Swirl flaps - are they worth it?

**mhobson** · 26-07-2015,04:56 PM

After I had the inlet manifolds changed on both cars there was no noticeable difference in fuel consumption, however, as I understand it in the UK, if your orange MIL engine warning light is illuminated that is an MOT fail. As well as that, my concern was that with the MIL already illuminated, should another issue arise I would be unaware that the new problem was there which could have caused the engine long term damage. The reason for a lot of these seemingly petty engine modifications is to shave fractions off the CO2 emissions so that the car can be in as low bracket as possible so the tax implications for those fortunate enough to have company cars supplied, will choose one car over another, leaving the ensuing issues for people like me who buy the cars secondhand.

**MarkTM** · 26-07-2015,07:25 PM

Originally Posted by mhobson

as I understand it in the UK, if your orange MIL engine warning light is illuminated that is an MOT fail.

Not true!

Also as I scan mine weekly I'd be spotting any additional issues before they become serious.

I believe that my emissions test in June resulted in less than half that permissible, and only 0.1 higher than when the flaps worked

**mhobson** · 26-07-2015,09:06 PM

Originally Posted by MarkTM

Not true!

Also as I scan mine weekly I'd be spotting any additional issues before they become serious.

I believe that my emissions test in June resulted in less than half that permissible, and only 0.1 higher than when the flaps worked

I was told that from either this or last year the MIL was being included in the MOT, maybe I was advised wrongly, however I very much doubt that the majority of VAG owners will be scanning their cars on a weekly basis, the light is there for a good reason and may disclose a fault which may have costly consequences to the average driver.

**ats4603** · 30-11-2015,08:26 PM

I got an "Advisory" for having the MIL light on at the last MoT on my Touareg, but it still passed...

**MarkTM** · 30-11-2015,08:51 PM

Originally Posted by ats4603

I got an "Advisory" for having the MIL light on at the last MoT on my Touareg, but it still passed...

It perhaps might help if you shared when this was?

**ats4603** · 30-11-2015,09:07 PM

Shortly before 20 September 2015...

**dtoru** · 15-05-2016,03:44 PM

can the flap motors not be mapped out using winols to stop eml light coming on the find away to physically remove them?

**SRT88** · 16-05-2016,09:17 PM

Originally Posted by dtoru

can the flap motors not be mapped out using winols to stop eml light coming on the find away to physically remove them?

VAG decided they are worth, so they have put it in almost every engine they have manufactured lately.
Are you going to feel the difference if you map them out? Well this is a more difficult question to answer. For sure your bottom/lower end will be more sluggish - if you normally start to feel the torque kicking in at as low as 1950-2050rpm, after mapping them out you will shift the graph ~200rpm to the right. There will be no difference at full throttle/kick down because the native operation of the swirl flaps suggest that they are progressively opened up until 2700rpm. Above that point there is a full boost in the manifold, therefore they are fully open.

**Not_Anumber** · 03-06-2016,09:54 AM

Can the swirl flaps be mapped out ? I am about to have a remap done so it would be useful to know if this can be done as part of that.

**SRT88** · 03-06-2016,10:54 AM

Originally Posted by Not_Anumber

Can the swirl flaps be mapped out ? I am about to have a remap done so it would be useful to know if this can be done as part of that.

The fault code could be mapped out, however the swirl flaps will be fully opened all the time (emergency mode/full throttle mode). If they are stuck closed or have too much play in the shaft/bushings, rev hunt will be an intermittent problem.
Regards