Technical Swirl flaps

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Technical Swirl flaps

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Jan 5, 2010
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Has anyone had problems with the flaps on the inlet manifold? Mine occasionally stick and I get loss of power and lots of smoke (no DPF). It only seems to happen when the fuel is at its richest (first thing or under load up a long hill). It's a common fault on most modern diesels, especially BMW's and Vauxhalls. A popular mod is to remove the flaps altogether, but typical Fiat, it's a big job!

To test the theory, I bypassed the Swirl actuator so that the flaps are permanently open. The results are amazing - the car is so much smoother and revs and picks up much better. The problem with the Auto box is that the car rarely goes over 2000 revs so the flaps are shut most of the time. I am going to run it for a few weeks before I consider removing them totally though.
 
Personally I've not had an issue with swirl valves/flaps (SV).

I have heard/read that the ECU measures the time taken to move the flaps from closed to open and back and any error is flagged. I've also heard that jammed/frozen valves can damage and/pr misalign the swirl valve actuator.

My understanding is the swirl valves (SV) provide that little extra power and response at smaller throttle positions. If you are a more performance driver then the SVs will possibly not by you much as by definition as a performance driver you will be higher rpm, on cam, and gunning to top end. For those that potter around town, in traffic and expect the occasional quick pick-up the swirl valves will be of an advantage.

One thing Fiat swirl valves do not do is drop nuts off into the intake and cylinders causing much damage. I gather some BMWs (and others) are prone to this.

As much as I appreciate the modern diesel engine it has really only got to where it is in the car performance stakes v's a petrol engine due to loads of smart engineering "gizmos".

All these "gizmos" have their plus and minus points and oddly the marketing hype about any particular "feature" is often dressed up in "smart speak" to fool or win over the punter.
 
I finally got around to disconnecting my swirl flaps this afternoon and the difference is remarkable! Thank you Greg123, I tied them off to the union as you suggested (now that was fun) and took it for a test drive. Everything Greg123 said about being smoother, quieter and more responsive also happened to mine. Mine was very course above 3k but now it's much quieter and smoother! I am struggling with the logic though, because the valves would normally be open at those revs anyway. Next job is to take the manifold off, completely remove the flaps and thoroughly clean the inside. Looks like quite a long winded job, plus I'm not sure how best to blank off the holes that will be left where the linkage was.
 
Hi s130, access to disconnect the linkage is pretty easy. It's just under the egr valve (on the 2.4) and you can get a pry bar or large screwdriver in there ok. Just make sure you have a decent light and approach from the cambelt end. Gently prise the ball joint off the end of the linkage. Then I just made sure that the valves were pushed as far as possible to the left (anti-clockwise) and tied the far left hand pivot to the rigid water union to the left of it, which was the fiddliest part. Not ideal from an engineering perspective but effective none the less. They didn't appear to go round any further than they were when they were connected.
 
Thanks

Not sure at the moment if the 1.9 16V engine is the same baisic layout as the 2.4.

Approaching from the cam belt end is one hell of a long reach to No.3 inlet tract.

Also on the 1.9 engine there is a vacuum revoir device (blockage) located at intake 2 that I'm pretty sure would block access to No.3 and the actuator.

Anyway, your have clarified some stuff so thanks for this.
 
if the later 1.9/16v dont have flaps? wont it be easier to get hold of a later clean manifold?

No flap drive/linkage/brackets that I could see on ePER when I looked for somebody. However changing the inlet manifold is an 8 hour job. Also you are still going to have to have the swirl valve actuator connected to the ECU unless you get a remap.

For most disconnecting the drive linkage is going to be a lot cheap and easier to do.
 
Do we Croma 1.9 16V owners want the bad news or the bad knews.

After several hours of probing and looking I finally visually located the bottom of swirl valve number 3 and the end of the linkage that drives it. As for accessing the actuator itself then forget it. It is mounted behind the vacuum tank which is mounted on a plate at the back of the engine block. There is no access without removing the vacuum tank and to remove this is no small task. Requires system draining, fixed pipe removals and is a very fiddly job. I think this tank removal was what contibutes to the 8 hour marathon in changing the inlet manifold.

Just to see the bottom of No:3 I had to remove some of the oil vapour/vacuum recovery hoses at the rear of the block.

I could get a screw drive on the end of the valve/linkage BUT WARNING! the drive at this point appears to be a rotating vertical link so any attemp to pop the link off is probably likey to damage the drive motor.

I'm not going to mess with mine till I can actually see all the components either in a picture taken of a 1.9 manifold with components attached or I get bored and decide to bite the bullet and start a major stip down.

Another concern I have without access to the driven/motor ends of the linkage is the space behind here is very very tight and there is a good possibiliy that with the linkage still attached to the drove motor the free eng will still be moving around and could possibly catch on the back of the block or some other ridge/depression of other item and then the motor could be overloaded. This will certainly then throw and ECU error and from there on will be uncharted territory.
 
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Note sure my flaps are working anyway. A test while reving the engine in neutral from idle either smoothly through the range to 4000krm or blipping through the range does not appear to move the bar. On can only just see a tilt in the bar as though it wants to move but this is all.

Could be that one needs real load and vacuum on the engine to really activate them.

Now a question for anybody to confirm / correct.

When the engine is powered off are the swirl flaps in the fully open position, then move to closed / modulated in the 1K to 2 or 3K rpm range and are fully open again are higher rpm? I have read this somewhere before and have quoted it myself but am now a little puzzled / confused.

Over to the experts.

Just seen this video of the Vectra manifold and it definitely looks like the flaps are fully OPEN in the rest position ( ) which is good news. i.e
my ball joints are always far left positioned.
 
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When the engine is off, the flaps are in the open position. Once the engine is at idle they close. Then they open as you rev past 2k. Mine opened and closed whilst he car was stationary. If your bar is tilting it sounds like your actuator is working but a flap(s) is jamming them so they won't operate. That creates two problems, first the strain on the actuator and the other being whether they are permanently open or closed!
 
And a slightly more worrying question is why the actuator has not signalled a failure to the ECU. My understaning is that the actuator is a smart learning device which learns what is required to move the valves and also the typical times taken for valve deflection.

So if the above is true then I should be getting ECU errors by now, UNLESS, the valves are seized and the ball joint link has dropped of at the actuator end. But if that is the case then this does not explain why the top linkage bar can be seen to tilt when the engine is revved.

Odd, very odd!

The only other explanation I can come up with is that Fiat did a late ECU update (my car was produce in Sept 2005, purchased in Dec 2006) which was applied during manufacturing or as a required/manditory update prior to vehicle sale. I don't have access to SIGI to check out if there were any ECU updates to the Croma. Such an update could knoble or drastically reduce the valve operation. Also as we know Fiat have removed swirl valves from the later generation diesel engines.

A quick ECU update depsite the vehicle still having all the hardware would be an effective way of reducing warranty claims on high mileage within warranty vehicles.

Does your head hurt? Mine does......nothing seems to be straight forward anymore!
 
I took my 2.4 to Fiat and paid for an hour (trade, luckily) last week for them to check the car's ecu's and apply any updates. Answer - no updates available. Now this may be true, but as I'm about to pull the engine ECU file and start doing things like DPF removal, EGR disable when warm and remap - it would be nice to have this confirmed.

And a slightly more worrying question is why the actuator has not signalled a failure to the ECU. My understaning is that the actuator is a smart learning device which learns what is required to move the valves and also the typical times taken for valve deflection.

So if the above is true then I should be getting ECU errors by now, UNLESS, the valves are seized and the ball joint link has dropped of at the actuator end. But if that is the case then this does not explain why the top linkage bar can be seen to tilt when the engine is revved.

Odd, very odd!

The only other explanation I can come up with is that Fiat did a late ECU update (my car was produce in Sept 2005, purchased in Dec 2006) which was applied during manufacturing or as a required/manditory update prior to vehicle sale. I don't have access to SIGI to check out if there were any ECU updates to the Croma. Such an update could knoble or drastically reduce the valve operation. Also as we know Fiat have removed swirl valves from the later generation diesel engines.

A quick ECU update depsite the vehicle still having all the hardware would be an effective way of reducing warranty claims on high mileage within warranty vehicles.

Does your head hurt? Mine does......nothing seems to be straight forward anymore!
 
Happy to help!

Mine is still running better as a result. I do however want to remove the manifold when I do the cambelt and clean it/remove the flaps/plug the spindle bores. I'll clean up the EGR (I have an ultrasonic tank) at the same time and put everything back together clean, shiny and without any swirl flaps/spindles.

Still not too sure why they had them when later engines don't and they run better disconnected....

I finally got around to disconnecting my swirl flaps this afternoon and the difference is remarkable! Thank you Greg123, I tied them off to the union as you suggested (now that was fun) and took it for a test drive. Everything Greg123 said about being smoother, quieter and more responsive also happened to mine. Mine was very course above 3k but now it's much quieter and smoother! I am struggling with the logic though, because the valves would normally be open at those revs anyway. Next job is to take the manifold off, completely remove the flaps and thoroughly clean the inside. Looks like quite a long winded job, plus I'm not sure how best to blank off the holes that will be left where the linkage was.
 
Permanently open as far as I can tell.

I think I may need to tie a very fine piece of cotton (or wool strand) to one of the holes in that actuator bar and see if it gets broken by actuator movement.

If the valves are siezed then I'm sure the actuator / ecu would have complained by now. My passed research suggests that the actuator is self learning and measures the time for valve movement/position transition.

Meanwhile I have no errors, failures etc.

Puzzled. I am.
 
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