How To Make BMW’s Notorious N54 Engine More Reliable

I remember the shock, the screams, the pitchforks. It was 2007 and BMW just unveiled its very first twin-turbocharged automobile at any time, the N54-powered 335i. Regional villages ended up currently being barbecued although BMW admirers screamed about turbo lag and the impurity of having exhaust-pushed turbines. These days, that very same automobile and engine is coveted for its strength and electric power possible in a planet of little turbocharged engines. But it is really also criticized for being a revenue pit. The good thing is, although diehards were crying about turbos, other fanatics embraced the modify and employed those  15 decades to determine out how to make these automobiles reliable … mostly.

A rapid listing of BMWs you’ll obtain the N54 inline-6 motor in:

Ok, I may possibly be exaggerating a little bit about that initial response. But the very long-phrase dependability of individuals early turbo BMWs has been bad. The common difficulties are aplenty. There is an oil leak that will cause belts to slip, which triggers the front most important seal to are unsuccessful, which clogs the oil pickup with rubber, thereby starving the motor of oil and blowing the engine. The reducing-edge piezoelectric gasoline injectors (intended for European styles that lean-burn up, not for us in the U.S.) have a inclination to stop injecting fuel, as does the high-strain fuel pump. Valve handles crack and leak. The twin Mitsubishi TD03 turbos explode with regularity, and the wastegates rattle. 

I desire I could say all those had been all the problems that plague these products, but the truth is that the N54 is a deeply flawed motor. It was only just not long ago that the aftermarket has at last caught up and tackled most of its main problems. Contacting it “trustworthy” now could possibly still be a stretch, but I can say I would attempt to have a single once more with these components. Let’s dig in. 

Turbocharger failures and BMW N54 could as very well be synonymous. The turbos on their own can last fairly a although, but it would seem that nearly each and every N54 with stock models has an frustrating wastegate rattle. Commonly, the rattle precludes the doom of the center housing rotating assembly (CHRA), but it can be fixed on its very own thanks to Vargas Turbo Technologies (VTT).

It is an concerned take care of that does include removing the turbos, an endeavor that requires the removing of the front subframe. But it is a superior possibility to use VTT’s wastegate mend kit if the turbos are kosher. It is composed of a new wastegate flap, arm, and press-in bushing that gets rid of the rattle completely. 

If it were being me likely by means of the hard work of eliminating the turbos, I’d save up a bit for a longer period and get entirely clean turbos to help save myself any long run difficulty. The problematic inventory turbos can be effortlessly replaced by an array of aftermarket upgraded twin turbos that mount like the factory pieces or completely replaced by a much more productive single turbo. It all is dependent on emissions specifications in the point out where the automobile is registered. For myself in California, stock-searching twin turbos can assist me get by.

A one turbo kit would be the perfect matter to do, but it would make the car or truck quickly unlawful in many states. It’s less difficult, much better at generating electrical power, and is a great deal a lot more reliable. The catch is that a respectable setup will price north of $7,000. That would make a $2,000 set of upgraded twin turbos seem to be like a deal. A wide variety of businesses make drop-in kits, like Pure Turbos, CTS, and VTT. My selection would be the VTT kit that has the wastegate repair pre-mounted and has electrical power-introducing upgrades, all for roughly $1,000.

These engines may well be the most leak-inclined of nearly anything article-’00. No, very seriously. The undoing of any N54 will be the fact that it leaks oil relentlessly. The only way to take care of that is a laundry checklist of gaskets, all at when. With no new gaskets, you threat blowing the motor by the aforementioned belt slip concern and/or a seriously stained parking house. Then there is the problem of the explosion-inclined drinking water pump and digital thermostat.

The manufacturing unit gaskets that succumb to the heat are the oil pan gasket, oil cooler gasket, oil filter housing gasket, front major seal, and valve deal with gasket. FCP Euro has useful kits for these work opportunities (oil filter housing and oil cooler, oil pan) and delivers a lifetime warranty. Undertaking the oil pan gasket demands the removing of the front subframe a lot like the turbos and like a possible drinking water pump job. In point, most of the common repairs that happen to an N54-powered vehicle need a subframe removing, so it turns into a person significant when-you are-in-there situation. 

Commonly, the only reason the front main seal fails is since of oil-saturated generate belts slipping off of the pulleys and reducing it. VTT has also created a resolution to stop that with a defend for the front key seal that helps prevent catastrophic failure when (not if) oil leaks on to the belt. As for the valve include, those can be problematic with cracks that cause oil leaks as a substitute of the gasket itself. VTT also has a resolution for this in the kind of an aluminum valve protect and re-engineered gasket set for around $700. The manufacturing unit BMW plastic valve deal with is $529.

For the final spherical of stage zero mods, a new h2o pump and thermostat package will bring about an additional $689 to disappear from your lender ledger. It’s high priced but it helps prevent a headache in the extended time period, specifically on an engine-significant component.

While surely not the very last weak point of the N54, fueling is the last of the major ones to address in advance of I could have the self-confidence to road journey the auto. The primary problems are the fuel injectors and the higher-stress fuel pump. Both of those have been notorious difficulties at the really start out of generation and can however chase house owners to this day. Quite a few revisions ended up available all through the many years on the injectors and gas pump, and I feel BMW has at last arrived at one thing resembling stable. 

The newest Index 12 gas injectors have mainly eliminated the troubles of the before versions, which started out at Index . Positive, there are exceptions that have someway lasted given that 2007. I would try to get the maximum out of no matter what is mounted on the auto due to the astronomical price tag of a new established of injectors. Brace your self. $3,514. 

It is straightforward enough to notify if the injectors are going terrible. If the vehicle runs inadequately on a cold get started with slight stutters or misfires, it’s likely that an injector is bad or that the automobile wants a carbon cleansing. Even now, this is quickly the most costly mend in terms of pieces price for most N54s. The extra probably failure is the large-strain gas pump, which normally gentle-fails with a lengthy crank trouble right before it just doesn’t begin at all. That will price $571 for a alternative section from the supplier that works as nicely as a genuine portion. It’s also a pretty easy work to swap it.

In truth, the rabbit gap of possessing this motor goes a lot further. But this should really primary any person wanting into possessing an N54-run BMW. Most of the main issues are coated below but hope to uncover modest difficulties and gremlins. Soon after all, it’s a decade-previous BMW motor. The remaining tally delivers me to my knees: $7,500ish. Which is if I chose to do upgraded turbos and change the gasoline injectors. Around 3-quarters of that can be saved if it’s just the VTT wastegate package and not getting new injectors. 

It’s been about four years considering the fact that I owned my 2007 BMW 335i. Firms like VTT experienced not still figured out a great deal of the alternatives we have now, but these new developments make me want a person all over again. With the mass tuner adoption of the latest BMWs, it appears to be like there is hope in proudly owning individuals devices, even if the price to make them vaguely resemble a dependable car is significant. Positive, loads of fashionable autos give what these previous Bimmers do on paper, but if tinkering is your detail, these center-aged birds present something great for not a ton of original dollars but are high-priced to modify. At the end of the journey, you do at least get a potent luxury coupe that drives wonderful and has a ridiculous stereo.

Correction: July 19, 2:00 PM ET: We termed the 335i “the initial turbo BMW” when in fact that honor belongs to the BMW 2002 Turbo. The N54-run 335i was, on the other hand the initially twin-turbo BMW. We regret the mistake.