Super cool airbox cover screw "fix"

[Derek C.]

So, about a year ago, I bought myself a peppy little money pit. Maybe one day i'll tell the whole tale of this car, but suffice it to say it has had a storied past, most of which I know nothing about.

At any rate, I did some minor repairs but the car mostly sat until this summer when I decided to work on it. Among the (literally) hundreds of things this car needs, I decided I should take care of some basic maintenance items. One of these is the air filter, since I assumed without checking that it had been maintained as well as the rest of the card had (not).

So my Mahle LX71 comes in the mail (after being returned to Amazon without ever arriving because it was damaged in transit) and I tell my GF I'll be back in 5 minutes. I can almost hear her eyes rolling because she knows how it goes on this car. This task was to be no exception.

So I already know that i have 1 cracked pillar holding one of the cover screws in, and 1 screw missing. Oh, and the strap that goes to the turbo pipe is absent as well. That should make this a 4 minute job, right?

The screw in the cracked pillar comes out nicely. No problem there. The screw in the rear "left" (driver's left, not mechanics) of course falls behind the engine. Fortunately I had a magnetic sweeper, so i found it, and promptly dropped it into the engine bay, where all screws belong.

anyway, having retrieved that, I go on to the third screw. It's a bit rusty, but doesn't look that bad, so I attempt to remove it. It doesn't budge, so I twist a bit harder and feel the sickening thump of a captive nut spinning through its plastic imprisonment. Not to be deterred, I doused the f***er with about a gallon of deep creep and walked away for a few hours.

I came back to the job later, armed with a large screwdriver, an impact driver, and a sense of grim determination. I set about the task at first with the large screw driver, no luck there as the nut was slightly free to move about its pocket at this point. For some reason, I thought maybe the impact gun would have more luck. This did a fantastic job of completing the captive nut's interior renovation. It now has a much roomier abode and is free so spin to its heart's content.

Not to be deterred, I went and grabbed the biggest pair of vise grips I had, and clamped down on the plastic housing. Now the little bugger wasn't going anywhere. After about 30 minutes of clamping, spinning, reclamping etc... I finally got one last try with the big screwdriver, aaaand... SNAP. Off came the screw. Or at least the screw head. The rest of the screw remained stubbornly encased in the little captive nut.



At this point, the plastic is mangled by the vise grip treatment, so with a little additional prying, I was able to remove this diabolical little captive nut. Fortunately, though they look exotic the screw are a perfect match for an M6x1.0 in some standard length i had laying around. I used those in the other 3 holes, with some anti seize for good measure. Since I had completely mangled the hole, I was also able to fit a corresponding nut into it, but I had to figure out some way to secure it. I opted for a hose clamp, but the ones i had laying around were not a great fit, and I only had 1 that was small enough anyhow. Given that this was permanent, and i had 2 to fix, and I'd rather not have one more piece of sharp metal sticking out in the engine bay, I bought a set of ear clamps and pliers from Amazon.

Apparently when not cracked, the little towers must be right at 15.3 mm, because I could not for the life of me get that size on there, even though it was right at the edge. I used the next size up, and clamped the buggers on there, and whaddya know, it closed the crack in the cracked one, and I can tighten the one I mangled down pretty good and it doesn't move, so I think I have a pretty good fix here.

[soxnail]

Here is mine
Sox

[Derek C.]

Nice! Ive seen lots of 951s without the airbox to pipe strap so decided not to worry, but I too had considered using pipe/water heater strapping.

Why strap over the top? To you have broken tabs on the cover?

[soxnail]

No broken tabs, but the cover was not sealing along the edges real well. So the straps keep the whole thing down and tight.
Sox

[snbush67]

That is cool, but check this out;

Training wheels on my Porsche

[soxnail]

Ok looked....I guess I am slow, but could not see the connection to a 951 air filter box ??

[Derek C.]

Originally Posted by soxnail

Ok looked....I guess I am slow, but could not see the connection to a 951 air filter box ??

I think the connection is "innovative" solutions to problems with our cars :-) Mine seals quite well, I think if it didn't I'd consider weather stripping on the top side of the filter but your strapping is a good solution too.

[DannoXYZ]

Awesome repair! What do you think about filling hole with epoxy to fully capture your replacement nut?

As for intercooler-pipe clamp above airbox, it's to prevent pipe from pushing out of intercooler-hose with high-boost. With stock boost, you may not have to worry about that. But with increased boost, you'll be blowing that pipe out of intercooler easily. Also blowing hose off throttle-body was well.

[Derek C.]

Originally Posted by DannoXYZ

Awesome repair! What do you think about filling hole with epoxy to fully capture your replacement nut?

As for intercooler-pipe clamp above airbox, it's to prevent pipe from pushing out of intercooler-hose with high-boost. With stock boost, you may not have to worry about that. But with increased boost, you'll be blowing that pipe out of intercooler easily. Also blowing hose off throttle-body was well.

Good to know! I will be sure to repair it before I go down that road. I'm not going to increase boost much, likely just a Lindsey instant RWHP kit which I believe only increases boost at the bottom and top end, but keeps the factory 12 PSI limit unless you add a boost controller too.

Re: epoxy, I considered it, but I'd have to use a different nut to avoid epoxying the threads. I was also going to test the plastic to see if it is ABS, in which case I was thinking of using acetone ABS slurry to re-form everything back together (a 3d printing trick)

[911tracker85]

But with increased boost, you'll be blowing that pipe out of intercooler easily. Also blowing hose off throttle-body was well.

after building the car and running stock boost for a year, began raising it as I have a boost controller.

went up a couple pounds. blew that hose off at the turbo outlet.

fixed that, then raise the boost again a couple pounds. blew the hose off the ISV.

planning to top out boost at 15lb. I notice that having the stock turbo, the boost peaks between 4 - 5 k, then trails back down as revs increase. expected that, as I know to get high boost at high revs needs a bigger turbo. right now I like it as it is.

just finished an AC delete and in the process made sure all the hose connections were very tight. started to take a drive and it was blowing smoke. checked and found I had mixed the ISV hose and the one from the AOS catch tank. putting pressure in the block.

need to find the 'dumb mistakes' thread and post....

[soxnail]

Derek
Thanks, I just wanted to confirm that I had not missed anything in your link
Sox