There has been an ongoing debate about whether or not After Market Cold Air Intakes (CAIs) actually hav any benefit or gains over the stock CAI. One school of thought has been that the factory CAI is extremely efficient and is difficult to improve on and that the only gain would be a more aggressive intake growl. In line with this thinking, someone discovered (I don't know if it was kowached's idea originally) that you can delete the intake silencer and get the same results for the cost of a PVC cap and hose clamp. Substantially cheaper than an AM CAI.
Before doing this mod, please read this post:The following is the procedure for intake silencer removal on a 540i.
__________________________________________________ ___________________________Tools and Supplies__________________________________________________ __________________________________________________ _____
- 6mm socket or common screw driver
- 10mm socket
- 1 inch PVC cap (not plug, cap only)
- Hose Clamp
Time to completion__________________________________________________ ___________________________
- Approx. 15 minutes
__________________________________________________ __________________________________________________ ______
Make sure your ignition is off and remove the top engine cover.
Then, disconnect the mass air flow (MAF) sensor.
Disconnect the intake air temperature sensor.
I later discovered that all you have to do is press down on the wire clip with your thumb and slide the harness off.
Remove the air filter housing mounting fastener (10mm socket).
Loosen hose clamps (common screw driver or 6mm nut-driver).
Remove the air filter housing and MAF. Although unecessary, I found it was easier to work the housing out if I took the upper half of the housing off by disconnecting the clamps and exposing the lower portion of the housing containing the filter.
The red arrow points to the air silencer box.
Remove the air silencer box (10mm nut-driver).
(The following is extracted from Kowached's Camshaft Position Sensor replacement DIY on BMWTips.com.)
Replace the air silencer box with a 1 inch PVC cap (not plug, cap only) and a hose clamp:
Leave the air silencer box out and reinstall everything in reverse order of tear down.
Last edited by jamesdc4; 12-14-2010 at 08:28 PM.
awesome for that. Pinned it to my favs
hope you don't go through any puddles!!!
Also, unless you are missing the lower engine screen, it is almost impossible for water to splash up into the engine compartment.
Last edited by jamesdc4; 07-12-2009 at 06:01 PM.
nice little mod
what does this mod do??
Thanks man. I'll give it a try
I did this on my car, great mod.
Cave Creek, AZ
Tried this on my 2000, but the intake tube and silencer are one piece. No go.
EDIT: I cut the silencer off and fashioned a plug for the hole. I didn't really notice any difference in sound. It may make a difference on the earlier cars, but not on mine.
Last edited by ///Mink; 09-13-2009 at 07:30 PM.
I did this too, but then I put the silencer back. It made no difference at all. Also, intake silencer acts as an air pocket and helps the engine to breathe easier, according to a link someone else has posted:
Lazy Saturday drive in my E34: https://www.youtube.com/watch?v=TnzvZgPnOos
I just went through today the whole intake system, removed the "horne" inside the air box and followd the rest through the fenders to the front of the car and would have to say my 540i has an almost perfect intake system from the factory. It picks up the air at the front of the car close to the ground... perfect, just what a CAI is supposed to do. I left the intake silencer in the car for now, but definately can feel a bit better response once the horne was removed. By the way I also removed the nets on the 2 sides of the MAF and put in new Fram air filters while I was at it... big difference. Next mod is a fully ported Intake manifold and a ported throttle Body perhaps... also probably at the same time I will replace the injectors and the spark plugs...
Surprised nobody's mentioned that the E34 530i boot is the same part minus the hole for the silencer $25 from the usual places.
1994 540iT/6 - le swapzilla. 318k miles! DUDMD chip, M-Sport springs, Billy HD's, HID's, Sport seats, Poly bushings, other stuff.
1995 540iA M-Sport - 1 of 1 automatic AW3, 73k miles! Needs: front bumper cover, mem seat harness plug, US/euro ellipsoids. PM Me if you have what I need!
Both are always for sale.
Thats a great DIY......I was wondering, and this might be a stupid question so forgive me in advance. Can you do this if you already have an aftermarket CAI installed? Would it pose any issues?
Sure can, once I complete it I will definitly get some pics up. I hope it sounds better!
You can actually use a oil cap from one of one quart oil bottles too. It fits perfect, soo well that it stays in without a pipe clamp but id put a clamp on anyway.
Last edited by jhstealth; 02-01-2010 at 07:47 PM.
awesome mod ima do this tomorrow
Edit: just did the baffle delete on the intake, and the horn removal inside the filter housing
. I didnt notice a difference in the sound of the motor ie sucking sound
but my exhaust is pretty loud. But did notice instant throttle response in high rpms, and in low as well
I have proven results on the butt dyno
Also just did the idle control valve diy, and i think these 2 diy will compliment each other well
Last edited by Devo540; 02-02-2010 at 06:57 PM.
I believe the silencer acts as a shock absorber for air waves going through the intake. It is like adding a length of tubing above a water faucet so when you shut the water off the column of water in the extra length of tube acts as a shock absorber and you don't get 'banging' in your water pipes. Removing this piece eliminates your 'shock absorber' function and may cause the air to be more turbulent going through the MAF and into the intake manifold. I don't see why removing it would give you any improvements at all. Once it fills with air, the air probably just sits there to dampen air turbulence and even out the flow above since air is compressible.
A lot of these mods are in the 'eye' of the beholder. I agree that BMW probably was paying someone much smarter than me to figure out they needed this part. Maybe it is only a consumer satisfaction item for 'ride' quality and quietness, I am not sure.
Have a great ride in your BMW.
I've made this mod and there were no sound difference on my 02' 540i/6.