5 replies to this topic

[guitar]

This topic is well covered in the mk3 section concerning inlet manifold swirl flaps.

I have a Mk4 2009 Duratec 2.0 and there was the tapping sound,
though I did not do anything about it yet, then last week an engine warning light

It is still under extended warranty so Ford have replaced the solenoid that controls the flaps and now it goes well with no tapping sound yet.

When the warranty runs out (when the car 8 years old in September) I plan to remove the flaps or have them removed for me.

There are lots of how-to videos about the mk3 but it looks to me like my Mk4 has a slightly different shape manifold, and the Haynes manual says to to remove the manifold the engine mounts have to be removed then replaced with new screws when it is put back on, and that is something I am not confident about doing myself.

Has anyone removed the inlet manifold on a Mk4 Duratec and is it any more complicated than on a mk3?

Edited by guitar, 01 February 2017 - 08:44 PM.

[RB2004]

You can only remove half the flaps on mk4 unlike mk3

Reason being is mk4 has 2 sets of flaps.. Tumble flaps and inlet manifold runner control flaps.

The later is installed in the manifold before its welded together so you can't remove them.

So even if you remove 1 set there will still be another set remaining.


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[vieplis]

A couple of images attached to illustrate this explanation

You can only remove half the flaps on mk4 unlike mk3

Reason being is mk4 has 2 sets of flaps.. Tumble flaps and inlet manifold runner control flaps.

The later is installed in the manifold before its welded together so you can't remove them.

So even if you remove 1 set there will still be another set remaining.

and this explanation (from http://www.talkford....revs/?p=2552442)

Mk4 mondeo has 2 sets of flaps, imrc and tumble flaps.

Check the swirl flaps are working correctly.

At lower revs should be using the longer inlet tract, but at higher revs should be using the shorter tract.

If for some reason the solenoid is stuck and it's using shorter Tract at lower revs then that can cause problems

 

 

[guitar]

Thanks a lot I see the difference now.

They seem to be working fine now as before the new solenoid I was getting about 28mpg and now up to 36mpg.

For long term reliability is it advisable to leave the upper flaps as they are or would removing them be a worthwhile thing to do?

[RB2004]

Thanks a lot I see the difference now.

They seem to be working fine now as before the new solenoid I was getting about 28mpg and now up to 36mpg.

For long term reliability is it advisable to leave the upper flaps as they are or would removing them be a worthwhile thing to do?

Regardless of popular opinion removal is a personal choice.

However slight, the flaps are engineered for a purpose, ford spent millions designing, prototyping and testing them.. So they clearly serve a purpose.

Ford aren't in the habbit of chucking money developing useless components.

However there are lots of people who say removed with no issues.

What it boils down to is, do you trust ford engineers and all of their testing and development data, static dyno testing; flow bench testing which we aren't privvy to.

Or do you trust somebody on the Internet who thinks they know better than the car manufacturer posting saying they removed them without causing any problems, without any testing carried out or data to support their claims?

As above all down to personal choice

What my own independent findings have been is that they fail when the piston rings allow excessive blow by into the sump, it causes oil to spit into the oil separator and despite the separators purpose being to separate the oil, once the blow by gets too much it overwhelms the oil separator and oil ends up in the inlet manifold.

That was one reason why ford modified the oil separator and increased the size of the PCv hose, the modified separator had extra baffles and the PCv hose was to allow for a lower crankcase pressure, if you can evacuate the gases / vapour quicker it will be at a lower pressure... Lower pressure should in theory mean less oil spitting as less pressure to force the oil out.

Probably one reason why later cars tend to be a bit more reliable on flaps, although I have seen them fail on mk2 focus just the same. But less common at the moment...
Maybe as the engines get older it will become more common.

But the link between oil and failure is, the oil is not clean oil, it has carbon in suspension from the exhaust blow by, this coupled to heat leads to a gumming up effect on the flap bearing surfaces and it gradually wears it away as a result.

Ford didn't help the cost cutting measures either, manifold is designed to take 3 bearings between the ports, on mk3 mondeo they was originally only fitting 2 and on mk4 mondeo they removed them completely. Leaving it inadequately supported.


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[Christiaan]

Hi,

Swirlflaps failing on a mk4 Duratec Mondeo is virtually non existent.

Having owned a MK3 2.0 petrol and swapping the inlet manifold as a precaution on that car, I thought IT would be the same on my mk4 Mondeo 2.3.

But my Ford dealer stated that this wasn't the case. Only solenoids and actuators and sometimes pcv give problems.

To prove this fact he showed me that they hadn't a single inletmanifold dit these engines in a very very long time.

Christiaan

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