BMW frequently uses the phrase “Valvetronic” in their press releases, however it is rarely explained to the general public. Without completely comprehending how it functions or what it eventually does for our automobiles and for us, we have all grown accustomed to it.
On their Youtube channel, the staff at Engineering Explained took the effort to explain the Valvetronic technology.
Here is a brief explanation of the Valvetronic technology and how it functions before we watch the video. A variable valve timing system called Valvetronic provides continuous and exact control over the duration and variable intake valve lift, which ranges from 0.3 to 9.7 mm (0.18 to 9.9 mm for Valvetronic II and III).
The independent Double VANOS system, which continuously alters the timing, is frequently used in conjunction with it. Instead of a butterfly valve in the intake tract, engines with valvetronic rely on the amount of valve lift for load control. In other words, when driving normally, the “gas pedal” controls the throttle plate rather than the Valvetronic hardware.
The intermediate arms (lift scaler), a second pair of rocker arms used in Valvetronic cylinder heads, are positioned between the valve stem and the camshaft. Through the use of an additional, electronically controlled camshaft, these intermediate arms are able to swivel around a central axis. The intake valves’ lift can be changed by this movement alone, without the aid of the intake camshaft, from fully open, or maximum power, to practically closed, or idle.
The Valvetronic system can only be briefly described in words, however the movie below goes into more detail and includes some graphics.
In This Article...
Valvetronic
The intake valve timing and duration can be infinitely adjusted using the BMW Valvetronic technology, which combines variable valve lift and variable valve timing. The method obviates the need for a throttle body when used frequently and promises to increase fuel economy and pollutants.
Valvetronic was first used by BMW in 2001 on the 316ti small and has subsequently been incorporated into many of the company’s engines. The N55 engine was the first turbocharged engine to use this technology.
Do BMW engines with Valvetronic require throttle bodies?
The claim made by BMW that the flow of intake air and, consequently, the engine load are regulated by the little amount of intake valve lift as opposed to the throttle opening is largely to blame for the uncertainty surrounding how the Valvetronic systems of BMW operate. This method is referred to by BMW as “throttle-free [engine] load control.”
Worse even, some observers assert that at low to moderate engine speeds and loads, Valvetronic devices eliminate the necessity for a throttle body. Alternately, some discussions contend that a Valvetronic-equipped BMW engine only requires a throttle body to control intake airflow during WOT conditions, and that the system serves the role of the throttle body at low to intermediate engine speeds and loads.
Do you understand these assertions? These comments do not make any sense to this writer, but let’s give it some thought since it is not my place to inform BMW’s design experts that they are mistaken. For instance, if one keeps in mind that the DME controls the idle speed and quality by opening the throttle plate to a range between around 3% and 4%, detecting Valvetronic faults can be made significantly simpler.
Therefore, a BMW engine cannot run at idling speed without a throttle body, despite the limited intake valve lift that results in a relatively high manifold vacuum pressure (low vacuum). It is unnecessary to complicate matters by claiming that intake airflow is a function of valve lift under minimum valve lift conditions as opposed to a function of throttle opening.
Practically speaking, the DME gathers information about the airflow entering the engine as recorded by the MAF sensor while a BMW engine is running at idle speed. However, keep in mind that the MAF sensor can only measure the airflow after it has gone through the throttle body. Due to the fact that a throttle plate is needed to control idling speed, it is difficult to comprehend how Valvetronic technology eliminates the requirement for a throttle body at low engine speeds.
We believe we have clarified some of the ambiguity surrounding throttle bodies on engines with Valvetronic, so let’s move on to the following query:
carve
In another post, someone brought up valvetronic’s increased efficiency. When I gave it some thought, I realized that it simply didn’t make sense. Maybe someone can correct me on this.
You MUST lower the volume of air entering the cylinders in order to run your gasoline SI engine at less than maximum torque at a specific rpm (without running extremely lean like diesels do). Most engines accomplish this by throttling down the pressure using a butterfly throttle valve. Through minute adjustments to valve lift, Valvetronic throttles the engine. To draw air in against this obstruction, the motor must exert just as much effort as to pull air in against a throttle valve. To have a pressure drop is the whole POINT of ANY throttle. The equivalent of opening the throttle wider than intended would occur if it were done any other manner and the pressure drop, and thus pumping losses, were decreased.
Therefore, it appears that valvetronic must inevitably result in the exact same pressure decrease as a throttle valve. This process is far more labor-intensive, intricate, unreliable, and expensive. It is rarely used by M engines, and the N53 got rid of it to make place for direct injection. What purpose does valvetronic serve?
What does BMW’s Valvetronic do?
Between the valve stem and the camshaft, a second set of rocker (intermediate) arms are used in valvetronic engines. An additional, electronically controlled camshaft allows these intermediate arms to revolve around a central axis. The intake valve lift can be changed from fully open to practically closed by this action alone, independent of any movement of the intake camshaft.
In theory, the system is incredibly effective. The problems start later in the life of the vehicle when components deteriorate from improper or delayed maintenance. The BMW N42 Eccentric shaft system is shown in the diagram below since it is by far the most straightforward. The latest BMW V8s use the same method.
Over time, the eccentric shaft and rockers deteriorate, resulting in either poor running or a misfire in the car. These rockers are so perfectly constructed that each one is given a unique number. A replacement shaft is then purchased from BMW using this number.
The main causes of valvetronic failure are frequently improper maintenance or aftermarket oil filters. The aftermarket oil filter on the right side has begun to crumble, as seen in the image above. This results in a decrease in oil pressure and has a significant impact on how quickly the valvetronic system wears down because it isn’t receiving enough oil to keep everything properly lubricated. We specifically utilize genuine BMW oil filters because of this.
Every time we service a Valvetronic engine, we replace the needle bearings (shown), eccentric camshaft, whole set of rockers, oil filter, and oil change with engine oil that is in accordance with the manufacturer’s specifications. Timing chains and intake camshafts may need to be replaced on engines with substantial damage.
These Valvetronic engines are repaired with specialized equipment. At Grosvenor, we make significant investments in tooling to guarantee that every repair we perform is flawless.
How is a BMW’s Valvetronic adjusted?
- Connect the plug in the first step. The plug for the BMW Valvetronic motor has two pins.
- Step 2: Turn on the ignition: Next, you must turn on the ignition and set it in the proper position.
- Step 3: Apply the gas pedal:
How is the BMW Valvetronic exhaust system designed?
You’ve probably heard of Valvetronic if you’re a fan, customer, or prospective customer of Armytrix. It is a key selling point of Armytrix exhaust systems and has forced the entire exhaust industry to adopt the same technology across the board. The Valvetronic system’s entire purpose is to provide you a choice over how loud you want your car to be. You probably don’t want your automobile to be very loud when you leave early for work because it will annoy your neighbors. You want to hear those great noises your automobile makes while you’re out on the open road or tearing up a canyon road.
By connecting a vacuum source from your engine to the control module, the Valvetronic system enables you to toggle between being quiet and being loud at the touch of a button using the remote control that comes with the car or through a smartphone app. When you click a button on a remote control or smartphone app, Bluetooth is used to connect you to the OBDII module. This OBDII module instructs the exhaust valve module whether to open or close the exhaust valve in response to engine vacuum. Additionally, the exhaust valve module has an automatic mode that allows you to specify the throttle position or RPM range to determine when the exhaust valve opens and closes.
With the Valvetronic system engaged, you can also increase power, especially if your car has a turbocharger, in addition to receiving a brutal sound. The exhaust gas will flow more freely when the valve is open because it won’t have to pass through a muffler, depending on the car, modifications, and tuning you have. Depending on whether you are operating an open or closed boost cycle, you may notice a modest rise in boost pressure in a turbocharged car, which will enhance horsepower.
My BMW Valvetronic has to be reset.
Connect the valvetronic motor’s 2 pin plug and insert it. The valvetronic motor will automatically reset to factory specifications after you turn the ignition to position 2 and depress the accelerator pedal 10 times in a span of 15 seconds.
Valvetronic actuator: what is it?
To help the vehicle achieve the highest potential performance and fuel efficiency, the Valvetronic actuator regulates an eccentric shaft that determines intake valve lift. Sadly, these motors are susceptible to failure with time, which can cause a loss of power and the appearance of the “check engine” light. We are able to provide this new actuator from VDO, a significant savings over what a BMW shop would charge.
After the actuator has been changed, the Valvetronic system’s “limit stops” frequently need to be re-calibrated using a unique BMW diagnostic tool. Before installation, we advise communicating with a qualified BMW mechanic.
This valvetronic actuator was ordered by me two days before Christmas, and it was delivered within a day. The solution, which resolved the issue resulting in a persistent engine light, is of original OEM quality.
Is driving possible without Valvetronic?
At exceptionally low lift settings, the automobile might not even idle. When the dme notices valvetronic isn’t functioning properly, it disables it with the valves at maximum lift, therefore you should have just unplugged it instead of attempting to actuate it via software. Even with valvetronic off, the vehicle still handles well.