these engines lock up on first start in the morning. It comes from lack of oil services, and moisture in engine. Every winter, we have a line of X5’s with seized engines

First time watching your videos, and it was a lot of fun seeing the process that you go through and the nice info that you provide, thank you.

"I hope it went in!" 'Nough said. Excellent and thank you, sir!

Had an n55 that the vanos failed and it caused a valve to break which then fell into the cylinder causing the engine to seize. All in about 45 seconds. Car had 90k miles.

Access to all the rod cap bolts is your MAIN concern. I see what you did there.

I'm not a mechanic, last engine i tore apart was 50 plus years ago, when they still looked like an engine and not an electrician's nightmare, But i love watching you tear these things down.

Unbelievable slow motion action shot!

I'm sure they saved a metric ton of weight by using all those aluminum bolts. I've always marvelled at the simplicity and effectiveness of eccentric rotor oil pumps; it's amazing how well they complicated that.

Best way to remove gaskets that are too hardened to scrape from aluminum are roloc finger discs, tho you need to protect the surrounding area from dust so I usually scrape the bulk first. The fine grit especially gives amazing control with varying pressure

Pleasure to watch,well done mate

Eric, you and your RU-vid Channel were mentioned a couple of times during by the man behind the Rainman Ray's Repairs RU-vid channel. Rainman Ray was diagnosing a strange sound in a Chrysler Pacifica Penstar V-6 Engine. He found some post factory installed inspection ports, a broken and bent connecting rod (with bearings that still looked to be thick enough to rule out oiling issues), and a cracked piston that showed signs of all four valves having made piston to valve contact. Although the video was dropped 8 days ago, I just found it around 4:00AM on Saturday 9/30/23.

I've had remarkably good luck with the N55. I've owned 2 of them and the only failure was a busted chargepipe. Mechanically, they were perfect, despite being tuned, overboosted and beat on.

Loved the video! Would love to see you tear down a 1UZ-FE, one of my fav Toyota engines!

Nice job buddy. Great video Eric.

You have a great business and I would love to work there, after 40 years of fixing them next October I would enjoy tearing them apart into a ton of little pieces like your company does. Good morning to you and enjoy your day today.

That last injector had a shake weight moment 😂

Little do people know, they changed the rod bearing formula in early 2013 due to bad wear conditions and the result of "bearing foil".

Well done on the 250k subs mate

Spun bearing and the dip stick have your number . But don't give up we love to see you work out.

As a previous owner of N55B30, you can get this amount of varnish and buildup even with very frequent oil change. It is caused by that plastic valve cover and built-in PCV valve

The N52/54/55/62 are a step forward and three steps back. Those aluminum fasteners and electric water pump make them a no go. Valve stem issues for N62

As someone quite new to understanding/working on the ins and outs of an engine, the top of mind knowledge is admirable my dude.

Little personal story about filter glitter... I rebuilt my Chevy 4.3 after coolant system failed and I drove it home with no coolant. I used the wrong parts and did not follow the torque specs, just kinda winged it. Heads, cam, and crank were resurfaced and bearings were only thing not reused. Sorta tried to port the oil system for better flow. Anyhow... first filter totally clogged with metal paste within 10 miles. 2nd clogged after a few hundred miles, filter brand definitely made a difference. 3 oil changes and probably a dozen filters all looked like a differential emptied into the pan. TONS of metal. Truck runs great, 50- 60 psi of oil pressure and probably about 5k miles since. No metal any more.

One thing that very few people understand is why the oil pump is a vane type instead of a gear type oil pump. The reason in this case is that it's allowed them to make it a variable displacement pump as in the quantity of oil being pumped changes so that the pressure can be constant regardless of rpm. The rotating assembly of the pump is held by a pivot on 1 side and a piston and spring on the other side and this is where the magic happens. Why run this style of pump instead of a gear pump? Because gear pumps are a compromise in sizing as they generally don't flow enough at idle and flow too much at rpm so the relief valve dumps the excess. These horsepower used to drive a variable displacement pump is far less than that required to drive a non-variable displacement pump.

Rod bearing failure in the early N55 platform is quite the common failure unfortunately. Lack of maintenance and in some cases improper clean care when replacing oil cooler seem to be the culprit. Proper oil intervals, cooling system maintenance (waterpump/thermostat/pretty much all other cooling system components), engine warm up time, and rain tray replacement if broken are just a few things one can do to extend N55 service life.

Not the first time I've seen one of those oil pumps on this channel. It's an eccentric vane-type pump with a variable displacement feature. Each of the vane-enclosed chambers gets bigger and then smaller as it goes around the shaft, thanks to the inner and outer rotors not rotating on the same axis (they're eccentric). The carrier for the outer rotor pivots such that the two rotors' rotating axes (center points of their circles) can get closer together. As they get closer, that bigger-then-smaller pumping action gets reduced, making the pump move less oil per rotation. The pivoting on the carrier is controlled by oil pressure working against the big spring. More pressure compresses the spring and makes the carrier pivot, reducing flow. If pressure drops, the spring pushes the carrier back, increasing flow.

One thing I've noticed about owning a BMW (X5/n55) is the forums and community is passionate and well informed on tech issues, I'm a 63 yr old long time mechanic and I find that's what I want since I like to do my own work, because all manufacturers make mistakes and at some they are going to pop up. Plus it can help you find a vehicle to stay away from.

The only proper way to deal with those timing chain guides 😂

Something I find a lot of people don't know about this engine when it comes to spinning bearings is the variable oil pressure design. There is a solenoid that looks like a vanos solenoid on the front near the crankshaft pulley. Their purpose is to reduce oil pressure at low RPM for more efficiency. These tend to wear out and react more slowly over time thus causing a rod bearing to spin. I just saw this happen on a guy i know with an f30 335i that had only 65k miles, also happened to be the #6 rod bearing. That in combination with BMW's insanely high oil change interval on these, sometimes 15000 miles, causes them to spin a bearing. N54s use the exact same rod bearings yet do not have this issue due to them not having this oil pressure control valve.

Love the way you went all Whistlin' Diesel on the cam chain tensioner.

🎶 The best part of Saturdays 🎵 🎵 Is the engine tear downs 🎶 🎶 That Eric does 🎵

After working on hundreds of N55s in my time, I've dealt with several complete failures. Nearly all of them were user error. It comes down to this only: Lack of maintenance kills N55s. Oil starvation kills N55s. Overheating kills N55s. Those are really the only "gotchas". You're responsible to keep an eye on your car. Let the car overheat and ignore the screaming dash warnings to shut it down and stop driving. Skip your oil changes, or let the level get too low. Find out what "break my wallet" really feels like. Yes, a few early cars had a known bulletin for this exact cam gear bolt issue. This one slipped through the cracks, and should have been addressed by the dealer. Otherwise, your N55 ownership experience will be above average in comparison to other turbocharged engines in this segment. general ownership aside, the N55 is an absolute marvel for it's time. It's a fabulous concept in comparison to some of the trash from the competitors. Yes, it is expensive. So are the cars it comes in.

Removing #1 and #6 at the same time....is that considered a reach around?

I have the S65 oil change at 4000 kms. Changed the rod bearings at 160,000kms.. Great engine maintenance

ID REALLY LIKE TO SEE A VIDEO OF YOU PUTTING AN ENGINE BACK TOGETHER.THAT WOULD BE SOMETHING TO SEE

In 10 years that plastic water pump will have the same part # as the turbo charger.

18:58 you could take out those springs and use them for mouse traps.

Absolutely amazing tear downs, Eric. I love it all - even the dad jokes! 😅. As for the N55 - so many rumours flying around, one of them being first generation(s) of N55 had weak bearings. Both your N55 tear downs must be early generation (pneumatic wastegate). The N55 you've had through your shop are they mainly early generation? (perhaps confirming the rumour). Anyway - keep 'em coming. We want more N55 😀