It’s likely that you will come across the word “DISA Valve” at some point in the life of your BMW if it was manufactured in 2007 or before. The BMW Differentiated Intake System, often known as DISA (from the German “DIfferenzierte Sauganlage,” which translates to “Differenzierte Air Intake”), optimizes the engine’s operation under both partial and full load by modifying the intake manifold runner length.
The DISA valve regulates the variable length intake manifold to provide improved torque at low revs by closing and maintaining the intake runner long. It is positioned in the inlet plenum chamber. It opens up and shortens the intake runners at higher engine RPM to produce additional horsepower. A rough idle, decreased performance, and occasionally a rattling noise or Check Engine light can all result from it failing. If the engine has more than 60–80K miles on it, exhibits symptoms of rough running, or performs poorly, suspect the DISA.
In This Article...
What serves as a DISA valve?
The DISA valve regulates how air enters the engine and travels through the intake system. To shorten or extend the distance the air must travel to reach the cylinder chamber, the valve uses a flap that opens and closes.
The valve closes at low RPMs, forcing the air to travel the longer route to the cylinders. The valve opens up at high RPMs, shortening the route. As a result of the shorter path, there is less room for air. More compressed air, which is also more flammable, is the ultimate outcome.
Optimizing performance and fuel efficiency at both low and high RPMs is the DISA valve’s main objective.
The Fine Art of Perfect Timing: Intake Tuning
Your intake manifold is where air passes through before entering the engine. The air is finally distributed by this unassuming box to every cylinder, which then inhales it during the intake stroke. The problem is this.
The air that is being shut off by the intake valve when it closes after drawing in a fair amount bounces back towards the plenum. It moves to the very back of the plenum, bounces off once more, and proceeds directly in the direction of the identical intake valve.
The timing of the valves so that they open up just when that bouncing air comes right back is one of the fundamental concepts of effective engine performance. That wouldn’t be a problem in an engine with set RPM. However, a dilemma arises when working with a motor that must be effective at both low and high RPMs.
The main purpose of a DISA valve is to increase or decrease the plenum’s capacity. The valve is shut when your engine is operating at lower RPMs. This implies that the backflow of extra air that entered a closing valve may now require more time. The DISA valve opens and reduces the amount of time it takes for air to bounce back when the RPMs are high and the intake valve opens significantly more frequently.
Fortunately, the ECU handles figuring out how much the DISA valve needs to be opened.
Valve DISA
The DISA valve, which is found in the intake manifold, controls the pressure in the intake manifold to increase power and torque, however the hinge is prone to breaking. From Febi Bilstein, this replacement part is of the highest caliber.
Please be aware that the fitting information for this part is extremely specific. Please enter your vehicle information in our Quick Finder before placing your order.
The DISA valve, sometimes referred to as the air adjustment unit, regulates the flow of air through the plenum and the pressure in the intake manifold to increase torque in tighter spaces and power at higher revs. These, sadly, are a weak spot and frequently break, causing the flap to become caught and perhaps allowing debris to enter the motor unfiltered. Replacement, which should be done as part of appropriate preventative maintenance, is a relatively straightforward process and is located near to the intake manifold. Compared to a BMW Genuine replacement, these replacement DISA valve units are of great quality and considerably less expensive.
The DISA valve, a frequent but sometimes disregarded source of subpar performance at low RPM, is simply diagnosed by unplugging the device while the engine is running. Click here to read about how this DISA valve was installed on our very own E46.
Purchased this new DISA because my old one was beginning to rattle a lot and needed to be replaced. cheaper than purchasing from BMW, with the same or even higher quality. was easy to replace and arrived really soon. Torx bolts can peel, so use caution while using them.
Has the 328i got a DISA valve?
The DISA valve for the M52TU engine is this one, and it can be found in the intake manifold of the E46 323i/325i/328i, 1999-2000 E39 528i, and Z3 2.3/2.8. DISA, also referred to as variable length intake runners, stands for differential intake air control. Depending on the load and RPM, a flap mechanism directs the intake air into the manifold. The flap closes at low RPM, enhancing low and midrange torque. The most air volume is available for high RPM power when the flap is fully open at high RPM. The engine will seem sluggish or unresponsive in the low-mid RPM range if the DISA valve is broken. The DISA valve itself doesn’t have a trouble code, but a number of associated problems and check engine lights can be linked to it, including fuel trim, misfires, lean conditions, and fuel mixing. As the DISA solenoid tries to open the butterfly flap, there can also be a clicking sound coming from the driver’s side of the engine bay. Vacuum leaks can also be caused by the failure of the o-ring seal that surrounds the valve body.
It has a two-year warranty and is a brand-new Genuine BMW DISA valve for the E46, E39, and Z3.
Driving without a DISA valve is possible.
Although you can still operate without it, I advise that you do so as soon as you can. 1. Losing a little drivability is acceptable if the disa is absent.
Do the N51’s DISA valves exist?
This is the upper DISA valve of the N51 engine found in the SULEV E82 128i and E9X 328i, the N52 engine found in the E90 330i, E83 X3 3.0si, and E86 Z4 3.0si, as well as the N51 engine. DISA, also referred to as variable length intake runners, stands for differential intake air control. Depending on the load and RPM, a flap mechanism directs the intake air into the manifold. Upper and lower DISA valves are present on the N52O. Under the intake runners, this component, which is the upper valve, operates at high RPM. The upper flap closes at low and mid RPM, enhancing low and midrange torque. The most air volume is available for high RPM power when the flap is fully open at high RPM. In the upper RPM range, a broken upper DISA valve will make the engine feel sluggish or unresponsive. The DISA valve itself doesn’t have a trouble code, but a number of associated problems and check engine lights can be linked to it, including fuel trim, misfires, lean conditions, and fuel mixing. As the DISA solenoid tries to open the butterfly flap, there can also be a clicking sound coming from the driver’s side of the engine bay. Vacuum leaks can also be caused by the failure of the o-ring seal that surrounds the valve body.
It has a two-year warranty and is a brand-new Genuine BMW DISA valve for the E82, E90, E92, X3, and Z4.
N52 has a Disa valve, right?
330 is known as a three-stage manifold. Two valves are closed in the first stage, one opens in the second, and both open in the third.
The 3 stage DISA is exclusive to the OL N52, which is found in the 330i. The DISA is absent from standard N52 (from 328, 325).
What is the DISA’s purpose?
Through IT and communications assistance, the Defense Information Systems Agency (DISA), a combat support organization for the US government, links the US military and government.
The agency was established in 1960 and was first known as the defense communications industry (DCA), in part as a reaction to communication problems during World War II. By providing services like computer hosting, information assurance, international information exchange, and data services, the DISA currently assists American military all around the world in gaining access to vital information. The complete range of armed force activities, including offensive tactics, defensive tactics, counterterrorism and humanitarian initiatives, use DISA’s information systems.
The ultimate objective of the DISA is to achieve information domination by offering a business infrastructure that is so powerful that it gives the user a competitive edge.
How can I tell if my Disa valve needs repair?
- low fuel efficiency
- engine noise that sounds rattling
- power loss at high and middle RPMs
- inadequate low-end torque
- SES/CEL light and running lean codes
The loud rattling sound emanating from the intake system is the most obvious indicator of a broken valve. Air can leak past the valve in both the open and closed positions when the seals on the valve deteriorate, creating a loud rattling. You will also start to notice poor performance, a lack of power, etc. at this time.
The metal pin that secures the plastic valve in place is composed of metal. Plastic or the metal rod may get sucked into the engine if the valve or pin breaks, completely wrecking the entire engine.
which N52-powered BMWs are there?
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!
Can choppy idle be caused by a defective Disa valve?
A rough idle wouldn’t result from a DISA failure. In actuality, you could remove the butterfly and the automobile would still function. You should be fine as long as the electronics are connected in. The IDLE REGULATING VALVE is most likely to blame for the choppy idle.
What distinguishes a BMW N51 from a N52?
In areas of the United States with SULEV laws, the N51 engine, a SULEV variant of the N52, was offered for sale. A three-stage variable-length intake manifold (“DISA”) has been added in place of the one found on the N52 models, and the compression ratio has been decreased from 10.7:1 to 10.0:1.