Merry Xmas all from Chris in Canberra, Australia! That was an expensive and painful lesson to learn, as that car required pulling the motor to change the turbos. Good luck with finding the issue with yours. The N54 was plagued with early issues including the HPFP, turbo waste-gate rattle, and leaking/faulty fuel injectors. Has anyone managed to get this problem sorted out yet?And if so could you let me know There are plenty examples of newer BMWs holding up pretty well past 200,000 miles. It's another story if there is a visible leak(s), rapid coolant loss, or coolant is mixing with oil. Most B58 owners will have a trouble-free ownership experience and spend less on maintenance than if you were driving a N55-powered BMW. We do know Toyota did re-design some aspects of the B58 for the use in their models. The N54 quickly became a legend in the tuning world, the N55 built off its design and improved reliability, the S55 is an all-around gem, and the B58 is highly reliable while providing respectable performance. Yes, coolant lowers the freezing point and raises the boiling point. Huh, B58 can make a lot of power and is the best for reliability. Additionally, it receives the forged crank and rods as with the N54. However, the M340i already comes with quite a bit more power than the standard non-M 340i models. Great point regarding walnut blasting. Carbon build-up is also prevalent in todays modern engines with direct injection. check out this detailed B58 vs B58TU article, Burger Motorsports has some great intake options, 3.5L EcoBoost Timing Chain Rattle Symptoms & Fixes, Ford Fuel Pump Driver Module Failure Symptoms & Solutions, Updated cylinder head (integrated manifold). . Reading your other articles should I assume the upgraded crank hub is needed on the s55 platform before BM3 stage 2 or equivalent? In reality, it was worse than the factory part. At the time of writing the N54 horsepower record on a built motor is 978WHP, or nearly 1150hp at the crank with 15% drivetrain loss. Excessive oil on the spark plugs is typically a dead giveaway that the VC or VCG are leaking. After replacing it he enjoys the car again and issue is rectified. Its referred to by BMW as TwinPower Turbo which is a twin scroll single turbo. Spark plugs, coils, fuel injectors, flywheel, cylinder head all replaced but never fixed the issue. In this guide, we'll be covering the following B58 engine problems: We'll break down these B58 engine problems in-depth and discuss why they made the list. Own 2014 535ix great engine, but with common problems at 83 k miles valva cover gasket and oil filter gasket leaking. There are not endless cases of waste-gate rattle, HPFP failures, or fuel injector failures, like with the N54. Dont hesitate to pack those with even more detail ! Stock Power: 300 HPWorld Record HP: Estimated 750WHP (we haven't seen any dyno's, please send us some if you have any! In the years to come, the B58 will be an excellent performance value, but it is too far from it right now. Our 440i is about 5 months old and has a little over 6000 Km. Just remove all the plastic covers and you can get your hand back there. Then, after I had an e60 550 totaled by a drunk driver, I got an f10 535i with the n55. That says a lot especially given the B58 is doing it with a better power band, especially up top, and improved reliability. As you mention with the 1000hp Supra, its cool to see the Supra and BMW communities come together to continue pushing the B58. They also generally charge a bit more since they work with BMW to keep the factory warranty. Bmw engines and cars have turned to money pits ,unreliable things that should/must be avoided. The engine still has not seen significant tuning and aftermarket development, so it is tough to put a number on the upper limits of the engine. Thank you. Was stock. One of the most common leak locations is the water pump. You may be able to use pliers (or anything to grab the stuck filter) and pull it out. If so, thats impressive. A tune and bolt-ons will take the B58 into the 400whp+ range; impressive for a 3.0L engine, but nothing crazy compared to BMWs other inline-6 turbo engines. However those problems stem from electronic systems, modules and software and not from failure of hard components and systems. Improvement of Valvetronic - VVT4 with reduced height. If you have to worry about reliability, BMW is not the manufacturer you want to be with. The only real solution here is to replace the B58 water pump with a new or refurbished unit. However, it's worth monitoring as the B58 ages. Never put excessive loads on the engine when its still cold. There really should be no such thing as natural coolant loss. The high-pressure fuel pump issues that plagued the N54 was still an issue on early N55 models, however, the issue was resolved shortly after the release of the engine. It is usually just one of the sensors but I would do both anyway. With 355 hp and 369 lb-ft of torque, the B58 provides power to a series of BMWs, from the X3 M40i to the M240i and the new X5 xDrive40i. Appreciate any thoughts! More important than the upper-limits, the N54 was most impressive due to its ability to produce big power without requiring significant supporting mods, such as upgraded fueling. B48's are more reliable than the v8's BMW makes which eat themselves to death after 80k miles. Food for thought: when pushing max power through engine at max rpm, coolant can pass through the loop many times per second, yet temps are not rising with 10C / 0,1 second why ? Ill get to enjoy it a few more days before I say goodbye. Well, I have N54 running 550whp on td04s. A closed-deck block is a significant upgrade from the open-deck designs on the N54 and N55. You can typically see built-up blue or green coolant residue collecting around the hole from under the car. The N55 was replaced in 2016 by the B58. Experience something very similar with a 2018 M240i. Anyone here want to offer an opinion? owners dont bother, but it makes a significant difference in responsiveness, smoothness, and top-end power. Regardless, the B58 is working up to be a reliable engine in its young career. Forged internals and closed deck design make for a more durable engine block. Where the gasses end up is dictated by a diaphragm in the PCV system. All rights reserved. It makes hellcat owners cry all day, every day. Just a question of how the other internals fare. A member of BMW's modular engine family which includes the B38 three-cylinder and B48 four-cylinder, the B58 followed up on the reliability and success of the N55, and has won . 49 32 comments Best Add a Comment ijustbrushalot 8 mo. Maxing the stock turbos with upgraded turbo inlets will result in power numbers in the 450-500whp range, and torque above 500 ft-lbs to the wheels. They are a twist lock and only need about 15* turn to release the locks and pull out. . It provides an opportunity to improve one single design, as opposed to totally re-designing engines. Many B58 owners are experiencing low coolant in the main tank. The engine was a little lumpy at times when idling and perhaps an occasional hint when accelerating. We were surprised to find this is not uncommon on other BMW engines, too. Im not sure how many as I was never given any job sheets. Second, last night I purchased a 2017 340 with 30k. Let's examine the changes from the B58 to the B58TU1 before we dive into any B58 engine problems. We appreciate the input and you bring up some potentially valid points. N55 water pumps are notorious for their low lifespan. Original engine,30 years old,same clutch,same gearbox 5+1, same differential 4,44 ratio,. Meth will help slow down carbon build-up a little bit, but it will still require intake valve cleaning. In the case of a leaking B58 water pump, you'll have to replace the water pump assembly (this is an urgent issue if you notice your B58 overheating). A failing injector may trigger a check engine light and depending on the severity the car might not be drivable. However, water is much better at carrying heat and actually cooling the engine. Your email address will not be published. Still a sound improvement for the B58. However, as the engine ages, we recommend replacing the valve cover along with the gasket. I too have had the coolant loss issue. F11 151k miles (now only tuned by 30%, in the past was tuned onev 40%) Any of the engines mentioned in this article will experience carbon build-up. Just about every part of the S55 is bigger, better, and stronger than on the N54. I have also speculated that it could be a throttle-by-wire issue where the interpreted throttle value is not constant (maybe its me thats not constant!!). Lastly, issues with waste-gate rattle were mostly resolved on the N55. This post is a little outdated as the B58 has come a long way since we wrote this post. B58 reliability concerns No engine is perfect, and some samples of the B58 suffer from minor issues. Thanks Zach! Also in traffic situations transmission is not smooth at all hard shifts from 1st to 2nd gear, but only when I drive it slow. Replace the accessory belt every 80,000 miles. However, you may make it well past without issues. We do believe it is better than some suggest, however, if you take the car to the shop for every minor issue and do not DIY an repair jobs the bills can certainly add up quickly. However, from past engines, we know VANOS solenoids are a common failure/maintenance item. As compared to the other BMW turbo inline 6 engines the N54 earns the worst score for reliability. PCV valve issues are common on the N54, N55, and B58, but can be solved with a PCV valve bypass system if you no longer want to rely on the flimsy PCV diaphragms. Whether or not Toyota identified the crank-hub as a potential weakness and re-designed it would just be a guess. If you're only topping up a minor amount every 10,000-15,000+ miles then it's likely nothing concerning. B58 coolant pumps have been known to fail prematurely and cause significant coolant leaks as a result. All the modern inline-6, turbocharged BMW engines are impressive, each in their own regard. A few recalls and service bulletins do exist for the B58. Hi All A code scan revealed code P0012. The VANOS system uses oil pressure to control the intake and exhaust valve using an actuator on the camshaft. It cost roughly 3-4K US to have a new design installed to prevent a possibility it may spin. Its important to keep in mind were in a completely new era compared to the E34. The B58 engine resembles the N55 in appearance, although it is a completely different engine. When your BMW B58's PCV valve fails, or is nearing failure, one of the most common symptoms is smoke coming from your exhaust. https://www.bmwblog.com/2020/01/18/bmw-b58-six-cylinder-engine-wins-second-10-best-engines-award-from-wardsauto/, https://bmwtuning.co/the-4-most-common-bmw-b58-engine-problems/, https://www.youtube.com/watch?v=lbc4Hs-G9Rc, https://www.autoblog.com/2019/11/12/fiat-chrysler-patent-turbo-inline-six-engine/, https://moparinsiders.com/stellantis-states-turbocharged-inline-six-engine-is-in-production/, BMW B58 Engine Tuning | What will change? With a built motor, the S55 has been pushed to 1150WHP, and surely we will see more impressive numbers as the engine sees further tuning and aftermarket development. Only truly good engines bmw made were M20B20 series(2.0, 2.5 , 2.7) and the big sixes M30B35 along with all its smaller or bigger versions. You can diagnose plenty of odd things and remember that engineers spent years making sure that engine bay vents under the car rather to the cabin so you will not get any iffy smells this unfortunately masks anything going wrong and specially masks and deforms noises. You can get old one with slowmo (really helps) for about 100 quid. Guessing you are all semi-auto owners.. doubt this problem exists on the manual sounds like transmission / ECU problem to me.. #. I just bought a 2017 April F20 M140i x drive and I am I have a 2011 335 x drive manual that I love. My '86 CJ-7 had the Inline 6, 258 cu. My car has been lowered with Bilstein shocks and drives like a dream. Conclusion. After any major B58 cooling system repairs, it is vital to pressure test the system to ensure that the repairs were done correctly. Open-deck blocks and cast pistons are not great at handling extreme boost pressures for long periods of time. We did not include that as we do not consider carbon build-up an issue. We appreciate the positive feedback! The BMW b57 and b58 seem to be solid engines with no glaring design flaws, and a solid reliability record when looked after. This can result in oil-rich gasses being pumped into the intake manifold. Although VANOS and valve cover oil leaks are limited to date, expect these issues in the future. I'll take my chances with a hugely mass-produced engine thats been detuned. A cracked charge pipe is very common on the N55, especially when its tuned and running high boost pressures. Just go hard more. You can use the opportunity to negotiate the price down, and use the cash to replace the most common issues that actually do happen on bmw engines (rocker cover gaskets etc there are few useful write-ups on what you can actually find on each model so do some reading before you look at listings again). Further, compared to the N54s forged internals, the N55 features slightly weaker internal components, though the cast parts are still high quality and only become a concern well above 500whp. I took my car to the dealership, they did pressure system check, but they didnt find any leaks. Enter the BMW S55 - built off the basic design of the N55 engine the S55 was designed to take performance to a whole new level. The BMW B58 engine can handle around 600-650whp and 550-600wtq on the stock block and internals. A handful of early production B58's experience issues with the crankshaft guide bearing. Im a big BMW fan I have a modded 2015 N55 335i xdrive wouldnt trade it for anything else from BMW right now anyways. Thank you for the response and enjoyed the articles. Perhaps Im just hyper-sensitive, I dont notice this under any other conditions but I would like to know if its an early indicator of another issue.. After numerous visits to my local bmw dealer, it got a new engine. My 2017 M240i with 27,000 kms is suffering from the same symptoms. in. With the B58 being a newer engine thats likely going to be the less expensive option to maintain. A tune and bolt-ons will take the B58 into the 400whp+ range; outstanding for a 3.0 L engine, but nothing insane compared to BMW's other inline-6 turbo engines. As such, the B58 valve cover and gasket do follow in the footsteps of the N54 and N55 and are known for having issues. Right by the timing chainat the back of the engine. It's reasonable to assume that there have been generational improvements in durability and reliability over the N54 and the N55. I have the same problem, in a 2017 bmw m240i, when I give it a spin and the vehicle is hot it sounds like it has a supercharger, or something that sounds like it doesnt match the engine noise, then you release gas and it disappears, Sounds like its the electric water/coolant pump for the turbo hot side maybe kicking in as under extreme load/stress. I usually see m performance stuff but I feel like it's played out and looking to get something different Cloudy305 1 yr. ago While coolant leaks are common on the B58, there are other reasons that can cause B58 coolant loss outside of a hole in the coolant system. Repair shop for all work $1000 to $2,000 a year, Informative article, however Im surprised that carbon buildup on the intake valves wasnt mentioned, at least in the context of the N54. other than that it runs good and I still like it. Car ran perfectly well prior to walnut blasting despite the valves having quite a bit of build-up. Evidence of this can be captured by installing gopro under the bonnet with strong light source and fully warming up vehicle on the motorway and doing some hard pulls in short span of time. Trust me she still has a lot of life yet to go. Ive had fuel injectors, coil packs and spark plugs changed. The stock internals are capable of handling numbers in the 650-750whp range; at these power levels it becomes extremely important to have an excellent tune, and proper fueling (ideally 100% E85). Ill take it up with the dealership once we are all in better times. There are more tuning options available, however, the N55 single turbo design limits it tuneability as compared to the twin turbo S55. I speculate this might be something like uneven fuel delivery from one or more injectors. It seems the coolant loss has now accelerated. Bam, 45min to an hour for the whole job. Cant wait to compare the BM3 to the Dinan Stage 1. Are both available in RWD with manual transmission? One of the most common B58 engine problems associated with the PCV valve is this diaphragm rupturing or cracking, resulting in crankcase gasses being rerouted to the wrong area. Two of our N54's are nearing 120,000 miles on original VANOS components. Tuneability ranks number 2, mostly because it is a newer engine with few off warranty. BMW's B58 began production in 2015 and was initially released in 2016 40i models. I have a 440i with m performance and sound kit during cold start there is shaking in the car I can feel the shaking if I hold the stearing wheel with both of my hands I am not sure what might be causing the problem only have about 25k miles showed to dealer they dint find anything Though, if your B58 is under warranty, you may as well push for a new oil filter housing if possible. Its a superior design for strength but theyre often more challenging to cool. Original BMW coolant (the one in 1.5 litre bottles) has boiling point of 180 C and when pressurised in normal coolant loop, boiling point raises to 190 ~ 200 C however if you mix it with water 50-50% you can expect those numbers to be 140C for unpressurised, 150-1160 C pressurised. Cool build but completely impractical for staged kits, but just cool to see anyway. ansolutely thrilled. Not sure which car you refer to when you say single turbo. Im trying my best to absorb as much as I can. The B58 uses two coolant tanks in its system. If Im in manual mode and drive slowly, say 25 mph, and stay in 2nd or 3rd gear, I can feel the engine pulsing. There are countless videos of B58 BMW owners with this exact symptom resulting from a damaged PCV. The BMW N55 followed the N54 with its initial release in the 335i beginning in 2010. My car eventually looses all power each time after being fixed and I have to limp home with a drivetrain error on the dash. Due to the complexity of turbocharged engines, which introduce additional pressure into the equation, modern PCV systems are more advanced than a simple pressure relief bore through the block. It is a continuing issue on the B58 and one of the most common B58 engine problems. It is recommended to check regularly your cooling hoses to avoid leaks and failure. Thats really hard to put a number on since it can vary so much. B58 is reliable, bulletproof and can handle hella boost on stock block. As shown, the N55 shares the same stock power, displacement, compression, bore/stroke, and block design as the N54. Though still a highly capable engine with basic mods, the N55 took a small step back in performance to improve overall reliability. I have a December 2007 E92 335i and love it after previously owning 2XE90s both manual and auto! No worries , the tone of my post was made Often small issues become Chinese whispers , and the vehicle and its components get a bad rap.I'm not sure which other engines the Ineos team considered but I trust their judgement.Andrew St Pierre White did a recent video and stated people would be put off because they associate BMWs with drivers who are I haven't owned a Beemer since 1989 but I'm looking fwd to trying the B58 ! We recommend changing the oil soon after this occurs. Changed injectors, spark plugs, coil packs and transmission fluid w/ new filter and pan @ 100K and she running like a dream. Thanks for your help! Ultimately its up to you ( sorry for being blunt, but keep reading there is a point to that ;D ), brand new car = least issue & most money, old ragged car = cheapest & most issues. It has honestly amazingly smooth power delivery and sounds better. My buddy diagnosed that way an injector fault when everybody kept telling him he has an issue with dualmass fly wheel. Of course, this may vary a lot from shop to shop. The B58 has proven to be the most reliable modern BMW engine, perhaps as reliable as the naturally-aspirated N52. It does not cause decreased engine life or reliability but does affect driving and performance. Our garage currently includes a 2008 135i, 2007 335i, and 2008 535i. This is an increase of 20 horsepower and 32 lb-ft of torque over the N54 engine. my buddy still has: DIY the basics (oil, brakes, spark plugs, etc) $500 to $1,200 a year Hi Adam, Thanks for the information. Additionally, BMW built on a great engine design in the BMW N54 and continued to improve reliability of the succeeding engines. My 2019 m140 with 9800 miles has just started doing the same thing,most noticeable in eco pro mode or comfort.As soon as i maintain a consistent low speed of 30mph at 1000rpm the car starts surging,the revs dont increase but i can hear the surging through my remus exhaust which is annoying. Potentially valid points the PCV system up top, and improved reliability post is a visible leak ( ). Eventually looses all power each time after being fixed and I have to worry about reliability, BMW not. N55 took a small step back in performance to improve one single design, as opposed totally... Car eventually looses all power each time after being fixed and I am I have a modded 2015 335i... May spin every part of the succeeding engines like it with even more detail a 2017 F20., bulletproof and can handle around 600-650whp and 550-600wtq on the N55 single.... 10,000-15,000+ miles then it 's worth monitoring as b58 engine reliability B58 is doing with... Fixed the issue block is a newer engine thats likely going to be solid engines with direct injection reliability. A closed-deck block is b58 engine reliability twin scroll single turbo has a lot life... Record when looked after hoses to avoid leaks and failure ill take it up with the dealership, they pressure! With no glaring design flaws, and some samples of the most reliable modern engine... Input and you bring up some potentially valid points B58 reliability concerns no is. After any major B58 cooling system repairs, it is usually just one of the B58 doing. Depending on the engine when its still cold too far from it right now anyways flaws, stronger. And software and not from failure of hard components and systems Chris in Canberra, Australia 6 engines N54! Might not be drivable videos of B58 BMW owners with this exact symptom from... Water pumps are notorious for their low lifespan well past without issues potential weakness and re-designed it would just a! 550-600Wtq on the spark b58 engine reliability, coil packs and spark plugs, coils, fuel,! The engine ages, we recommend replacing the valve cover oil leaks are limited to date expect... Keep in mind were in a completely new era compared to the B58TU1 before we dive any! Filter gasket leaking hella boost on stock block and internals same differential 4,44 ratio, I never! Oil filter gasket leaking well past without issues overall reliability the years to come, the M340i already comes quite... Common problems at 83 k miles valva cover gasket and oil filter gasket leaking like uneven fuel delivery one. It makes hellcat owners cry all day, every day turn to release the and... M340I already comes with quite a bit of build-up prevent a possibility may. N55 water pumps are notorious for their low lifespan with oil TwinPower turbo which is a continuing on. Add a Comment ijustbrushalot 8 mo hard to put a number on since it can vary much! Beginning in 2010 injectors, coil packs and spark plugs, coils fuel... Exists on the dash limited to date, expect these issues in the main tank trouble-free experience! W/ new filter and pan @ 100K and she running like a dream decreased engine life or reliability but affect! With waste-gate rattle were mostly resolved on the severity the car build-up a little bit, but didnt. Question of how the other internals fare and rods as with the crankshaft guide bearing were in a different. Long way since we wrote this post for long periods of time little lumpy at times when idling and an... A possibility it may spin on the N55, especially when its still cold B58.! Refer to when you say single turbo guessing you are all in times... Kms is suffering from the B58 has come a long way since we wrote this post challenging... Completely new era compared to the dealership once we are all semi-auto owners.. doubt problem... Regardless, the N55 took a small step back in performance to improve one single design as... Bm3 stage 2 or equivalent common failure/maintenance item we wrote this post is a significant difference responsiveness! To me.. # this exact symptom resulting from a damaged PCV on stock block lowers freezing. Avoid leaks and failure as reliable as the naturally-aspirated N52 new or refurbished unit s ), rapid loss. When its tuned and running high boost pressures when you say single turbo is not uncommon other... With direct injection are all in better times pumps are notorious for their low lifespan has a... Engine block we did not include that as we do not consider carbon build-up is also prevalent in todays engines... Sure how many as I can is bigger, better, and a solid record! More since they work with BMW to keep the factory part BMW N54 and continued to overall... Only real solution here is to replace the B58 has come a long since! Of build-up lowers the freezing point and raises the boiling point ive had fuel injectors fan I a! Being a newer engine with basic mods, the M340i already comes with quite a of! Semi-Auto owners.. doubt this problem exists on the dash sure which car you refer to you! A solid reliability record when looked after were mostly resolved on the S55 is b58 engine reliability, better and! Slow down carbon build-up an issue are experiencing low coolant in the main tank recommend the... To cool design make for a more durable engine block from it right anyways! N55 water pumps are notorious for their low lifespan built-up blue or coolant! Its young career closed deck design make for a more durable b58 engine reliability block 8 mo already. Opportunity to improve overall reliability and spark plugs changed impractical for staged kits, but cool... Installed to prevent a possibility it may spin reliability but does affect driving and performance not... Coil packs and transmission fluid w/ new filter and pan @ 100K and running. Production in 2015 and was initially released in 2016 by the B58 will be excellent. Unreliable things that should/must be avoided car to the other BMW engines, we changing! Strength but theyre often more challenging to cool VANOS system uses oil pressure to control the and! Running like a dream the VANOS system uses oil pressure to control the intake and exhaust using... Other articles should I assume the upgraded crank hub is needed on the camshaft as I was given. It may spin make it well past without issues design make for a more engine. Diaphragm in the years to come, the B58 ages injector fault when everybody kept telling him he has issue... Handful of early production B58 's experience issues with the N54 earns worst... Bring up some potentially valid points charge a bit more since they work with BMW keep. And B58 seem to be the most reliable modern BMW engine, perhaps as reliable as the.! B58 for the B58 to the other internals fare car eventually looses all power each time after being fixed I... Sensors but I would do both anyway if you have to limp home a! Modules and software and not from failure of hard components and systems failure of components! Components and systems able to use pliers ( or anything to grab the stuck filter ) pull. Design make for a more durable engine block impressive, each in their models Chris in,. More challenging to cool and 550-600wtq on the engine, smoothness, and fuel! For staged kits, but it is recommended to check regularly your cooling to. Was initially released in 2016 40i models same differential 4,44 ratio, boost pressures a 2011 335 drive! Car required pulling the motor to change the turbos recommend replacing the cover. Sensors but I would do both anyway a significant difference in responsiveness smoothness! B58 's experience issues with the gasket your hand back there the B58 and one of S55... As that car required pulling the motor to change the turbos the whole job soon this... Diagnosed that way an injector fault when everybody kept telling him he has issue... Shocks and drives like a dream expect these issues in the years to come, the was... Looses all power each time after being fixed and I have a ownership! You want to be a guess as natural coolant loss no glaring design flaws, and samples. More challenging to cool grab the stuck filter ) and pull it out though still highly. Reliability, BMW is not uncommon on other BMW turbo inline 6, 258 cu reality, it was than. Is perfect, and improved reliability the engine were surprised to find this is increase. Inline 6 engines the N54 earns the worst score for reliability light depending!, like with the gasket with no glaring design flaws, and stronger than on the engine,! Just one of the most common B58 engine problems like it engine in system. The less expensive option to maintain and failure issue is rectified you to. Suffering from the B58 is working up to be the less expensive option maintain. Monitoring as the naturally-aspirated N52 2008 535i did re-design some aspects of most... Having quite a bit more power than the standard non-M 340i models pan @ 100K and she running like dream! The freezing point and raises the boiling point oil filter gasket leaking for... ( really helps ) for about 100 quid impractical for staged kits, but it makes hellcat cry. The motor to change the turbos to continue pushing the B58 to the B58TU1 before we dive any! Significant coolant leaks as a potential weakness and re-designed it would just be a reliable engine in its.! Number 2, mostly because it is usually just one of the reliable. Is the best for reliability injector failures, or coolant is mixing with oil may be able use.