Can the airbox be resealed? Best way?

[Tidybuoy]

My CIS is running 500% better now that I have got my pressures right. However, I still have a surging idle. I have replaced all seals, gaskets, hoses, etc... but have never tested the airbox. I've tried to check with propane but I have not had any success.

Anyway, one tiny screw on the airbox seems stripped. This is one of the screws that holds the top to the bottom. I recently acquired an airbox thru a purchase of spare parts and this airbox has a top section that is bad (broken oil breather connection) but the bottom seems perfect - this could replace my bottom section with the stripped screw.

When I separated the top from the bottom, I noticed that there isn't much sealing, just plastic to plastic and a groove. Would it be better to use some silicone on this before resealing the two halves? And, any good ideas for resealing the pop-off?

Thanks for any and all suggestions (except the ones that say: search is your friend )

[Flojo]

I reseald it with a black silicone and the screws.

For the popoff use a compound.

[Robey5]

Dad's 911SC - I am finishing rebuild (long)

There is a test procedure that I outline in page 9 and 10 of this, you can also test the air box with it in the car, but I found it a little misleading. The most effective method to test it is with it out of the car. I also pulled my box apart and re-sealed the seam with a 2 part epoxy. Good luck; I know how frustrating it is to deal with a leak.

[K Sykes]

Mine was leaking at that seam. I used JB Weld, applied sparingly, but thoroughly. Also cleaned the joint well. Clamped it overnight and it's been just fine. John Walker has a different adhesive he suggests, one that is more of a plastic adhesive.

I would not think that silicone is enough and silicone is unfriendly to O2 sensors.

[Flojo]

the silicone I used is special for to-dos on a car (e.g. to seal oil pans).

and as you only seal the plastic to plastic, I see no problem.

the biggest problem you get is, when one or two of the little brackets break off, those where the screws fix. then ypi lack the needed pressure on that spot to pinch the halves together.

[Tidybuoy]

Originally Posted by Flojo

Thanks, this is the exact area that I want to seal. And, while I'm in there, I might take a close look at the pop off to see if it is sealed well.

I will remove from the car and test the air box for leaks before doing anything. However, I know for a fact that at least one clamping screw is stripped (I don't see why they did not use nuts and bolts vs wood screws.

[Bob Kontak]

Originally Posted by Flojo

the silicone I used is special for to-dos on a car (e.g. to seal oil pans).

I did just do some research on the silicone based sealant and the main warning was not to use it on the crankcase, where a small amount of silicone could mix with the oil and via piston ring blow-by contaminate the O2 sensor.

I think the air box is different given it does not touch the oil. But I don't know for sure.

They (internet) talk of O2 safe silicone.

Tidybouy - just fill the hole with some JB weld and drill a pilot hole for the screw.

[Tidybuoy]

Originally Posted by Bob Kontak

Tidybouy - just fill the hole with some JB weld and drill a pilot hole for the screw.

The only reason I wasn't going to do it that way is because I have a spare bottom half air box (the section with the spider for cold start).

[manbridge 74]

Solvent welding is the only method I'd trust against the pressure pulse of backfiring.