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.” Examining the radiator is another technique to determine the difference. The EAC (Environmental Air Catalyst) Sensor for the N51’s unit was mounted to the radiator fins. This tiny instrument keeps an eye on the radiator’s operation.
The two engines are mechanically different in a few ways. The N51 had a decreased compression ratio of 10.7:1 to 10.0:1, a three-stage variable-length intake manifold in place of a single stage, and other changes. Additionally, the cylinder heads of the two engines vary because BMW modified the combustion chamber. The ventilation systems for the crankcase and the cylinder head cover are also different.
It’s important to note that BMW tweaked both engine variants to deliver comparable output numbers.
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How can I tell what type of engine my BMW has?
It has actually gotten harder to tell what’s inside the hood now that many SULEV cars have the N51 and others bear the N52. It was simpler to identify the engines on earlier models that used the M54 and M56 SULEV. There were important visual cues, especially on the valve covers. On the other hand, the N51 SULEV vehicles and N52 engines have extremely similar appearances.
If you want to be sure, you can check the label mentioned above beneath the hood. If it says SULEV, then the engine is the N51; if it says LEV, then the engine is the N52. There are further methods, such as checking your BMW car identification number. The engine type and attributes are indicated by the numbers 4 through 8 in this lengthy number. The VIN can be found in numerous locations under the hood as well as on the driver’s side of the dashboard, which can be accessed through the windshield.
Hopefully, the SULEV requirements will enable your BMW to contribute to the solution rather than the issue of the environment. To determine whether you are a low emission vehicle or a super-low emission vehicle, look at the label beneath the hood.
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There would be a badge on the left side of the trunk if it was xDrive. Since you live in California, the likelihood that you own a SULEV is 99.999997%. Instead of the N20, the SULEV motor is the N26. The variations are hardly noticeable. Since the N20 is not CARB compliant, it would be extremely strange to purchase a N20 motor in California.
BMW SULEV: What Is It?
SULEV stands for Super Ultra-low Emission Vehicle. BMW and other automakers were compelled to create a technology that causes their motorized vehicles to emit fewer emissions. The advancement of this technology was influenced by this.
SULEV is another designation given to vehicles that can emit 90% fewer emissions than typical gasoline-powered cars. Of the world’s top automakers, BMW was the first to produce this kind of technology.
Not all of BMW’s vehicles are SULEV models. LEVs, or low emission vehicles, make up the majority of their fleet. The law’s low emission targets can be met by the complete BMW model lineup.
A car equipped with SULEV technology performs unaffectedly. This technique focuses on various volatile vapor emissions, such as car warranties, and the evaporative system of the fuel tank. It doesn’t execute any actions that affect engine performance.
How can I tell whether my BMW is a SULEV? Looking under the hood of your BMW can reveal whether it is a SULEV vehicle. A SULEV engine will have “SULEV” engraved into the engine block somewhere. This word is a BMW N51 engine, if you see it. Your engine is a BMW N52, but, if you see the word “LEV” in its place. You can determine whether your BMW is a SULEV or an LEV by looking up its VIN (vehicle identification number).
I recently bought a 2012 335is. Although I had heard that BMW didn’t create a 335is SULEV, the carfax indicated that the vehicle was a SULEV, so I assumed that they had erroneously interpreted the “s” in the vehicle’s make.
Do all 335is models carry this classification, or did I accidentally end up with a SULEV 335is?
Due to more stringent emissions regulations, SULEV vehicles are mostly found in CARB states. Only a few things have changed, like bigger cats, a new radiator, a new crankcase breather system, etc. Performance is essentially the same. And the only N51 328i that was SULEV.
I initially believed that the compression ratio was the main distinction between the SULEV 328i (N51) and ULEV 328i (N52). 10:1 vs 10.7:1. So I placed the ULEV order. Later on, I discovered that the N51’s three-step intake manifold differs from the N52’s single stage intake manifold, likely to account for the lower compression ratio.
Which versions of BMW are SULEVs?
There are presently 5 vehicles that are virtually guaranteed to have a BMW SULEV engine, according to the most recent page on Wikipedia. These include the 128i, 328i, 325i, 325Ci, and 325iT models from the BMW 1 Series and BMW 3 Series, respectively. You can always perform a quick check by opening the hood and looking at the information sticker there if you possess one of these models or any other.
The sticker should read “Vehicle Emission Control Information” and include the header “Bayerische Motoren Werke AG” (BMW, in case you didn’t know). You can see which laws, including EPA and state laws, it complies with in this statement.
If your BMW is an LEV, you’ll see something like “California: LEV II PC” underneath “Conforms to regulations” on the second row. Your car thus satisfies the requirements for low-emission vehicles. You meet this requirement if you see “California: SULEV.” It will also show whether the BMW SULEV cars you own meet the aforementioned PZEV standards.
You can consider where and when you bought the car. Your BMW almost surely comes with the N51 SULEV classification if it was purchased in California, Connecticut, Maine, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Washington, the District of Columbia, Maryland, or Massachusetts.
The strongest classification system created to categorize zero-emission vehicles, such as all-electric automobiles, which have no emissions, is ZEV, which you won’t see on that label.
What does SULEV on a BMW mean?
A U.S. categorization for passenger car emissions is super ultra-low emissions vehicle (SULEV). In order to qualify, a vehicle must emit 90% fewer emissions than the typical gasoline-powered car. The SULEV standard is more stringent than the standards for LEVs and ULEVs, but it is not as harsh as the PZEVs (partial zero-emissions vehicles), which satisfy the SULEV level for tailpipe emissions but have zero evaporative emissions rather than reduced ones. Japan additionally classifies vehicles as SU-LEVs if they exhibit a 75% reduction in emissions compared to the 2005 emissions criteria. [More information required]
Is every BMW a SULEV?
In cars sold in states where SULEV was the standard, the newly revised M56 powerplant was mounted. However, the M56 began to clearly display signs of frailty over time.
The additional emission standards requirements made it more difficult than the M54, but the M56 had many of the same problems. The sole distinction is that fixing those problems on the SULEV versions cost more money.
The valve cover is a fantastic illustration of this. BMW went ahead and replaced the composite valve cover with an aluminum one to comply with the SULEV standards. The M54 is notorious to twist the valve cover, which results in oil leaks. Because it is constructed of metal, the aluminum one doesn’t leak.
However, the cover’s built-in crankcase ventilation valve had a weakness of its own. The real kicker is that BMW wouldn’t allow you just replace the damaged valve. This component has a part number, but you cannot order it. Instead, a brand-new valve cover is required.
Along with the injectors, the fuel rail underwent changes as well. If any of the injectors start to malfunction, you’ll need to look for rather unusual components (read: more expensive) because BMW employed a completely different arrangement on the M56.
In general, if you plan to purchase a 325i or 330iE463-series car, confirm that it is not a SULEV version. BMW only offered these in California, Massachusetts, New York, and Vermont, but since their owners moved, you can occasionally encounter SULEV variants in other states.
How can I tell what model of BMW I own?
Although your vehicle’s model number is prominently badged on the back of your BMW, internal classifications into E/F and G model codes also exist. The body style, model, and approximate age can typically be determined by specialists or dealers using this three-digit combination.
You can find the model code for your BMW E, F, or G using this short list. The car will always be referred to on our website (in any article or explanation) using the main body code.
What is protected by the BMW SULEV warranty?
If any emission-related component on your car is broken, BMWNA will fix it or replace it. This is the DEFECTS WARRANTY for your emission control system. This is, in my opinion, a two-part warranty, one of which covers the specific components listed in the SULEV parts list and the other of which covers a failed emissions test.
How long is the warranty on the BMW SULEV?
The good news is that when BMW sold that 128i SULEV in California, it was guaranteed to continue meeting emissions rules “for the life of the automobile,” not only when it was first manufactured. A long variety of emissions-related components are covered by a fifteen-year, 150,000-mile warranty.
Which motor powers my BMW 328i?
A 3.0-liter inline six-cylinder engine with 230 horsepower and either a six-speed automatic or manual transmission are standard on BMW 328i coupes and convertibles.
My BMW has a N51 or N52?
From 2006 to 2015, the engines were put into a wide range of various BMW automobiles. They can be found in the Z and X series, as well as the 1, 3, and 5 Series. Being aware of the type of displacement you’re dealing with is one simple technique to identify which engine you don’t have. N51 was only offered as a 3-liter engine, hence any inline-six of this generation that is 2.5 liters will be N52.
Following that, the following are some of the key variations between the two engines:
- Both the N52 and the N51 use aluminum cylinder heads, but the N51’s is unique due to changes made to the combustion chamber to comply with SULEV regulations. They cannot be switched out.
- Cylinder Head Cover: The cylinder head cover on the N51 is made of plastic and has integrated crankcase ventilation; the one on the N52 is made of magnesium.
- External crankcase vent valve with cyclone separator is a part of the N52’s crankcase ventilation system. The N51 contains an integrated vent valve, a labyrinth, and cyclone oil separation, as was already noted.
- On more powerful variants of the N52, the intake manifold is made of plastic and has a 3-stage DISA valve. The 3-stage DISA unit on N51 is utilized to account for various compressions.
- Piston/compression Ratio: For N52, this ratio is 10.7:1, but for N51, it is 10:1.
- The N51 utilizes a digital hot film meter, whereas the N52 features an analog version.
The problem is that despite all of these distinctions, it’s impossible to tell these engines apart by just opening the hood. Not like the M56 and M54 generations, for example. You could immediately distinguish the M56 SULEV from the M54 thanks to aesthetic differences.
But there is a solution. 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.