M5 airbox to plenum/tube fit issues

pas · Post by **pas** » Nov 10, 2012 2:14 PM

Working on changing out my air filter and removed the air box on my M5, but before I did, I noticed the very poor fit between the plenum/tube from behind the left headlight to the hole in the airbox. See pics at

http://www.flickr.com/photos/89905286@N ... 172739453/

I can't see any easy way to adjust anything that would make the tube seat properly in the inlet. I also understand that the foam gasket (falling apart on mine) is the same as that on the E30 and that part is still available.

Any hints or comments to fix this in an elegant way or reasonable manner?

Also, has anyone ever made a plastic replacement for the roughly 8lb or so large metal air box?

TIA[/url]

Mab1957 · Post by **Mab1957** » Nov 10, 2012 6:19 PM

The donut or washer-gasket is available from Blunttech.com. PN 13711312695 It will cover that gap.

There are a few discussions about the M5 airbox on this forum. Give it a search. Your research will reveal that others have determined the guys in white coats in Bavaria built a box that maximized the airflow. After market systems don't help a whit. The airbox and those pieces are very hard to find. If you do decide to go another way do not discard them. Pull it off, prepare the surfaces and apply a coat of paint to it. You might even find a reproduction of the sticker with a bit of research.

Where are you located? I'm in No. VA.

pas · Post by **pas** » Nov 10, 2012 6:26 PM

Thanks.

I'll leave it stock; it is just the fact that it has so much mass for an airbox and it is hanging out up front. Different era and I actually appreciate the sheer solidity of the approach.

I'm in the Frederick, MD area.

thanks

pas

Mab1957 · Post by **Mab1957** » Nov 10, 2012 6:41 PM

Good deal. There are some nice roads up there. Perhaps I'll see you on a drive someday.

Matt

pas · Post by **pas** » Nov 11, 2012 9:22 PM

Yep. Roads north up towards Gettysburg and Mount St. Mary's are great.

Are you sure about the PN (PN 13711312695) - it isn't showing up at blunttech or realoem.

About 10 years ago I was looking at an M5 and had it tech inspected by the guys at Intersport in McClean, VA. They had a BMW master tech even though Intersport is a Porsche specialty shop - really good work (I'm a card carrying PCA member for various reasons including the E500 I used to own). Didn't buy that one since it had two cylinders down from the others on the leakdown test.

pas

M5BB · Post by **M5BB** » Nov 12, 2012 3:06 PM

IIRC there is a "foot" on the bottom of the airbox that has to fit in the proper place or the box will not go down far enough.
Also check the plastic cover that the intake of the airbox matches up to so it is in the proper position? I should have a locating pin that twist locks into place.
HTH
Gary

Mab1957 · Post by **Mab1957** » Nov 12, 2012 7:11 PM

pas wrote:Yep. Roads north up towards Gettysburg and Mount St. Mary's are great.

Are you sure about the PN (PN 13711312695) - it isn't showing up at blunttech or realoem.

About 10 years ago I was looking at an M5 and had it tech inspected by the guys at Intersport in McClean, VA. They had a BMW master tech even though Intersport is a Porsche specialty shop - really good work (I'm a card carrying PCA member for various reasons including the E500 I used to own). Didn't buy that one since it had two cylinders down from the others on the leakdown test.

pas

Hmmm, I have two in a bag fresh from Steve at Blunttech. I pulled that # off the bag. I'll check my order to Blunttech and see if there was a different RealOEM number used. I'm not at home now so can't confirm.

Good points by Gary ^^ here. There is a positioning "foot" that could hold the box up/inboard if not in its shoe.

pas · Post by **pas** » Nov 13, 2012 12:10 AM

Thanks, Gary. It appeared properly seated on the rubber buffer though I'll check it more carefully when I reinstall it.

The plastic thumbscrew for the intake piece connection to the headlight frame is positioned correctly.

Karl Grau · Post by **Karl Grau** » Jun 04, 2013 9:04 PM

I got tired of the sorry state of my foam doughnut. It never sealed correctly and was always getting mangled. I tried to use double sided tape to make a better seal but I still always ended up with warm air coming in around all the gaps.

I bought some foam pipe insulation that is the same stuff as the factory foam (had to buy six feet though). So I cut a test piece which turned out to be a little wide but I tweaked it a little and now I FINALLY have a good seal.

The OEM ring.

Bulk

Test piece, looks just like the stock material.

ahab · Post by **ahab** » Jun 04, 2013 9:22 PM

Karl Grau wrote:

Dude, are those JVC GB-1E speakers in that photo?

Karl Grau · Post by **Karl Grau** » Jun 04, 2013 9:24 PM

ahab wrote: Dude, are those JVC GB-1E speakers in that photo?

You have an eye for detail

.

1st 5er · Post by **1st 5er** » Jun 04, 2013 9:44 PM

Karl Grau wrote:
ahab wrote: Dude, are those JVC GB-1E speakers in that photo?
You have an eye for detail .

All I see are couple of drunk flamingos.

Karl Grau · Post by **Karl Grau** » Jun 04, 2013 9:49 PM

1st 5er wrote:All I see are couple of drunk flamingos.

Well, obviously you don't have an eye for detail.

(and the flamingos are just napping)

1st 5er · Post by **1st 5er** » Jun 05, 2013 1:28 AM

I know what the next purchase with my Home Depot gift card will be.
That is unless you're willing to turn your purchase into a group buy.

To make it easy, what's the ID of that piece?

igotbank · Post by **igotbank** » Jun 05, 2013 9:20 AM

Karl,

I would've never thought to have used that. Which diameter did you get. I'm at work and will be making a Home Depot run after lunch today. I love this forum! Thanks and Happy motoring.

Karl Grau · Post by **Karl Grau** » Jun 05, 2013 10:21 AM

The ID is 3-1/8 and it was $12.46 for 6' at McMaster-Carr. I don't think Home Depot carries anything that large but I could be wrong. Mcmaster-Carr ships it it a long box with a cardboard tube in the center. shipping was $17.00 but that was with a bunch of other stuff.

I'd be happy to send a piece to anyone that wants one for shipping cost. I figure a 6"- 8" piece would be enough for a lifetime of doughnuts.

If anyone wants to buy from McMaster, it's item #4463K145
Ultra-Flexible Foam Rubber Pipe Insulation
.

1st 5er · Post by **1st 5er** » Jun 05, 2013 1:21 PM

PM incoming.

ahab · Post by **ahab** » Jun 05, 2013 3:21 PM

PMing

1st 5er · Post by **1st 5er** » Jun 05, 2013 9:19 PM

PP sent.

Karl Grau · Post by **Karl Grau** » Jun 05, 2013 9:36 PM

Sherman & Aaron,
Your packages will go out tomorrow. Thanks for the overpayments, beer will bought and drunk (drank?:?) in your honor.

ahab · Post by **ahab** » Jun 06, 2013 1:38 PM

Thanks for blazing the trail!

1st 5er · Post by **1st 5er** » Jun 06, 2013 10:41 PM

Karl Grau wrote:Sherman & Aaron,
Your packages will go out tomorrow. Thanks for the overpayments, beer will bought and drunk (drank?:?) in your honor.

Headed to the store...

igotbank · Post by **igotbank** » Jun 08, 2013 8:45 AM

You're right again Home Depot didn't have it. Pm coming

1st 5er · Post by **1st 5er** » Jun 08, 2013 5:31 PM

Got my box today. Pleasantly surprised; Christmas in June.

Chas, you shouldn't have...

Karl Grau · Post by **Karl Grau** » Jun 09, 2013 8:20 PM

I haven't heard anything more from igotbank so it looks like I may have one piece left (i'll give him until tomorrow in case he's having a wild weekend). All other pieces have shipped or will go out tomorrow. I hope it's all you dreamed it would be and more.

Karl Grau · Post by **Karl Grau** » Jun 10, 2013 5:34 PM

Sorry, but all the foam is gone guys. The last box will go out tomorrow.

TurboChris · Post by **TurboChris** » Jun 12, 2013 1:35 AM

Got a box today, thanks Charles!

johne · Post by **johne** » Jun 13, 2013 8:26 PM

Received shipment today. Thanks John

Karl Grau · Post by **Karl Grau** » Jun 17, 2013 5:41 PM

So has anyone come up with a good way to make a nice clean cut with this foam? I was thinking of trying the paper cutter at work but otherwise, I got nuttin.

tn535i · Post by **tn535i** » Jun 17, 2013 5:57 PM

If you have access to a lathe you'd be golden. Slip the foam over some kind of mandrel like maybe an aerosol can the right diameter, spin it in the lathe and slowly merge a razor knife held steady and it will sink down in perfectly clean. Move over and repeat to make several from one log of foam.

Otherwise maybe try the same approach with the can on a flat surface and a razor blade on a block of wood held steady above the surface and rotate the can up against the blade. Adjust the height of the wood block and make next cut.

The key in each is to have the blade true and square so it cuts in the circumference without wandering of course.

I've used this technique to cut larger diameter (up to about 3-4") things nice and square many times (provided it's not to long) and it is basically how they make lathe cut gaskets you see on the end of spin on filters.

Karl Grau · Post by **Karl Grau** » Jun 17, 2013 10:41 PM

I don't have a lathe but I like the way you think.

So I going to put this hole saw over a plastic handi-wipe container and then put it on the drill press.

I'll slide the foam over the the handi-wipe cylinder and then use a razor blade on the drill table to make the cuts square.
It's just wacky enough that it might work.

ahab · Post by **ahab** » Jun 18, 2013 9:44 AM

I haven't cut mine yet but I have some kind of a scraper that takes 4" razor blades. They're available as packs of replacement blades from Lowes et al. I planned to try that.

Or there's always one of these...!

gray635 · Post by **gray635** » Jul 04, 2021 9:02 PM

I'm resurrecting this old thread. The foam rubber "donut" on this M5 I just bought is in sad shape. I remember ordering one using the e30 M3 part number years ago, but can't locate that now on RealOEM. The part # listed in this thread above is not correct.

Does anyone have the correct e30 M3 part number for this thing? If so, please let me know. Otherwise, I'll try to create something out of a pool noodle!!

gray635 · Post by **gray635** » Jul 12, 2021 8:40 PM

Just found the current M3 part number for the foam rubber seal. Here is it for others who may be looking: PN 13 71 1 312 595

MyE28.com

MyE28.com

M5 airbox to plenum/tube fit issues

M5 airbox to plenum/tube fit issues

Re: M5 airbox to plenum/tube fit issues

Re: M5 airbox to plenum/tube fit issues