2006 E60 525D - Deflapping : Swirl Flaps- The whole truth....maybe...

[Dynosaur]

Swirl flaps don't have oil anywhere near them, so you had other issues.

If you've ever had a leaking intercooler, you'll know just how much oil gets into the induction system.
It doesn't take a lot of mist to condense a good amount of oil at the flap spindles.
The engine consumes prodigious quantities of gas from the crankcase aswell as the atmosphere.

Other than which, the oil loss was entirely stopped by fitment of the blanking plates - indicating that all else was in good order.

[Jason_H]

My 535d definitely runs better at all speeds without the swirl flaps. I did 1,000's of miles with and now 1,000's of miles without.

[matthew_henson]

If you've ever had a leaking intercooler, you'll know just how much oil gets into the induction system.
It doesn't take a lot of mist to condense a good amount of oil at the flap spindles.
The engine consumes prodigious quantities of gas from the crankcase aswell as the atmosphere.

Other than which, the oil loss was entirely stopped by fitment of the blanking plates - indicating that all else was in good order.

But most of it stays in the Intercooler because it is cool so condensing the engine vapours with the oil and is the lowest point in the system.

I agree with others, removing the swirl flaps made no noticable difference to my car

[Jason_H]

This is the technical detail from BMW on swirl flap operation:

The adjustable swirl flaps are located in the tangential channels of the intake system and are opened and closed according to the operating status of the engine. The swirl flaps are closed under the following conditions:

* at low engine speeds and low injection volumes (map-controlled)

The swirl flaps generally remain open when

* the coolant temperature < 15°C OR
* the intake air temperature < 15°C

Effects of faults

If the swirl flaps stick in open position: Deterioration in exhaust gas characteristics in lower speed ranges otherwise no effect.

If the swirl flaps stick in closed position: Power loss of approx. 10% at higher engine speeds.

My assessment of this

If the flaps are open below an ambient of 15C and I drive to work in the morning and home in the evening then, in the UK, about 90% of my journeys are with the swirl flaps open. Therefore I'm better without them.

I ran a diagnostic with DIS on my exhaust backpressure after about 15k miles without swirl flaps and my DPF is as clean as a whistle. I can't remember the exact numbers but they were something like this: at idle the maximum allowed back pressure is 25mb, mine was 2mb. At 4000 revs the limit is 400mb mine was 20mb.

[jonnybgud]

I bought the 56-plate E60 525d of my sig some three months ago - and got a discount from the dealer because the swirlflap spindle seals were leaking copious quantities of oil.
And having read about the swirlflap liability, straight away replaced them with a shiny set of blanking plates.
Now I could sleep tight, safe in the knowledge that my pistons, turbocharger and DPF were safe from marauding chunks of ingested swirlflap.

Now, because the only time I'd driven it WITH swirlflaps was on the journey home from the dealer (before fitting blanks), I was never really able to make a flappy/deflapped driving comparison.
However, partial throttle openings always produced hesitancy and hunting. So after much research and head-scratching, I changed the EGR in desperation .... to no avail.
Changed the cam position sensor ... to no avail.
It was just as unsmooth as before - but fuel consumption was perfectly normal.

After further research, I read that someone who'd deflapped his own 525d found that he had no power downstairs - particularly compared to his wife's undeflapped 525d.
Further research revealed that the flaps are there to maintain gas-flow velocity into the combustion chambers when closed.
When the flaps are closed (which happens right up to c. 3,700 rpm), the fuel-air charge flows exclusively through the upper inlet ports.
The inlet manifold works rather like a twin-barrell carburettor and divides gas-flow into two separate routes : - under partial throttle, only one barrell is open - but at full welly, the second opens to allow heavy breathing.

So I bit the bullet, went down to see a chum at the local dealer's parts department and forked out more than £400's-worth of nuggets for a brand new manifold (which comes avec flaps) which I fitted this very afternoon.

WOO-HOOH!
What a difference.
I now have stock (rather than decidedly sub-optimal) performance and smoothness.
I'm now driving the BMW I'd always dreamt of with the full, creamy sixiness of silky, Bavarian wallop.
Pulls like a locomotive and when you get the full blast of both barrells, she's off like a rat up the proverbial drainpipe.

So my advice to everyone considering deflapping is not to.
If your flaps are getting a bit ropey and you want to maintain a beautiful drive, splash the cash and fit a new manifold.
It's about an hour and a bit's straightforward work for the DIY'er.
HTH.

I must admit I went down the same route on my 530d, and what you have said above is pretty much how my swirl flap story went only mine had the later type manifold fitted from new and managed 98k till it started to leak around the flaps. On inspection when removing, the flaps where all intact still, even the rubber jackets under all the crud.

One thing I did notice was the old manifold weighed almost twice as much as the new one, both the same part number but the new one didn't have 1kg of crud in it which the old one had, so the increased flow in the new inlet manifold due to lack of gunky crap my be why it gave your and my car a new lease of life...

[Dynosaur]

I must admit I went down the same route on my 530d, and what you have said above is pretty much how my swirl flap story went only mine had the later type manifold fitted from new and managed 98k till it started to leak around the flaps. On inspection when removing, the flaps where all intact still, even the rubber jackets under all the crud.

One thing I did notice was the old manifold weighed almost twice as much as the new one, both the same part number but the new one didn't have 1kg of crud in it which the old one had, so the increased flow in the new inlet manifold due to lack of gunky crap my be why it gave your and my car a new lease of life...

Sounds very possible, though I didn't notice a huge discrepancy in weight.
Given that so many found no difference after deflapping, it may be that I have a secondary issue - which I suspect may be injection pump.

When I got the car, there was an intermittent buzzing sound (though only at idle) coming from around the injection pump area - not easily pinpointed.
When I changed the fuel-filter (which had never been changed before - it was a lease-company owned car), the noise disappeared.

But it could be that 96K of unchanged fuel-filter resulted in damage to the injector pump.
Would it have been the pump itself intermittently buzzing ?

It's never thrown any meaningful error codes - only those associated with removing the intake manifold and rail sensors, which after clearing haven't returned.
That said, would low fuel pressure or an injection pump fault necessarily throw up any error codes ?

[biggurs]

I'm confused here, you got a discount on the purchase as the 'swirlflap spindle seals were leaking copious quantities of oil'
but there's no oil in the inlet manifold or around the swirlflap itself simply an oily type vapour which passes through the EGR valve
and builds up as an oily type deposit in the EGR/Inlet Manifold/Swirlflaps.

With what you've described I'd be more inclined to think think the inlet manifold had split in some way and thats why
a replacement has returned the engines performance to as it should be, at least it is now performing as it should.

At last... someone who speaks logically and with sense!

For the original poster>>> The best way to confirm whether de flapping was the cause of the flat spots and not the fact you may have had a faulty manifold in the first place is to deflap your new manifold and see if it makes any difference. At least that would settle the deflapping issue and if there is an immediate and noticeable problem due to deflapping then everyone on the forum will chip in a nugget and get you a new manifold! (or possibily a recon manifold, failing that then one from the scrappy)

[kwempe]

It is probably me that Dinosaur meant about the wifes car still be flap intact. I will probably still de-flap her car as I am paranoid about reliability (13 years as an AA patrol probably makes me this way). I can however confirm that a car with its flaps intact does actually have better low end power and I can drive them back to back any day. I really doubt this would notice on a manual box car as you tend to be above about 1800 rpm but on an auto and with BMWs stupidly over tall gearing, the gearbox can often get it wrong and try to pull too high a gear. Our cars? Mine an E60 530d and the wifes an E61 530d. Engine wise they felt identical until deflapped.
Mine now sports a Blufin map by Superchips that I can remove or put back on as it comes with a OBD compatible handset and that hasn't restored bottom end. I really am not too worried though, I either use DS mode on the box or change manually.
All this is not to say anybody is right or wrong really just how mine and the wifes car behave. The differance might not be so obvious in all cars or indeed all driving styles (booting it about the place I notice no loss of low end as the box gets used to faster driving).
Just a shame that BMW did not manage to make a fully reliable intake flap system. In fact I would even go so far as to say the engine might be a better one with 12 less valves.........anybody ever owned or driven or even raced against a MK4 Golf GT TDI? 1.9 litres, 130 bhp + 8 valves and probably the torque-est engine I have ever owned or driven. Traded up to a 2.0 tdi in an Audi A3 (140 bhp +16 valves) and it felt like it was towing an anchor by comparison.

[Dynosaur]

Given the lack of difference folk have noticed between flapped/deflapped performance, I'm inclined to thiink that I have a secondary issue that's largely been masked by the manifold replacement.
Now, when I got the car it was making this noise at idle (mostly after the throttle is blipped) : -




.... which stopped after I changed the fuel-filter for the first time in the car's life at 96K (lack of servicing by the previous lease-hire company owner).

Any idea as to what might have been emitting the intermittent buzzing (most evident towards the end of the video) ?

[matthew_henson]

Sound like an air leak to me but could be wrong... the high pressure CRD pump is located inside the engine block and is driven off the crankshaft so it difficult to hear a fault with that.

Have you checked all the induction pipes to and from the intercooler? and the intercooler itself?