• BMW 2.0 liter four cylinder N20 turbo motor already having issues? Head cracks under stress above 331 pound-feet of torque?

      Some interesting information was posted in the N20 section of the BimmerBoost BMW forums regarding the durability of the N20 motor. Now, the motor is becoming very popular and is winning multiple awards and rightfully so as it is currently the best factory 2.0 liter turbo four cylinder in production. The keyword there being factory as apparently it is not going to be a stout aftermarket tuning platform at least not yet. Take the information you are about to read as unconfirmed but from an interesting source.

      There are companies that stress test engines for OEM's. One of these companies has been testing the N20 apparently. The advice given is not to go beyond Stage 2 on the N20 which means a slightly more aggressive tune on the factory turbocharger. Why? The N20 head apparently cracks at around 331 pound-feet of torque. That is not exactly a whole lot of torque in the turbo tuning game especially considering the motor puts out an underrated 258 pound-feet from the factory.

      Apparently the engine is just running very hot and multiple heat cycles are creating problems. BMW behind the scenes is supposedly trying to correct the issue. For whatever reason BMW seems to have a reputation for problems with new motors. S54 bearings, S65 bearings, and the next BMW new motor issue looks to be the N20 head cracking.

      The story is that one of the lead designers and engineers for the N20 was flown out to the USA to inspect the findings for himself. It is doubtful BMW would do that unless there was something of substance to this. This same company also apparently tested other BMW motors including turbo motors such as the N54 and N55 when they were new and they did not run into these head issues.

      So what is going to happen? Well, right now it is not recommended for N20 owners to push their motors too far which they can't anyway as there are not aftermarket turbo options out just yet. BMW will likely resolve the problem with a new head which will mean for those with the N20 there will either be a recall or there will be a BMW part number option to get the new head. We will have to wait and see what happens but N20 owners should be aware of the potential issue especially if intending to tune as BMW is unlikely to say anything until they have to.

      This article was originally published in forum thread: N20 Owners started by VargasTurboTech View original post
      Comments 163 Comments
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        We're running ours at 300whp / 350wtq (dynojet) and so far it's running well. Will throw a larger turbo on it as soon as its available so we can see if there is any truth to that! Click here to enlarge
        T, some guy in russia was claiming 463WTQ and 358 WHP (on your Software so I am sure you know) thats well above what the guy above is claiming as the limits. I ordered some parts for the turbo, not exactly sure how long they will take, but hopefully not too long. Soon as its done, Ill send it to you and you can send me your core back. See what that baby can do.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by VargasTurboTech Click here to enlarge
        T, some guy in russia was claiming 463WTQ and 358 WHP (on your Software so I am sure you know) thats well above what the guy above is claiming as the limits. I ordered some parts for the turbo, not exactly sure how long they will take, but hopefully not too long. Soon as its done, Ill send it to you and you can send me your core back. See what that baby can do.
        Lot of Russians full of $#@! with dyno numbers as of late.
      1. klipseracer's Avatar
        klipseracer -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Lot of Russians full of $#@! with dyno numbers as of late.
        In Russia, horsepower dynos itself.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by klipseracer Click here to enlarge
        In Russia, horsepower dynos itself.
        Click here to enlarge
      1. Charrigan's Avatar
        Charrigan -
        Click here to enlarge Originally Posted by George Smooth Click here to enlarge
        More often than not the R&D guys use one off turbos for different testing. The first N54 test mule was a single turbo.
        This was his exact answer to me. They are supplied multiple turbos and injectors that can safely flow these higher power levels. Bmw does not give them turbo specs. They are testing the engine block/heads amd all the internals not the external components. They dont even use the oem hpfp's. they have an external unit that can run fuel on a DI engine. They only test on engine dyno's and follow what bmw or whoever else wants to test at. They are modified stock turbos on the n20 they are testing and bmw supplied them with the engines. As far as the n54/n55 bmw again supplied them with modified larger turbo/s. bmw specifically had them do longevity tests at 450-500hp. They (the engine testers) wanted to see how well a few would handle the higher hp and nothing broke. The new m3 will be near those hp marks so maybe this was their way to find weakness in the n54/55 to build a better next gen M engine.
        Click here to enlarge Originally Posted by VargasTurboTech Click here to enlarge
        Ok thats all well and good, so if this guy is such good friends with said testers, then what turbo / turbos were they running? And there already people making more then those numbers he claims are fail point and have been doing so for a while and the engine has been fine. As I said, still calling bs on this. BMW is not going to produce a motor that fails at those levels, that is my opinion, and is just that opinion. But until he can tell us some more details, what he is saying doesn't really add up.
        Call BS all you want. I see threads and hear people talking up the N20 on all othe bmw forums like its the next n54 freak engine that can handle crazy power. In the end it's not. If you read back I never said they will fail at those levels right away like everyone thought I implied. They put these engines through some extreme stress and pretty heavy heat cycling. He even said he would feel safe on a n20 at those power levels for ~100k miles. It's unknown how long it will last beyond those levels in terms of reliability. Sure you may make 400lbft but for how long?
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        I think some good points are being made....how can they run a n54 to 600+ hp on stock turbos? Hmmm. If they did swap out turbos to run up the hp, why would they even do this? They would have to make a lot of changes just to make it work.... I call bull$#@! also
        Read above. Every forced induction engine they test weather it's GM, bmw, ford, or vw. They test at much higher than stock power levels. This helps them find failure points much earlier in their engine cycles and gives assurance of the long term reliability of the engine. I guess take what I say with a grain of salt. This was told to me by a real engineer within the FEA testing world. He has no reason to lie to me and I have no reason to lie. If its felt that strongly it's BS then delete all my posts. Again I posted this info to just be a soft warning to the current and potential n20 owners with thoughts of going crazy on it. The n20 is and always will be an entry level engine and bmw has no reason to overbuild it and increase the engine cost to handle 100% over stock power. On the other hand the n54/55 was intended from the get go to eventually go in M cars due to fuel economy requirements, and would put them back in the game against their competitors. Overbuilding the n54/55 is in their better interests.
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by Charrigan Click here to enlarge
        This was his exact answer to me. They are supplied multiple turbos and injectors that can safely flow these higher power levels. Bmw does not give them turbo specs. They are testing the engine block/heads amd all the internals not the external components. They dont even use the oem hpfp's. they have an external unit that can run fuel on a DI engine. They only test on engine dyno's and follow what bmw or whoever else wants to test at. They are modified stock turbos on the n20 they are testing and bmw supplied them with the engines. As far as the n54/n55 bmw again supplied them with modified larger turbo/s. bmw specifically had them do longevity tests at 450-500hp. They (the engine testers) wanted to see how well a few would handle the higher hp and nothing broke. The new m3 will be near those hp marks so maybe this was their way to find weakness in the n54/55 to build a better next gen M engine. Call BS all you want. I see threads and hear people talking up the N20 on all othe bmw forums like its the next n54 freak engine that can handle crazy power. In the end it's not. If you read back I never said they will fail at those levels right away like everyone thought I implied. They put these engines through some extreme stress and pretty heavy heat cycling. He even said he would feel safe on a n20 at those power levels for ~100k miles. It's unknown how long it will last beyond those levels in terms of reliability. Sure you may make 400lbft but for how long? Read above. Every forced induction engine they test weather it's GM, bmw, ford, or vw. They test at much higher than stock power levels. This helps them find failure points much earlier in their engine cycles and gives assurance of the long term reliability of the engine. I guess take what I say with a grain of salt. This was told to me by a real engineer within the FEA testing world. He has no reason to lie to me and I have no reason to lie. If its felt that strongly it's BS then delete all my posts. Again I posted this info to just be a soft warning to the current and potential n20 owners with thoughts of going crazy on it. The n20 is and always will be an entry level engine and bmw has no reason to overbuild it and increase the engine cost to handle 100% over stock power. On the other hand the n54/55 was intended from the get go to eventually go in M cars due to fuel economy requirements, and would put them back in the game against their competitors. Overbuilding the n54/55 is in their better interests.
        you know what I'm hearing, the same record being played everytime a new BMW motor comes out, it was tested its gonna break here, oh wait, no here! Oh wait no here!!! N54 had the same story. It now sits over 700 on the stock block. Show us some proof, so he has no idea what the turbos were, they just bolted sonething up to it and away they went 650 hp. I also had a beer with big foot last night. But I forgot the name of the bar he hangs in.
      1. inlineS54B32's Avatar
        inlineS54B32 -
        I have a friend (acquaintance) that works at BorgWarner in Chicago doing stress testing/failure analysis... I have not personally witnessed him doing this, but he claims that manufacturers do send them motors to find the failure points. I think there are two sides to this coin - I think people are hearing "X HP/ft-lb is the failure point of the N20" and not believing it because someone hit that number already in the tuning scene. On the other hand - there is a HUGE difference between running full load for a few minutes a day - and a few hours a day. I think that's the difference - these guys are trying to destroy an engine. Most sane individuals don't try to do this to their own cars. Click here to enlarge

        Take it with a grain of salt as they say, I have no idea about how BMW tests their stuff, just know what I have heard in regard to other manufacturers.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Charrigan Click here to enlarge
        This was his exact answer to me. They are supplied multiple turbos and injectors that can safely flow these higher power levels. Bmw does not give them turbo specs. They are testing the engine block/heads amd all the internals not the external components. They dont even use the oem hpfp's. they have an external unit that can run fuel on a DI engine. They only test on engine dyno's and follow what bmw or whoever else wants to test at. They are modified stock turbos on the n20 they are testing and bmw supplied them with the engines. As far as the n54/n55 bmw again supplied them with modified larger turbo/s. bmw specifically had them do longevity tests at 450-500hp. They (the engine testers) wanted to see how well a few would handle the higher hp and nothing broke. The new m3 will be near those hp marks so maybe this was their way to find weakness in the n54/55 to build a better next gen M engine. Call BS all you want. I see threads and hear people talking up the N20 on all othe bmw forums like its the next n54 freak engine that can handle crazy power. In the end it's not. If you read back I never said they will fail at those levels right away like everyone thought I implied. They put these engines through some extreme stress and pretty heavy heat cycling. He even said he would feel safe on a n20 at those power levels for ~100k miles. It's unknown how long it will last beyond those levels in terms of reliability. Sure you may make 400lbft but for how long? Read above. Every forced induction engine they test weather it's GM, bmw, ford, or vw. They test at much higher than stock power levels. This helps them find failure points much earlier in their engine cycles and gives assurance of the long term reliability of the engine. I guess take what I say with a grain of salt. This was told to me by a real engineer within the FEA testing world. He has no reason to lie to me and I have no reason to lie. If its felt that strongly it's BS then delete all my posts. Again I posted this info to just be a soft warning to the current and potential n20 owners with thoughts of going crazy on it. The n20 is and always will be an entry level engine and bmw has no reason to overbuild it and increase the engine cost to handle 100% over stock power. On the other hand the n54/55 was intended from the get go to eventually go in M cars due to fuel economy requirements, and would put them back in the game against their competitors. Overbuilding the n54/55 is in their better interests.
        I like what you wrote but completely disagree that the n54 and n55 were built woth m's in mind. The n54 came out before the s65 and was entry level as well. Just because it's head doesn't crack doesn't mean it's built for big hp. It just keans it's not defective.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by inlineS54B32 Click here to enlarge
        I have a friend (acquaintance) that works at BorgWarner in Chicago doing stress testing/failure analysis... I have not personally witnessed him doing this, but he claims that manufacturers do send them motors to find the failure points. I think there are two sides to this coin - I think people are hearing "X HP/ft-lb is the failure point of the N20" and not believing it because someone hit that number already in the tuning scene. On the other hand - there is a HUGE difference between running full load for a few minutes a day - and a few hours a day. I think that's the difference - these guys are trying to destroy an engine. Most sane individuals don't try to do this to their own cars. Click here to enlarge

        Take it with a grain of salt as they say, I have no idea about how BMW tests their stuff, just know what I have heard in regard to other manufacturers.
        Best post so far.
      1. bobS's Avatar
        bobS -
        I knew sticky would strongly disagree about the n54/n55 being built for m cars! Lol. ...yet, the new m will have a variation of that engineClick here to enlarge

        The strong marketing mind of BMW may have thought the e9x was to early for a 6 cylinder turbo, since all thier competitors had v8's.... Meh, who knows

        @Charrigan at least tell us the company he works for, if you can. And also tell your buddy they blew it with the hpfp, they should have found the early ones sucked!
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        I knew sticky would strongly disagree about the n54/n55 being built for m cars! Lol. ...yet, the new m will have a variation of that engine
        If it's built like the N54 I will probably break into tears and just move on from BMW forever.
      1. bobS's Avatar
        bobS -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        If it's built like the N54 I will probably break into tears and just move on from BMW forever.
        Why? What's wrong with the n54?
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        Why? What's wrong with the n54?
        Absolutely nothing, guy has a hard on for hating a motor that is proving to be pretty amazing. But hey he likes V8's...Click here to enlarge
      1. lulz_m3's Avatar
        lulz_m3 -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        If it's built like the N54 I will probably break into tears and just move on from BMW forever.
        Such a hater. Go Heat.
      1. bobS's Avatar
        bobS -
        Click here to enlarge Originally Posted by VargasTurboTech Click here to enlarge
        Absolutely nothing, guy has a hard on for hating a motor that is proving to be pretty amazing. But hey he likes V8's...Click here to enlarge
        I agree.... Good thing BMW doesn't have a ego about v8's.... Btw the m3 has always been inline engines, 4, 6's. There were many that hated the idea of a v8, I remember the complaints before the e9x came out...
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        I agree.... Good thing BMW doesn't have a ego about v8's.... Btw the m3 has always been inline engines, 4, 6's. There were many that hated the idea of a v8, I remember the complaints before the e9x came out...
        In my personal opinion an I6 is the engine that belongs in the M3 its the motor I think of when I think M3.
      1. hkninja's Avatar
        hkninja -
        Click here to enlarge Originally Posted by VargasTurboTech Click here to enlarge
        In my personal opinion an I6 is the engine that belongs in the M3 its the motor I think of when I think M3.
        Well, the next M3 is going to be 6cylinders so its all good! I heard it might be tri-turbo as well????
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by hkninja Click here to enlarge
        Well, the next M3 is going to be 6cylinders so its all good! I heard it might be tri-turbo as well????
        Lets hope not. Sounds like a nightmare to me.. haha
      1. bobS's Avatar
        bobS -
        I doubt it will be tri turbo...
      1. Itsbrokeagain's Avatar
        Itsbrokeagain -
        Hm interesting. Lets see where the N20 takes us! If it indeed cannot handle much hp ill just get one to putter around in