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1.9 CDTi Swirl Flaps - What, Where, Why and How Much?
The number of inquiries regarding the swirl flaps on the 1.9 CDTi 16V engines (engine codes Z19DTH and Z19DTJ) seem to be on the increase. This post aims to answer most of the commonly asked questions about these parts.
What are swirl flaps?
- The swirl flaps are small, square pieces of metal that are mounted in several ports of the intake manifold. There are two possible positions for these to be in - across the port, which blocks the flow of air into the engine - or inline with the port which allows air to flow into the engine.
- There are two ports for each cylinder on the 1.9 CDTi through which air can flow into the engine. One introduces a 'swirl' motion to the air as it enters the cylinder. This swirl ensures the fuel burns more evenly and thoroughly, reducing emissions and producing more power. The other port is a more direct path into the cylinder, which allows maximum air flow for greater power at high revs and a more freely revving engine.
(Diagram from Pierburg service bulletin SI0093)
- At low revs, the 'direct' port must be closed or blocked by the flap, otherwise all of the fuel injected into the cylinder will not be burnt, meaning increased smoke and soot from the exhaust. This is because the incoming air has insufficient 'swirl', as the air takes the easier path into the engine through the 'direct' port that should be blocked off.
- At high revs, both ports are open to allow the maximum amount of air into the cylinder. If the swirl flap remains closed, the air charge in the cylinder is reduced, causing more black smoke and reduced performance.
- A motor is mounted underneath the manifold that operates the swirl flaps - it moves the flap on no.3 cylinder directly, a rod on top of the manifold transfers this motion to the other cylinders.
Why do the swirl flaps fail?
- Due to the EGR valve that is fitted to the majority of modern diesel engines, a proportion of exhaust gas is recycled back through the engine to reduce emissions. This means the soot that is present in the exhaust gas coats all of the components in the intake manifold. This soot mixes with oil mist that is also found in the intake system, and forms a tar like substance.
- The build-up of tar and soot causes the flaps to stick. The bearings the flaps run in also wear due to uneven loading. Eventually, the excess load on the operating rod and ball joints cause them to become oval shaped and loose, leading to the operating rod coming adrift.
- Due to the wear in the bearings, pressurised air from the manifold can escape, along with soot and oil mist, leading to reduced performance and also an oily mess on the manifold.
I've found the operating rod adrift from the swirl flaps - what now?
- You can refit the rod to the swirl flaps, but if it has got to the stage where it is falling off by itself, due to vibration from the engine, it will not stay on for long.
- A temporary repair can be made by sticking rubber washers onto the underside of the cups on the operating rod. The hole in the middle of the washers are sized so they are a push-fit over the ball-joints on the swirl flaps. This makes the operating rod a much more secure fit, but still allows free movement. See this thread for one possible fix.
- In the long term, the only permanent fix is to replace the complete intake manifold assembly. The manufacturer of the manifold (Pierburg) has made modification to the bearings in which the swirl flaps move - this should result in increased lifespan of the manifold, and prevent future recurrence of the problem. Time will tell!
How do I know if I have a 'modified' inlet manifold?
- Somewhere on the manifold, should be a bar-coded sticker which shows the manufacturers part number of the manifold.
The original part number is 7.0186.00.0 or 7.00373.1.0.0
The modified part number is 7.00373.12.0
What are other symptoms of failed swirl flaps?
Engine management light may be on, and the following codes may be stored:-
P1109 - Swirl Actuator Malfunction
Cause:- Stiff/sticking swirl flaps overloading or stalling the drive module motor.
P2279 - Intake system air leak detected
Cause:- Charge air pressure in manifold leaking through worn swirl flap bearings.
There may be other symptoms whilst driving, such as lumpy running, hesitation and poor fuel economy, and an oily fume smell inside the car whilst the engine is running.
What's it going to cost to fix?
Vauxhall Part numbers and prices.
Below is the list of parts required under the TSB (technical service bulletin) and current retail prices (+ VAT).
1 x Manifold - 55210201 £197
1 x Manifold Gasket - 93179058 £12.90
1 x EGR gasket - 93181665 £2.80
1 x Throttle body gasket - 55205453 £2.01
1 x Swirl actuator - 55205127 £159
1 x Sealer/Locking compound - 90542117 £9.55
1 x Actuator arm - 93186274 £6.50
1 x HP fuel pipe - 55215517 £30.75
1 x HP pump pulley nut - 93178824 £2.63
1 x HP pump pulley washer - 93178879 £0.12
12 x Manifold nuts - 93178880 £0.35 each
Total is £635.04 retail with VAT
Mainfolds often come up for sale on eBay at between £150 and £170+postage.
The official Vauxhall labour time to replace the intake manifold is 3 hours. More labour may be charged if the cambelt is changed at the same time.
Assuming a typical labour rate of £70 per hour+VAT
(3 x 70) + 17.5% = £246.75 inc VAT.
Total including parts and labour - £746.17 inc VAT.
Further Information
The manufacturer of the intake manifold, Pierburg, has produced a technical service bulletin regarding the issues with the swirl flaps.
This bulletin can be found at http://www.ms-motor-service.com/ximages ... en_web.pdf
Video of the swirl flap check
Original thread can be found here: Thanks to Gairo on the West Midlands Vauxhall Owners forum
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Made it a sticky.
Originally Posted by Lao
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