Disa Valve - BMW Forum

Barriesza · 01-19-2005, 05:31 AM

I would like to know what the symptoms are when this valve is faulty, Can it be repaired or must it be replaced. The engine idle sometimes hunts but not always. There is also a rattling noise coming from the valve at times.

geewitchery · 03-30-2005, 04:22 PM

I have a 99' 318I with the same rattle you are referring to. I have investigated the DISA valve to the ends of the earth (internet) and have found some interesting details. The valve on the 318 should be closed (under vacuum) when at lower RPM and open at higher RPM to utilise the different length inlet manifold tubes. This maintains the best performance from the engine at high and low RPM. I am in Australia and here the valve costs $315.00 so I will be trying to repair the one I have. I have already had it out once to give it the once over but in about an hour I will do some real tests and let you know what I find.

PS: If you own a 318I M43 the part number of the valve is 11611438404
Cheers

geewitchery · 04-06-2005, 05:18 PM

The disa valve has an outer seal (inside the manifold) and a diaphragm inside the valve itself. The valve is constantly fed 12 volts during normal throttle operation and then open circuits on higher RPM and throttle opening. This deenergises the coil which stops the manifold vacuum from reaching the diaphragm. The butterfly then springs open.
I disconnected the electrics and manualy secured the butterfly in the closed position. This had no noticable effect on the cars performance. I then secured the butterfly in the open (high rpm) position and found a noticable drop in low end torque and fuel economy.
The strange thing is, the rattling noise is still there

. Not as loud or constant but still there. The noise seems to only be there when accelerating (under load / heavy vacuum), I will keep working on it and update the post when I have more info.

peterkulesza · 04-07-2005, 07:52 AM

is this the same system as on the 6 cylinder vanos motors?

geewitchery · 04-08-2005, 03:22 AM

peterkulesza, I am unsure if it is the same as the Vanos.
I did some more testing today and the valve is supposed to remain closed until the engine RPM hits 4100, it stays open until the RPM drops below 3200 (irrespective of throttle position).
Interesting but no closer to finding my rattle!!!!

storme · 04-09-2005, 05:40 AM

pictures??? got any????

i have a place in my engine bay that gives a rattle at start up,,,,like a valve just under the manifold.....but i have no idea what it is..so maybe some pictures from you would help me ???

geewitchery · 04-11-2005, 12:56 AM

Quote:

Originally posted by storme@Apr 9 2005, 08:40 PM
pictures??? got any????

i have a place in my engine bay that gives a rattle at start up,,,,like a valve just under the manifold.....but i have no idea what it is..so maybe some pictures from you would help me ???

[snapback]328973[/snapback]

I will nab some pics and post them tomorrow.

geewitchery · 04-11-2005, 01:37 AM

This is a photo looking at the engine bay from the front left (sitting in the car left) guard (fender). I hope this helps. On my 318 it is held on with three Torx screws and has a two pin Bosch plug on the very bottom.

storme · 04-11-2005, 01:51 PM

thx for the picture,,,,,now i know what it is that is rattling when i start my car

so i think i need to replace this disa valve....is it easy,,does it just undo????

and are they expensive???

your picture was great thx a lot

or could i just undo it pull it out and give it a clean???

geewitchery · 04-11-2005, 05:05 PM

As I noted in one of my earlier posts, after securing this valve in both positions manualy, I still get the rattle. Just not as loud.
The valve is simple to remove, but you can pretty much only remove and inspect it. You will require a Torx bit for the three screws and you need to remove the clip that retains the Bosch plug on the coil at the base.
NB: You may need to remove some of the inner guard covers just to provide enough room to withraw the valve from the manifold. This is easily achieved.
It is a sealed unit, therefore you cannot replace any of it's components. My valve had a worn butterfly linkage, this allowed the butterfly to be riggled in both positions. It also had a torn seal on the vacuum side, this allows the manifold vacuum to pull on the valve's main operating diaphragm.
The unit for my 318 with an M43 engine here in Australia costs $315.15 (Part No. 11611438404).
PS: I have cleaned and checked the PVC valve (this mounts directly above the Disa and a little toward the rear of the engine), this had no effect on the rattle.

I hope this helps you out. I will keep posting any news.

storme · 04-14-2005, 04:12 PM

1 last question...

does the dme need to be reset???

also i found out the price in the UK

its £240 fitted incl vat

geewitchery · 04-14-2005, 04:43 PM

I am sorry I do not know what you mean by DME?

The only thing I can tell you electrically is that my 99 318I does not detect a fault if the unit is unplugged.

storme · 04-15-2005, 01:12 PM

i meant the computer (ecu)

some other website are showing a problem with the disa valve being changed and affecting the computer....i think our 318's are ok,,it seems to affect the 330's