What does this do
- Thread starter MR BLACK
- Start date
Is it 7 on here?
http://bmwfans.info/parts/catalog/E85/Roadster/Europe/Z4_3.0i-M54/RHD/N/2003/november/browse/engine/intake_manifold_system/
http://bmwfans.info/parts/catalog/E85/Roadster/Europe/Z4_3.0i-M54/RHD/N/2003/november/browse/engine/intake_manifold_system/
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Found this
I just wanted to share a recent "discovery" and increase in the number of vehicles found with faulty DISA. Only one vehicle had resulted in replacing the complete engine. This is just in my shop. I'm sure other techs and owners here had this experience already.
The flap is powered close, controlled by the DME. Most of you who aren't familiar with the resonance system, here are some words of wisdom :
----> The resonance system provides increased engine torque at low RPM, as well as additional power at high RPM. Both of these features are obtained by using a resonance flap (in the intake manifold) controlled by the DME.
During the low to mid range rpm, the resonance flap is closed. This produces a long/single intake tube for velocity, which increases engine torque.
During mid range to high rpm, the resonance flap is open. This allows the intake air to pull
through both resonance tubes, providing the air volume necessary for additional power at
the upper RPM range.
When the flap is closed , this creates another "dynamic" effect. For example, as the intake
air is flowing into cylinder #1, the intake valves will close. This creates a "roadblock" for the rushing air. The air flow will stop and expand back (resonance wave back pulse) with the rushing air to cylinder #5. The resonance "wave", along with the intake velocity,
enhances cylinder filling.
The DME controls a solenoid valve for resonance flap activation. At speeds below 3750
RPM, the solenoid valve is energized and vacuum supplied from an accumulator closes
the resonance flap. This channels the intake air through one resonance tube, but increases
the intake velocity.
When the engine speed is greater than 4100 RPM (which varies slightly - temperature influenced), the solenoid is de-energized. The resonance flap is sprung open, allowing flow through both resonance tubes, increasing volume.
The problem I have seen with the part is that the metal pin that holds the flap together comes apart falling out of it's place. Not only does the flap stops working, the pin can fall down into the combustion chamber and finds its way in between the valves and the piston creating HAVOC. Valves can bend and the cylinder walls can be damaged when the pin falls off. I am not sure if fuel quality, aggressive driving, and other factors possible are causes for this to happen. One thing is for certain, engines with this problem has sludge/dirt/carbon deposits around the adjusting unit that failed. So it may not be a bad idea to check this, on high mileage hard working M54 engines or any 6 cylinder engines with this intake system (including M52TU).
Attached Thumbnails
Found this
I just wanted to share a recent "discovery" and increase in the number of vehicles found with faulty DISA. Only one vehicle had resulted in replacing the complete engine. This is just in my shop. I'm sure other techs and owners here had this experience already.
The flap is powered close, controlled by the DME. Most of you who aren't familiar with the resonance system, here are some words of wisdom :
----> The resonance system provides increased engine torque at low RPM, as well as additional power at high RPM. Both of these features are obtained by using a resonance flap (in the intake manifold) controlled by the DME.
During the low to mid range rpm, the resonance flap is closed. This produces a long/single intake tube for velocity, which increases engine torque.
During mid range to high rpm, the resonance flap is open. This allows the intake air to pull
through both resonance tubes, providing the air volume necessary for additional power at
the upper RPM range.
When the flap is closed , this creates another "dynamic" effect. For example, as the intake
air is flowing into cylinder #1, the intake valves will close. This creates a "roadblock" for the rushing air. The air flow will stop and expand back (resonance wave back pulse) with the rushing air to cylinder #5. The resonance "wave", along with the intake velocity,
enhances cylinder filling.
The DME controls a solenoid valve for resonance flap activation. At speeds below 3750
RPM, the solenoid valve is energized and vacuum supplied from an accumulator closes
the resonance flap. This channels the intake air through one resonance tube, but increases
the intake velocity.
When the engine speed is greater than 4100 RPM (which varies slightly - temperature influenced), the solenoid is de-energized. The resonance flap is sprung open, allowing flow through both resonance tubes, increasing volume.
The problem I have seen with the part is that the metal pin that holds the flap together comes apart falling out of it's place. Not only does the flap stops working, the pin can fall down into the combustion chamber and finds its way in between the valves and the piston creating HAVOC. Valves can bend and the cylinder walls can be damaged when the pin falls off. I am not sure if fuel quality, aggressive driving, and other factors possible are causes for this to happen. One thing is for certain, engines with this problem has sludge/dirt/carbon deposits around the adjusting unit that failed. So it may not be a bad idea to check this, on high mileage hard working M54 engines or any 6 cylinder engines with this intake system (including M52TU).
Attached Thumbnails
Yep, that is the vacuum controller for the resonant intake flap in the manifold as far as I can gather.
Didn't a user the other week have their manifold ends blown off after this bunged up!?
Mine rattles a very little bit, well not a rattle, more a rattly breathey air flowing kinda noise, I think it resonates at around 1750rpm.
I'd take it off and give it a clean inside/out, or just replace (I think the part was about £25 or under so not too bad, and apparently was a common failure point from the other persons post where it blew up their manifold!)
Dave
Didn't a user the other week have their manifold ends blown off after this bunged up!?
Mine rattles a very little bit, well not a rattle, more a rattly breathey air flowing kinda noise, I think it resonates at around 1750rpm.
I'd take it off and give it a clean inside/out, or just replace (I think the part was about £25 or under so not too bad, and apparently was a common failure point from the other persons post where it blew up their manifold!)
Dave