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What You Need To Know About BMW Swirl Flaps and How To Solve The Problem With Them

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  • What You Need To Know About BMW Swirl Flaps and How To Solve The Problem With Them
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28.05.2024

Swirl flaps are a BMW system that has been introduced to help burn the fuel mixture in the cylinder better due to the fact that diesel engines do not have throttle valves and it is not possible to adjust the air-fuel ratio. A diesel engine without vortex valves operates between a poor and a rich fuel mixture, because the only way to regulate it is through fuel injection.

Design of the first generation swirl flaps that are made of made of metal.

Unfortunately, swirl flaps are responsible for countless damaged engines and costly repairs due to design errors or metal fatigue. Once damaged, the cylinder sucks them in and causes great damage.

This is how damaged valves damage the cylinder.

Typical swirl flaps  suction damage.

The vortex valves are positioned in the inlet and are controlled by vacuum (DDE 4.0) or electrically (DDE5.0 / DDE6.4) by the engine ECU.

Effects of malfunctioning valves:

  • Swirl valves are  stuck in open position: Deterioration of exhaust gas performance at lower speeds.
  • Swirl valves are stuck in closed position: Approximate power loss of 10% at high engine speeds.

How swirl flaps work:

Performance characteristics:

The vortex valves are in the closed position, at low engine speeds and small amounts of fuel injected (controlled by the ECU card).

They open under the following conditions:

  1. coolant temperature <14 ° C OR * fuel quantity> 24 mg OR
  2. engine speed 2250 rpm OR
  3. inlet air temperature <-5 ° C

BMW and Pierburg have decided to produce diesel engines with metal vortex valves. The speed at which the pistons in the diesel engine operate is at least 60 rpm, so a sucked vortex valve will break and cause a number of damages inside the engine.

In most cases, one or more pistons are severely damaged, as a bonus you get valves, in some cases a head or turbocharger. And this combination with a BMW engine is like a cumulative jackpot  🙂

In 2004, BMW began work on the problem and improved the design, however, a number of owners reported ongoing problems in this area.

The solution to this problem is by removing the vortex valves and plugging, which does not affect the performance of the engine and at the same time, you can safely pass the exhaust test.

Engines:

M47 (136hp VP44 fuel pump) has no valves.

M47N common rail engine (including M47N / M47TU / M47TUD20) (150hp. Face lift model from 2001 -) has valves.

M57 engines (M57D) (525d & 187hp. 330d) cars with manual transmission do not have valves, but those with automatic have.

M57N engines (M57TUD) (525d & 330d 204hp) have vortex valves.

Ruined swirl flaps:

The plugs that replace the vortex valves are easy to find on the internet, but you can also find them here on our website.

Typical plugs:
 

Disassembly of vortex valves:

The vortex valves can be safely dismantled and in most cases if they are  removed properly no loss of power is felt.

Final list of models for which vortex valves are installed:

Engine: M47N/M47TU/M47TUD20

Applications:

* 110 kW (148 hp) and 330 N·m (243 lb·ft)

o E46 320d 2001-2005

o E83 X3 2.0d (up to end of 2006)

Engine: M47TU2D20

The engine was updated again in 2004 as the M47TU2D20. Still at 1995 cc, it produced more power across the range.

Applications:

* 120 kW (161 hp) and 340 N·m (251 lb·ft)

E60/E61 520d

E87 120d

E90/E91 320d

E83 X3 2.0d (end of 2006 onwards)

Engine: M57/M57D25

M57D25 was introduced in 2000.

Applications:

* 166 PS (122 kW; 164 hp) at 4000 rpm, 350 N·m (260 lb·ft) at 2000-2500 rpm with a 4750 rpm redline, models:

2000-2003 E39 525d *Vehicles With Automatic Transmission ONLY*

Engine: M57N/M57TU/M57TUD25

M57TUD25 was introduced in 2004.

Applications:

* 177 PS (130 kW; 175 hp) at 4000 rpm, 400 N·m (300 lb·ft) at 2000-2750 rpm models:

E60/E61 525d

Engine: M57/M57D30

M57D30, also called M57D29, was introduced in 1998.

Applications:

* 184 PS (135 kW; 181 hp)@4000, 390 N·m (290 lb·ft)@1750-3200 models:

E39 530d *Vehicles With Automatic Transmission ONLY*

E46 330d/330xd *Vehicles With Automatic Transmission ONLY*

* 184 PS (135 kW; 181 hp)@4000, 410 N·m (300 lb·ft)@2000-3000 models:

E38 730d *Vehicles With Automatic Transmission ONLY*

E53 X5 3.0d

* 193 PS (142 kW; 190 hp)@4000, 410 N·m (300 lb·ft)@1750-3000 models:

E38 730d

E39 530d

Engine: M57N/M57TU/M57TUD30

M57TUD30 was introduced in 2002. It originally produced 160 kW (215 hp) at 4000 rpm and 500 N·m (370 lb·ft) at 2000-2750 rpm, but was tweaked for 150 kW (201 hp) at 4000 rpm and 410 N·m (300 lb·ft) at 1500-3250 rpm for 2003 and again for 200 kW (268 hp) at 4000 rpm and 560 N·m (410 lb·ft) at 2000-2250 rpm in 2004.

Applications:

* 204 PS (150 kW; 201 hp)@4000, 410 N·m (300 lb·ft)@1500-3250 models:

E46 330d/330Cd/330xd

E83 X3 3.0d

* 218 PS (160 kW; 215 hp)@4000, 500 N·m (370 lb·ft)@2000-2750 models:

E53 X5 3.0d

E60/E61 530d/530xd

E65 730d

* 272 PS (200 kW; 268 hp)@4000, 560 N·m (410 lb·ft)@2000-2250

E60/E61 535d

* 245 PS (180 kW; 242 hp)@4000, 500 N·m (370 lb·ft)@2000-2250

* 286 PS (210 kW; 282 hp)@4000, 580 N·m (430 lb·ft)@2000-2250

Engine: M57TU2D30

M57TU2D30 was introduced in 2007, making its debut in the facelifted E60 and E61.

* M57TU2D30-UL: 197 PS (145 kW; 194 hp)

* M57TU2D30-OL: 235 PS (173 kW; 232 hp)@4000, 500 N·m (370 lb·ft)@2000-2750

* M57TU2D30-TOP: 286 PS (210 kW; 282 hp), 580 N·m (430 lb·ft)

Applications:

* 197 PS (145 kW; 194 hp), 400 N·m (300 lb·ft) models:

E90/E91/E92 325d

E60/E61 525d/525xd

* 231 PS (170 kW; 228 hp)@4000, 500 N·m (370 lb·ft)@2000-2750 models:

E65 730d

E90/E91 325d

E90/E91 330d/330xd

* 235 PS (173 kW; 232 hp) models:

E60/E61, BMW E70, BMW E71

* 286 PS (210 kW; 282 hp), 580 N·m (430 lb·ft) models:

E60/E61 535d

E70 X5 3.0sd

E71 X6 xDrive35d

E83 X3 3.0sd

E90/E91 335d

The above models are listed for information only if you want to to make sure your engine has valves installed, please contact a competent person.

Please note that the information described above is for informational purposes only and does not claim to be reliable. Mr-key.com is not responsible for any repair work you undertake that is related to the topic described in this article.

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Car keys have changed dramatically in the last 20 years. What was once a simple mechanical tool has become an essential electronic device packed with functionality. From remote locking and trunk opening to push-start ignition systems and proximity sensors, today's car keys do a lot more than just turn in the ignition. However, this increased functionality also means more components that can fail—and when they do, the inconvenience can be frustrating or even immobilizing. For many drivers, key problems seem to come out of nowhere. A button stops working, the car doesn’t start, or a backup key won’t respond. Understanding the most common issues with modern car keys can help you avoid unnecessary trips to the dealership and identify quick fixes at home. Below, we’ll explore the ten most frequent car key problems, how to recognize the symptoms, and what steps to take to get your key working again—often without spending a fortune. 1. The Key Fob Has Stopped Responding One of the most common complaints drivers have is that their key fob simply stops responding. The remote may no longer lock or unlock the vehicle, the trunk button might stop working, or there may be no visible LED indicator when you press a button. In most cases, the culprit is a dead battery—something that’s inexpensive and easy to replace. Most key fobs use a CR2032 coin-cell battery, which can typically be changed with a small screwdriver or a plastic pry tool. If replacing the battery doesn’t bring the fob back to life, the issue may be with the internal electronics. Moisture, drops, and general wear over time can corrode or damage the tiny circuit board inside. In such cases, replacing the outer shell might not be enough—you may need to invest in a full replacement or transplant the electronics into a new case if only the buttons or housing are damaged. 2. 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In many cases, the outer shell has simply degraded, while the electronic board inside remains perfectly functional. The most effective fix is to replace the key shell. These replacement housings are inexpensive and widely available for most major vehicle brands. Simply open the fob, transfer the circuit board, battery, and buttons into the new shell, and your key will feel and function like new again—without any need for reprogramming. 6. Your Key Fob Got Wet Water and electronics rarely mix well, and key fobs are no exception. Whether your key was left out in the rain, fell into a puddle, or went through the washing machine, moisture can quickly short-circuit the internal components or lead to long-term corrosion. If your key gets wet, act fast. Remove the battery immediately and open the case to allow air circulation. Use desiccants such as silica gel packets to dry out the internal parts—avoid using rice, which is far less effective. If corrosion is visible, gently clean it with isopropyl alcohol and a cotton swab. If the key still doesn’t work after drying, the damage may be permanent and require replacement. 7. The Key Shell Is Cracked or Broken Keys endure daily use, pocket pressure, accidental drops, and exposure to the elements. Over time, the plastic casing of the fob can crack, split, or completely fall apart, leaving internal electronics vulnerable. Although a broken shell doesn’t necessarily mean the key is non-functional, it can make usage difficult and risky. Thankfully, key shell replacements are an easy and budget-friendly solution. You can often reuse all your original components, including the battery, buttons, and transponder chip. Replacing just the shell avoids costly reprogramming and restores your key’s durability and appearance. 8. The Key Still Doesn’t Work After Replacing the Battery Replacing a fob battery is supposed to solve the problem—but sometimes it doesn’t. If your remote remains unresponsive after a battery change, you may have installed the wrong type of battery, inserted it incorrectly, or failed to clean the contact points inside the fob. In some cases, the circuit board itself may be damaged or shorted out. Double-check that the battery type matches the original (commonly CR2032). Ensure it’s properly seated and that the metal contact tabs are clean and secure. If the problem continues, the issue likely lies with the circuit board, and the fob may need to be replaced entirely. 9. You’ve Lost Your Only Key Few things are more stressful than losing your only car key—especially if you don’t have a spare. Most modern vehicles require the key to be electronically paired with the car, so simply cutting a new blade isn’t enough. You’ll need your Vehicle Identification Number (VIN), proof of ownership, and a visit to either a dealership or a certified locksmith. Some aftermarket services can offer replacement keys that are compatible with your vehicle at a lower price than the dealership. Once the new key is cut and programmed, be sure to create and safely store a backup key to avoid being locked out in the future. 10. The Spare Key Doesn’t Work Anymore Spare keys are often kept in drawers or glove compartments for years without use. When finally needed, many drivers are surprised to find that the backup key doesn’t work. Batteries may have died, circuit boards may have degraded, or the key may have fallen out of sync with the vehicle. Start by replacing the battery. If that doesn’t work, the spare may need to be reprogrammed to the car. Keeping your spare key in a safe, climate-controlled environment and testing it occasionally is the best way to ensure it's ready when needed. Car key problems can range from mildly inconvenient to seriously disruptive—but the majority are entirely fixable, often at home and at minimal cost. Understanding the common causes behind these issues allows you to respond quickly, avoid dealership prices, and extend the life of your keys. At mr-key.com , you’ll find a wide selection of replacement key shells , batteries , blades , and complete electronic keys compatible with dozens of vehicle brands. With proper care and the right tools, you can keep your key in excellent condition and avoid ever being stranded due to a faulty fob.

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