[Spyro235]

As the title says, I'm considering replacing my swirl flap seals, to stem the leaking I have from there. Am I crazy? They're there apparently for low load efficiency, and that does really matter to me. a .5-1 mpg drop would be enough for me to replace the seals and keep them.

Does anyone see a drop, that truly tracks their mileage? I track every single mile on fuelly, and drive 40k miles a year right now. I tow a numch too, but I assume even towing at cruise isn't considered "low load," and therefore I'm not that worried about towing mileage changing.

[335dlci]

The only way to get new seals is to buy a new intake manifold......

[robnitro]

I think the only time they help is when you still have regen and egr. When the egr is being used, the mixture is not as lean, so having swirl evens out the combustion at slow speeds. This helps reduce soot build up in the dpf, making it need less regen.

Without egr, there's already a huge excess of air (oxygen) and the burn is fine.

Removing the flaps didn't affect the mileage of egr/dpf deleted cars from what I understand. It does effect those who still are stock.

[Spyro235]

Originally Posted by 335dlci

The only way to get new seals is to buy a new intake manifold......

Well, that's all I needed to hear. Blanks I'll buy!

Originally Posted by robnitro

I think the only time they help is when you still have regen and egr. When the egr is being used, the mixture is not as lean, so having swirl evens out the combustion at slow speeds. This helps reduce soot build up in the dpf, making it need less regen.

Without egr, there's already a huge excess of air (oxygen) and the burn is fine.

Removing the flaps didn't affect the mileage of egr/dpf deleted cars from what I understand. It does effect those who still are stock.

Good to know. I'm deleted and such, so I guess I'll operate on the "I hope I wont lose any efficiency" notion. Won't get around to it until my drift car is back together, but I'm not dripping on the driveway yet, so I don't care that much.

[335dlci]

Use the damn site for parts. Realoem.com

[RioPGTMN]

I highly doubt the swirl flaps will make a noticeable difference in mileage, while its all apart get everything as clean as possible.

[Persian Whisperjet]

Originally Posted by RioPGTMN

I highly doubt the swirl flaps will make a noticeable difference in mileage, while its all apart get everything as clean as possible.

I too had questions, but I did it at 70K and have zero zero change in mileage over the past 65K miles.

[Spyro235]

Originally Posted by 335dlci

Use the damn site for parts. Realoem.com

Always, I looked yesterday. #2 would be the seals, wouldn't they? Am I crazy?

https://www.realoem.com/bmw/enUS/sho...diagId=11_3876

[335dlci]

Originally Posted by Spyro235

Always, I looked yesterday. #2 would be the seals, wouldn't they? Am I crazy?

https://www.realoem.com/bmw/enUS/sho...diagId=11_3876

Just seals that meet the head at the manifold.

[Spyro235]

Originally Posted by RioPGTMN

I highly doubt the swirl flaps will make a noticeable difference in mileage, while its all apart get everything as clean as possible.

I'll clean it if need be, but at 242k miles, I doubt I've got much build up, if any. This car sat for a year that I know about, possibly 2. Which leaves the 242k miles it has to span 7 years of driving, mean sit has averaged 34k miles of driving for every year it was actually being used. I pulled the dealer records, and it had 60k miles in the first 2 years from brand new! The mileage, plus the fact hat its the heavier X5, leads me to think it'll have barely any buildup.

Originally Posted by Persian Whisperjet

I too had questions, but I did it at 70K and have zero zero change in mileage over the past 65K miles.

Good to hear. I'll likely just sold the prblem and block them off then, but I'm still undecided.

[Tambohamilton]

You probably won't see any change in fuel consumption from removing the flaps, but what you might notice is a drop in low RPM torque/power.

The swirl flaps are there not to restrict air flow into the cylinder, or to affect the AFR; they increase the velocity of the air entering the combustion chamber, which increases turbulence in the chamber, which in turn aids combustion by dispersing injected fuel faster - this is important when you have small amounts of fuel being injected (short injection duration, low injection pressure). The resulting burn will be cleaner with them, but I doubt you'd need to worry about dpf or egr if you remove the flaps.

Of course, if your car is an auto, you'll probably notice no difference at all.

I had a poor attempt at sealing mine with PU sealant last year...they're still leaking now. I think I could do it better, but I'm trying to think of other options for renewing the whole assembly rather than patching them up again. I don't want to fork out hundreds for a whole new manifold, and I don't want to remove the flaps!

[robnitro]

Removing flaps does affect the dpf because of extra soot at low loads or idle. You will have regens more often.

[Tambohamilton]

Is that speaking from experience?

[Nadir Point]

Originally Posted by Tambohamilton

Is that speaking from experience?

It's speaking from factual, proven diesel ICE engineering principles.

Would you like a signed affidavit from the automotive scientific community, or what?

[Tambohamilton]

Yeah, that'd be ideal, thanks!

[robnitro]

Not my experience but a few of the European members on e70 forums.

[Tambohamilton]

Cool, good to know

[Veton_335d]

I've had my swirl flaps deleted at 117k miles. The flaps looked to be in pretty bad shape so I'm glad I deleted them when I did. I've noticed no change in MPG or performance (some people claim a drop in low end torque)