Problems with the intake flaps: symptoms, cost and affected models
We have documented 9 faults with the intake flaps in 9 engines, affecting 74 models of car in our database. The most important by severity and frequency: intake swirl flap breakage (swirl flaps) (BMW M47), broken intake manifold swirl flaps (BMW N47) and broken intake swirl flaps (BMW M57). At an independent garage, the repair costs from €600 to €1,200 depending on the engine or car.[1]
How it works and why it fails
Intake flaps (swirl flaps)
The swirl flaps in the intake manifold create turbulence in the air at low revs to improve combustion. On some diesels, their spindles or screws wear out and a flap can come loose inside the engine.
What to do
If your engine has a known history of breakages, ask the workshop about inspecting or replacing the manifold. An actuator fault usually triggers the engine warning light; a loose flap, on the other hand, can wreck the engine without any prior warning.
General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.
Common symptoms
The symptoms that come up most often in the documented faults with the intake flaps. Open each one to see what other faults cause it.
Problems with the intake flaps by engine
From most to least important (severity × frequency). Each page details the affected versions and years, symptoms, cost and how to check for it.
- 1Critical severityFrequency: Very frequentBMW M47Intake swirl flap breakage (swirl flaps)Yes: the common rail versions of the M47 (built since 2001) have flaps in the intake manifold that, with diesel soot and heat cycles, can break and be sucked into the cylinder, with a risk of serious damage to the piston, cylinder head and valves.
- 2Critical severityFrequency: CommonBMW N47Broken intake manifold swirl flapsYes: the N47's intake manifold has plastic swirl flaps that, with diesel soot and the passing years, can crack, come loose and be sucked into the cylinder, with a risk of seriously damaging the piston, cylinder head and valves.
- 3Critical severityFrequency: CommonBMW M57Broken intake swirl flapsYes: most automatic M57 and M57TU engines (330d, 530d, 535d, 730d, X3 3.0d and so on) have six metal flaps in the intake manifold that can seize, come loose and wreck a cylinder. The E53 X5 3.0d and the manual gearboxes of the first 330d/530d are free of them, according to a specialist workshop.
- 4Critical severityFrequency: CommonOM642Broken swirl flaps in the intake manifoldYes: the plastic rods of the intake manifold's swirl flaps become brittle and can break at around 100,000-200,000 km. If a loose flap is sucked into a cylinder, it can hit the piston and destroy the engine; this is why removing them preventively is recommended.Repair (garage): €600–€1,200Appears at around 100,000 km
- 5High severityFrequency: Common1.9 JTD/Multijet and 2.4 JTDIntake manifold flap failure (swirl effect)Yes: the intake manifold has flaps that create a swirl in the air at low revs, and their mechanism can seize or break with use. Two independent data sheets point to this fault as typical of Opel's 1.9 CDTI, with loss of power and the engine warning light on.
- 6Medium severityFrequency: Occasional2.4 JTD / JTDm MultijetIntake manifold flap failure (swirl flaps)According to Auto Świat, the intake manifold flaps of the 200 hp 2.4 JTDm often failed and left the car without power or in limp mode. In 2007 Fiat launched a corrective action that replaced the manifold, injectors and EGR; the 210 hp reportedly does not suffer from it, although Diariomotor disagrees.
- 7Medium severityFrequency: OccasionalHyundai-Kia eléctrico (Ioniq, Kona, e-Niro, Soul EV)Charging faults: interruptions, rejection at the charger and a locked charging flapAmong owner reports for the electric Kona, e-Niro and Ioniq, there are charging interruptions, rejection at some public points and a charging flap lock that gets stuck. These are minority cases, often resolved under warranty.
- 8Medium severityFrequency: Occasional3.0 TDI V6Worn intake flaps (swirl) and intake manifoldOn V6 TDI engines from 2004 to 2010 the control of the intake (swirl) flaps can develop play and turn on the engine warning light with code P3134. Hella says the flap and actuator form one unit and are replaced together; on the Q7 4L it is the category owners cite most.
- 9Medium severityFrequency: RareD4/D5Breakage of the intake manifold swirl flap (5-cylinder)One documented case in the first-generation Volvo XC60 (2.4d of 163 hp) describes replacement of the intake manifold swirl flap at 120,000 km. With the sources available we have only been able to confirm that specific case for this engine, so we cannot say it is widespread.
Engines with faults with the intake flaps
Intake flaps: compare prices in shops
Search for the part using the make, model and engine of your car: in the shop, the registration plate or VIN filters the parts that fit.
Inlet manifold
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Problems with the intake flaps by make
Problems with the intake flaps in your car
7 cars have several documented faults with the intake flaps. Choose yours to see only the ones that affect them, by engine and by year.
How much it costs to repair a fault with the intake flaps
Sorted from the most expensive repair to the cheapest. Prices in Spain including VAT (parts and labour); what each figure includes is on its page.
- Broken swirl flaps in the intake manifold
OM642Critical severity
- Garage
- €600–€1,200
- Dealer
- No data
- Published figure[1]
How we calculate costs · The most expensive repairs across all engines
OBD fault codes with the intake flaps
The codes the ECU usually stores when this part fails: what they mean, causes and what to check.
Frequently asked questions
Which engines have the most faults with the intake flaps?
By severity and frequency, the BMW M47 (intake swirl flap breakage (swirl flaps), critical severity), the BMW N47 (broken intake manifold swirl flaps, critical severity), the BMW M57 (broken intake swirl flaps, critical severity), the OM642 (broken swirl flaps in the intake manifold, critical severity), the 1.9 JTD/Multijet and 2.4 JTD (intake manifold flap failure (swirl effect), high severity) and the 2.4 JTD / JTDm Multijet (intake manifold flap failure (swirl flaps), medium severity). In total we have documented 9 engines with faults with the intake flaps.
How much does it cost to repair a fault with the intake flaps?
It depends a lot on the engine or car. At an independent garage, from €600 to €1,200, including VAT, based on the 1 fault with a documented cost. The most expensive is broken swirl flaps in the intake manifold (OM642).
What symptoms does a fault with the intake flaps cause?
The most frequently cited in the documented faults: engine fault warning light (check engine), gradual loss of power, sudden loss of power (limp mode), abnormal vibrations or unstable idle, deep metallic engine knock and bluish smoke from the exhaust.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- Mercedes OM642 : fiabilité, pannes fréquentes et coûts d'entretienAutoCopilot · Motoring press · published 2026 · consulted 26 September 2026 · in French