diesel engine, logical swirl flap fix?
 

i've been looking at the controversial swirl flap design on the E46 motors, this is a swirl flap for those that down know, it sits in each inlet manifold, all connected to a arm thats attached to a servo.
Attachment 8670

the fault is that the flap made is made of week plastic that deteriorates and breaks down resulting in it going into the cylinder, or the 2 machine bolts come loose resulting in the flap and bolts going down into the cylinder. picture of a failed one
Attachment 8669

Mej sent me a link to a company that provides blanking plates so you can take the whole assembly out and block the hole, but they are £14 + vat each (how about nooooooooo). been trawling the interwebs all evening trying to find sizes for them as i could get them made for free but couldn't find them. bloke on ebay is selling them individually for 6 quid so i could buy one and have it coppied, but.........
Attachment 8671

this is what i cant seem to understand, I've not taken them out yet and had a look but to me, why couldnt you just take the two bolts out, remove the flap and put the assembly back into the manifold? :confused: or or cut of the arm?. am i missing some grand design plan here? can anyone see why that wouldn't work?

i know its not a car place but the BMW forums are full of crap

Re: diesel engine, logical swirl flap fix?
 

Why are they there if not needed?

Re: diesel engine, logical swirl flap fix?
 

they lower the emissions slightly and i think they improve boost pressure a tiny amount, but most people have said they don't notice any difference when they're gone, nor have the emissions been flagged up on MOT's

Re: diesel engine, logical swirl flap fix?
 

you could if you filled the hole where the shaft goes threw with JB Weld.

Re: diesel engine, logical swirl flap fix?
 

Well I was thinking not even gojng thay far, just taking off the flap and two machine bolts leaving the shaft there, only thing I can see it affecting is fueling but just having a shaft there cant effect it anymore than having nothing there what so ever. Going to have a closer look at them at the weekend, I reckon thread lock and some epoxy should suffice.


Just all seems odd that peoples first reaction is to pay 60 quid on parts that's not even authentic BMW parts, when you don't have to. Some have even paid 400 quid for a new designed manifold from hem that gets rid of the swirl flaps completely

Re: diesel engine, logical swirl flap fix?
 

If I read this correct they are on induction air?[Sorry don't know that particular engine] and would probably assist in the air atomised fuel mix in the chamber giving better ignition,cleaner and less carbon deposit in the chamber with a even air intake to all cylinders.Yes the engine would probably run reasonably well without them but more than likely a lot better with them.
Lots of engines have bits on them that they can run without but in my experience they are usually there for a good reason,be it efficiency,emissions,cooling,air fuel mix whatever.

Re: diesel engine, logical swirl flap fix?
 

Any idea on how to better fix them to the arm? I'm thinking thread lock and epoxy over the head and bottom of the machine bolt. They're the only thing I'm particularly worried about going through the system (for obvious reasons). I reckon the plastic breaking up would just pass through

Re: diesel engine, logical swirl flap fix?
 

Turbo blades are metal and can cause severe problems when they break up but as these are plastic I would imagine that any plastic fragments would melt and burn off due to the heat of the ignition,possibly why they are plastic in the first place.I dont know how they are fixed but providing that they are secure what is the problem as they are a static fixing

Re: diesel engine, logical swirl flap fix?
 

buy my petrol one it doesnt need this mod :)

Re: diesel engine, logical swirl flap fix?
 

Swirl flaps breaking have caused major damage to numerous BMW engines. They don't just start breaking up into tiny bits, the whole flap parts company with the spindle and gets ingested. It's a very well known problem, and not only on BMWs.

The flaps are only effective under very light load (low boost) conditions where soot generation is more prominent. Removing them may have a small impact on economy and driveability at low speeds, but most people don't notice a great deal of difference.