DISA replaced and rattling noise gone! potential disaster averted!

I've had the rattling noise for a while and at first I thought it was the VANOS, but after further research and reading the 330i doesn't suffer from the VANOS rattling noise. I actually went as far as buying all the gaskets to do the VANOS seal replacement until I realized it was the DISA making the noise.

Fast forward to today:

Here are a few pics of the DISA removed from the car.


as it came out of the car. notice the pin has work itself out about 1/3 of it's length!!!!!



the flap was not perpendicular + like it should be and generally really really dirty.





close up of the pin... scary.


the flap had a lot of movement in it. about 1/4" before any resistance was felt. the new one was perfectly centered + and wasn't as easy to move as the old one.

Thanks again to bimmerfest for potentially saving me from having to pay for a new engine

Wow that's a scary looking part. How much mileage is on your 330i? Was the DIY difficult?

Wow, that's crazy. +1 on what the mileage is.

Originally Posted by Solidjake

Wow, that's crazy. +1 on what the mileage is.

True. These cold weather part failures, as well as worn part threads is getting me paranoid. I think Inspection II for me is gonna be an overboard of more than required thing for me.

Originally Posted by av98

Wow that's a scary looking part. How much mileage is on your 330i? Was the DIY difficult?

current milage is 168K but the noise probably started around 150K or so. I shouldn't have ignored it for so long. I could have paid the big price. I read (here in fact) of someone having the pin back out completely and be swallowed up by the engine = kaboooom

the DIY was fairly easy for me. took me about 15mins total. I had to make another extension to be able to reach the T40 bolts (also taped so they don't come apart). I also had to disconnect the intake tube and push it down so I can get at the 2nd bolt and remove the DISA. Part was a little expensive ($183 with shipping from Tischer) but to think what could have happened if the pin worked itself loose and into the engine.... Well, like I said, I saved money (and potentially the engine)

Originally Posted by Solidjake

Wow, that's crazy. +1 on what the mileage is.

see above.

Originally Posted by Gryphon

True. These cold weather part failures, as well as worn part threads is getting me paranoid. I think Inspection II for me is gonna be an overboard of more than required thing for me.

I would just listen for the rattling noise. At least this one is an easy DIY

I'm gonna take a look at my engine bay and see what I hear. It is expensive, lol. But it needs to be changed regardless.

Is there enough room inside the intake manifold for the pin to wriggle free and get into the engine? The pin on my car's DISA unit came out completely while I was removing it from the manifold last year, and I spent several tense minutes locating it in the engine bay. After retrieving the pin, I cleaned it off, pushed it back into the flap, and reinstalled the DISA unit.

Since the DISA unit slides into a channel between the two halves of the intake manifold, I have my doubts that the pin would even be able to get loose in there and do a tap-dance inside one of the cylinders - but I'd like to hear from someone who has studied the system more thoroughly.

Originally Posted by G. P. Burdell

Is there enough room inside the intake manifold for the pin to wriggle free and get into the engine? The pin on my car's DISA unit came out completely while I was removing it from the manifold last year, and I spent several tense minutes locating it in the engine bay. After retrieving the pin, I cleaned it off, pushed it back into the flap, and reinstalled the DISA unit.

Since the DISA unit slides into a channel between the two halves of the intake manifold, I have my doubts that the pin would even be able to get loose in there and do a tap-dance inside one of the cylinders - but I'd like to hear from someone who has studied the system more thoroughly.

someone posted that exact thing happening to him. I don't remember if it was here or e46fantatics. my pin slide in and out fairly easily so I'm sure given enough vibration and time it could have come out completely.

in my case I had to replace the disa as it was completely worn.

If and when I ever replace the DISA valve, I`m gonna take a copper pipe cap, maybe 3/4 inch, or whatever is a close fit over that pin boss, and epoxy and/or drill & safety-wire that sucker to the boss to prevent the pin from coming loose....

Originally Posted by Fast Bob

If and when I ever replace the DISA valve, I`m gonna take a copper pipe cap, maybe 3/4 inch, or whatever is a close fit over that pin boss, and epoxy and/or drill & safety-wire that sucker to the boss to prevent the pin from coming loose....

Werd
MacGyver school of engineering FTW!

what does the DISA valve do and what are the symptoms of a faulty one? I have the fog horn sound after power down and excess white exhaust and am getting the oil seperator changed next week..Can anyone give me an estimate for how long it should take an experienced BMW mechanic to do the labor on an oil seperator?

What does DISA do anyway?

Originally Posted by DaShoker

What does DISA do anyway?

found this in my search:

To be exact, the DISA valve does not change the length of the intake system on the six-cylinder engines from the M52TU onwards - its function is to be open at low speeds, so feeding all six intake pipes together.

At mid-range speeds it closes, seperating the front and rear groups of three cylinders from each other. At higher speeds it opens again, joining the cylinder groups together. It therefore acts like a massive balance pipe which can be closed when required.

The effect of this is to give more mid-range torque without interfering with bottpm and top-end torque.

Originally Posted by dakarm

found this in my search:

I've been searching for a good (read "simple") explanation of the DISA valve operation and this is the BEST I've found!

Thanks.

To show my appreciation, I added it just now to the VERY best of E39 Links as a re-use reference (and that's the best compliment of all).

- DISA VALVE FLAP BREAKS: the DISA valve flap breaks, sometimes with parts sucked into the intake manifold (1) (2) (3) (4) (5) (6) (7) (8) or the disa valve o-ring fails (1) (2) & where to get just the DISA valve o-ring (1)

Originally Posted by dakarm

found this in my search:
To be exact, the DISA valve does not change the length of the intake system on the six-cylinder engines from the M52TU onwards - its function is to be open at low speeds, so feeding all six intake pipes together.

At mid-range speeds it closes, seperating the front and rear groups of three cylinders from each other. At higher speeds it opens again, joining the cylinder groups together. It therefore acts like a massive balance pipe which can be closed when required.

The effect of this is to give more mid-range torque without interfering with bottpm and top-end torque.

I think that explanation is wrong, based on this explanation:
- m54x5[1].pdf

Originally Posted by rdl

- Pages 42 -44 describe DISA operation
below ~ 4000 RPM closed
above ~ 4000 RPM open
rest position, i.e. when removed - flap open

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 ECM.

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 in rushing air. The air flow will stop and expand back (resonance wave back pulse) with the in rushing air to cylinder #5. The resonance "wave", along with the intake velocity, enhances cylinder filling.

The ECM 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.

Note: With 12 volts DC to the DISA valve, the 'magnetic valve' closes the DISA flap; when you remove the 12 volts DC, the DISA flap flips back open due to spring tension.
- Strange results from a simple test of the M54 DISA valve today

Originally Posted by Fast Bob

If and when I ever replace the DISA valve, I`m gonna take a copper pipe cap, maybe 3/4 inch, or whatever is a close fit over that pin boss, and epoxy and/or drill & safety-wire that sucker to the boss to prevent the pin from coming loose....

Would you really???....

I have always thought of you as very proper and right-way-kinda-guy when it comes to Bimmer repairs.


..but then a little relieved

It would be nice for those of you who replace your DISA, to confirm the new information we're finding about the DISA 12-volt magnetic solenoid and the 1/16" hole that allows vacuum to accumulate to open the flap when the 12 volts uncovers the one-way check valve.

Sadly, to my knowledge anyway, NOBODY (to date) has adequately explained HOW the DISA actually works!

Luckily, the knowledge has been growing exponentially lately, and is scattered about, but should be summarized here:

• - E46 (1999 - 2006) > Do you know WHY the M54 DISA has BOTH a vacuum accumulator AND a magnetic solenoid?

Here are the scattered research bits:

• - Strange results from a simple test of the M54 DISA valve today
• - When does the intake manifold adjustor (DISA Valve) close?
• - How the DISA Works
• - DISA Autopsy
• etc.

Would anyone know, is the DISA not included in the 2002 e39 touring (525iAT)?

Turner Motorsports indicates the sedan has the DISA for 2002 (my mfg date is 8/31/2001), but that the wagon doesn't. Seems odd.

Thanks to anyone who can share some light.

Tom

Originally Posted by tborden

Would anyone know, is the DISA not included in the 2002 e39 touring (525iAT)?

Turner Motorsports indicates the sedan has the DISA for 2002 (my mfg date is 8/31/2001), but that the wagon doesn't. Seems odd.

Thanks to anyone who can share some light.

Tom

Any 2.5, 2.8, or 3.0 motor with dual VANOS will should have a DISA.

Originally Posted by tborden

Would anyone know, is the DISA not included in the 2002 e39 touring (525iAT)?

Turner Motorsports indicates the sedan has the DISA for 2002 (my mfg date is 8/31/2001), but that the wagon doesn't. Seems odd.

Thanks to anyone who can share some light.

Tom

Yes, your engine has a DISA valve.

Originally Posted by dakarm

current milage is 168K but the noise probably started around 150K or so. I shouldn't have ignored it for so long. I could have paid the big price. I read (here in fact) of someone having the pin back out completely and be swallowed up by the engine = kaboooom

the DIY was fairly easy for me. took me about 15mins total. I had to make another extension to be able to reach the T40 bolts (also taped so they don't come apart). I also had to disconnect the intake tube and push it down so I can get at the 2nd bolt and remove the DISA. Part was a little expensive ($183 with shipping from Tischer) but to think what could have happened if the pin worked itself loose and into the engine.... Well, like I said, I saved money (and potentially the engine)




see above.

Apart from the rattling noise what other problems was you having?
reason why I ask is im having problems with mine and trying to find out what is wrong

Originally Posted by coupe*steve

Apart from the rattling noise what other problems was you having?
reason why I ask is im having problems with mine and trying to find out what is wrong

This thread is from three years ago. The OP hasn`t been around in a long time....

Hello guys.
I have an idle problem with my 325i E90. The bimmer has a poor start (it tends to die after it runs for 3-4 seconds) and at the last moment it revs up the engine to stop it from stalling. Another simptom is that the RPM needle starts to slightly fluctuate only after the car warms up. I looked for vacuum leaks(2 on the DISA valves) and sealed everything and did a diagnosys test. It reveiled a P160F code - "Power management problem" and P14C3 code - "DISA (Differentiated Intake Manifold) Actuator 2 Mechanical or Hardware Defect".
I looked at the 2 disas before when I was looking for vacuum leaks and besides really bad seals (which looked like they exploded) they looked fine.
Pictures of the 2 DISAs:
http://www.e90post.com/forums/showth...8#post11967898
Now this error code apeared.
Can a bad DISA influence the car's starting or the fluctuating in RPM at idle?