What Is The Difference Between A BMW N51 And N52?

Bentley utilizes the same image for the N51 and N52. Every N51 has an automated tranny. The N51 and N52 are nearly impossible to distinguish from one another because of how similar they are. But

  • Cylinder Head Cover – The cylinder head cover on the N51 is made of plastic and features integrated crankcase ventilation, whereas the one on the N52 is constructed of magnesium.

Despite this distinction, these engines cannot be distinguished by just lifting the hood. The N51 and N52 are identical in appearance.

Examining the car emissions plate under the hood is the quickest way to figure out which engine you’re working with. The pertinent information can be found in the third row, on the left side of the plate. The N51 has a SULEV tag, but the N52 will be labeled as an LEV.

My E82 128i/E9X 328i: Regular LEV or SULEV?

Are you unclear if your E82/E90/E92 model from 2006–2011 qualifies as a SULEV model? You should be able to recognize a SULEV E82/E9X model using this page. First, some background information Super Ultra Low Emissions Vehicle is referred to as SULEV. The California Air Resources Board (CARB) established this guideline, and the federal government and other states have followed suit. Although almost all BMWs are LEVs (Low Emission Vehicles), the whole BMW model line is required by law to fulfill certain low emissions objectives. BMW has specific SULEV variants in order to increase their average while selling high-performance vehicles like the M5 and X5M. A certain number of automobiles, specifically in California, must be sold under SULEV spec or the manufacturer may be subject to severe fines. The BMW N51 engine package was created by BMW specifically to meet the SULEV specification. Your E82 128i, E90 328i, or E92 328i most likely came with the N51 SULEV engine if it was first acquired in California, Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Washington state, or Washington, D.C. It’s not a terrible thing to have the SULEV requirement, but if you have a N51 engine, you should be aware that several parts differ from those in regular N52 engines.

The N51 and N52 are identical in appearance. The valve covers of the M56 SULEV and M54 engines in the E46 had a distinct aesthetic distinction from one another. With the N51 and N52, it is not the case. The emissions label on the bottom of the hood makes identification the simplest.


From 2004 to 2015, the BMW N52 was a naturally aspirated straight-six petrol engine. The N52 made its début on the E90 3 Series and E63 6 Series, taking the place of the BMW M54.

The N52 was the first water-cooled engine with an engine block made of a composite of magnesium and aluminum. Additionally, in 2006 and 2007, it was named one of Ward’s 10 Best Engines.

The BMW N53 was introduced in 2007, and this caused the N52 to start being phased out in European markets. However, because of the high quantities of sulfur in the gasoline, the N53 was ruled inappropriate in markets like those in the United States, Canada, Australia, and Malaysia. The BMW N20 turbocharged four-cylinder engine started to replace the N52 in 2011 and continued doing so until the N52’s manufacture ceased in 2015.

Is there anything that can be quickly determined from a typical engine compartment photo to determine whether a car is a N51 or a N52? It would save me a ton of time as I’m now looking for a 128i online.

It’s fairly simple. Check the emissions label after lifting the hood. On the label, it will say LEV or SULEV.

I bought a sulev despite the fact that I live in a state where they are not legal. Not a big deal because it’s not nearly as bad as it was with the E46.

The air pump and line should be located just in front of the coolant tank. For N52s, that region is available. Inspect the front license plates as well. Front plates are required in most N51 states.

Is N52 preferable to N51?

N51 vs. N52 in BMW The N51 and N52 engines are nearly identical, making it difficult to distinguish the changes visually. Checking the emissions label on the underside of your car’s hood is the simplest way to determine what engine is in it. While the N52 will have “ULEV,” the N51 will say “SULEV.”

What model of BMW has a N52 engine?

One of the most popular and successful inline-6 engines made by BMW is the N52. The N52 was primarily used in the E90 325i, 328i, and 330i as well as the E60 525i and 528i models. It was also used in a number of other vehicles, such the 128i, X1, and Z4, to name a few. From 2004 until 2015, the N52 was manufactured before being superseded by the turbocharged N20 engine. The M54, which was utilized in a number of E36, E39, and E46 models, was replaced by this model.

BMW was able to refine several parts of the engine during the course of manufacture thanks to the lengthy production history. Even top 10 best engines awards were given to the engine in 2006 and 2007. The N52 still experiences a good number of typical dependability issues, though. We’re going to talk about the top 7 engine problems that the N52 has.

The N52 has proven to be more dependable than its larger sibling, the N54, thanks to the engine design. Drivers of the N52 won’t have to worry about these two typical N54 problems because the N52 lacks an HPFP or direct injection. You may read our tutorial on N54 engine issues to compare the two as well!

The 328i has N52, right?

The BMW N52 engine’s specifications for the E90 and E92 328i are as follows:

The 3.0L inline-6 N52 engine of the 328i is naturally aspirated. To assist keep weight off the front axle, it incorporates a block made of lightweight magnesium and aluminum. Additionally made of aluminum, the head has 24 DOHC valves. Electronic throttle control, double-VANOS, and valvetronic are features of the BMW N52 328i engines. Better performance and fuel efficiency are delivered thanks to all of this technology.

Can a BMW N52 be supercharged?

The freshly created Gen.3 E-Charger G1 based supercharger system for the BMW N52 engine family is something that ESS Tuning is happy to provide. This supercharger system is made to provide the customer with a 100% bolt-on installation that is very quick and simple. We increase the power output by 80 to 100 horsepower with this supercharged kit!

The tiny, noise-free, and extremely effective self-lubricating E-Charger G1 supercharger unit, operating at 6-6.5PSI boost, is a component of the ESS Tuning G1 supercharger system. There is no worry of having to run additional oil lines to and from the engine with a totally sealed supercharger system. The G1 supercharger is also a lot quieter than earlier ones included in this kit.

The supercharger system consists of the ESS E-Flash OBD2 cable and unique ESS engine software that is fully tuned for the G1 supercharged engine. It delivers completely optimized fuel supply, recalibrated VANOS management, and the best ignition timing under all circumstances. Additionally removed are the highest speed governor and dyno limiter. The E-Flash provides a full diagnostic and code clearing capability and enables the end user to upload the supercharged ECU software from any PC running Windows XP or newer. Any ESS software updates in the future can be downloaded right to the vehicle and delivered via email. It will be possible to preserve and later quickly restore the original ECU software.

Up until you require power, the car performs as it normally would and provides outstanding acceleration. Power buildup is 100% seamless.

The N52/N52N G1 Gen.3 kits, like all ESS supercharger systems, are tested and tuned for more than 50,000 street and track miles on a variety of vehicles around the world, 60+ hours on a load dyno, full load top speed endurance testing on the German Autobahn, and final certification laps on the Nurburgring. All OBD-II functions are maintained by the system, which is supported by a thorough 2-year, unlimited mileage warranty program. This entire system comes with everything you need and is completely bolt on. Using standard hand tools, installation takes 4-6 hours; there are no permanent changes to the vehicle required.

With the N52/N52N B30 engine, both manual and automatic variants are compatible with the N52 G1 supercharger system, a non-intercooled system that operates at 6.0–6.5 PSI. Requires 93AKI/98RON or higher.

*The 3-stage DISA manifold from the 330/530, among other models, works wonderfully with this kit, and we have created software to seamlessly incorporate this feature on vehicles that weren’t built with this manifold at the factory. Run headers on the N52 engine at all costs; doing so causes a severe O2 feedback timing problem and improper AFR regulation. When coupled with boost, this could result in catastrophic failure! Any problems with a N52 fitted with aftermarket headers will not be supported by ESS Tuning.

Drivetrain loss is corrected by 15% above RWHP as measured by a dynograph (RWHP/0.85).

How reliable is the N52 engine?

The N52 was a superb successor to its predecessor, the M54, with toughness and lightness as its strong suits. Due to their small weight, which improved weight distribution, these engines were capable of producing up to 260 horsepower when equipped with double electronic variable valve timing. Add a variable-length intake manifold, and your engine will be producing a sound that is comparable to the renown 2JZ “GE.”

The 2JZ GE had forged internals like conrods and pistons (the GTE had different pistons and head gaskets), whereas the N52 was hesitant to implement any significant forced induction, despite a few pricey supercharger kits that at most extract an additional 50 horsepower.

There is always the possibility to forge the entire unit, of course, if you have the money, but why would you want to do that when you can get a N54, the GTE’s envious rival? The N52 is essentially similar to a meal that is best enjoyed on its own. Null meat. Zero salad. Definitely no gravy, either.

The N52 is among the best sounding inline six engines thanks to its burbles, pops, and bangs, as well as its linear power range. Additionally, it has a special trick that allows it to travel down the highway and return 39 mpg. This may not sound like much, but keep in mind that this engine is also used in the e92 coupe, which can accelerate from a standstill to 60 mph in just six seconds. Not much room for compromise, then.

Is the N51 a reliable motor?

Hey everyone, as I’m waiting for my car to arrive from Germany, I thought I’d ask others who have the identical N51 engine a question. Any problems with it in terms of power or dependability?

The inline six has been refined by BMW. The N51/52/54 engines are unquestionably the silkiest, smoothest ones available. Sincerely, I was unable to distinguish between N51 and N52. People who complain that this car is slow are generally inexperienced drivers who have never driven one over 100 mph. Power is amazing.

The dependability problems are probably less related to the engine and more related to other things. For instance, a seat belt presenter or an iDrive that locks up

I was mainly thinking about problems with the SULEV engine specifically. I am aware of every other “problem”!

Yes, he had a topic about it in the past, however the majority of the threads are from early 2007 and are not up to date. I see, then!

That’s why I said “a while back,” you see. Even though it’s a little dated, the topic is still useful, so if you haven’t seen it, you should look it up and have a look. I only meant that. That wasn’t intended to be a form of snip

We haven’t experienced any problems with the n51. The majority of these engines are in good shape, and many individuals actually experience more problems than those who drive their cars the way they should be driven if they don’t drive them frequently and hard.

Thank you for the details. The information in Steve’s thread on what set the N51 apart was incredibly helpful. I’m relieved to hear that the SULEV engine is working properly for everyone.