DIY: Repair DISA rattle

ventsyv · Jun 3, 2009

If your engine sounds like a diesel your DISA might be the problem. The DISA is a valve that regulates the amount of air that goes in the intake manifold.
To diagnose the problem, simply check if the rattle is gone when the DISA is disconnected. First, open the hood and listen to the engine running. Now turn off the car, disconnect the DISA and start the car again. If the rattle is gone, you know the DISA is causing it.
http://s12.photobucket.com/albums/a2...t=MOV02505.flv

People have suggested taking the DISA off completely and closing the hole with metal plank. Others suggest cutting off the flapping part of the DISA so that it never closes. The third option is to either replace the DISA or try to clean it.

Parts: CRC Throttle Body Cleaner - about $10

Procedure: Take the DISA off.

Once you have it out, take out the little plastic cap. You see the moving mechanism for the rod. Spray Throttle body and clean it. See picture bellow.

Move the flap to fully closed position. Using the little straw that came with the cleaner, spray throttle body cleaner inside the the hole the rod goes into. (circle on picture) Keep moving the flap so that the cleaner can reach everywhere.
Spray and clean the flap area. (Arrow on picture)

Also spray in the little air hole. Be careful not to get cleaner in your eyes because moving the flap will expel it of the air hole.

Reinstall the DISA and the rattle should be gone.

Many thanks to Solidjake, Myfirst330Ci, Brian McKinney and all other bimmerfest members.

phlfly · Jun 3, 2009

Hey guys how is easy to remove DISA. I have read procedure, but is it easy to access there? how many hours?
Thanks

Solidjake · Jun 3, 2009

Try 15 minutes, lol. Remove the intake by taking out the 2 bolts and the 3 pop rivets, remove the MAF section, get a ratchet with an extension and a T40 (I think) head and just take out the 2 bolts. Slip it out and put it back in.

OP, thank you for this write up. :thumbup:

ventsyv · Jun 3, 2009

If you have T40 driver, it will take you 15 - 30 min. I took the air filter box out by removing the two screws, no need to take the plastic piece near the fan, just slide it out. You have to disconnect the sensors and undo the screw that secures the MAF sensor to the lower intake elbow first obviously. Then there are two screws that hold the intake elbow to the lower intake "hose".
Finally you have the two T40 screws. Just make sure you have T40 (star) driver. I tried using hex key for 45 min, then put everything back together, went to the store and bought a set of star keys. Using the T40 key I got the screws down in 2 minutes.

So to summarize:

2 screws - 8mm I think
3 flaw head screws
2 T40 screws

Nervous · Nov 30, 2010

Hey guys,

Thanks for DIY!
Quick question: the flap on my DISA moves freely for about 180 degrees. No resistance from stop to stop (from 0 to 180 deg). Is it how it should be?

marlin1881 · Nov 30, 2010

Nope. There should be spring-loaded resistance to fully close the flap, in one direction. If not, I'd replace the DISA assembly itself.

jcourcoul · Nov 30, 2010

I take it that since you have to remove the rubber air intake boots to get to the DISA and if they're old, cooked and brittle, there is a good chance of damage in the process, right? So it may be a good idea to have a replacement set on hand before starting, right?

Also, would a bad DISA or ICV cause failure to start?

mujjuman · Dec 1, 2010

jcourcoul said:
I take it that since you have to remove the rubber air intake boots to get to the DISA and if they're old, cooked and brittle, there is a good chance of damage in the process, right? So it may be a good idea to have a replacement set on hand before starting, right?

my guess is yes

Also, would a bad DISA or ICV cause failure to start?

my guess, no... unless there is a huge vacuum leak where the disa goes. but a vac leak doesnt seem to be your prob.... seems more like fuel pump related

bluebee · Jan 29, 2011

To those who already know their DISA is malfunctioning, you might want to look at this thread to see why you don't want parts of it flying through your engine and taking out cylinder #3!

jcourcoul · Jan 30, 2011

Good grief! :wow:

Betcha fixing that cost a wee bit more than a piddling new DISA!!

greghol · Jan 30, 2011

Yep, That is why I had the Indy replace the intake boot and DISA when they did the oil separator (CCV)!

Greg

Thawk143 · Oct 20, 2014

Hi. I have a E46 M43TU and cannot find any repair kits on the internet. The dealer quoted me $452 in South Africa to replace. The only post on this model I could find is a on E46Fanatics.com Anybody got any advise?

Brucifer325 · Oct 20, 2014

Google is your friend:

Pictures in thread are HUGE in case you have a slow internet connection.
http://forum.e46fanatics.com/showthread.php?p=12998212

Can't say for certain that this is the part you need, but it's not far off in price:
http://www.pelicanparts.com/catalog/SuperCat/0133/BMW_0133_FULINT_pg3.htm#item17

Thawk143 · Oct 20, 2014

Thanks, but with shipping cost I will probably pay the same as what BMW quoted me.

bluebee · Oct 20, 2014

- How to repair your DISA valve using titanium & aluminium machined parts and eliminate the chance of engine pin ingestion (1)

DIY: Repair DISA rattle

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