I'll post some pics later after I take them with my camera, but for right now I am having my morning coffee and watching the morning news.

I mentioned this awhile back. This past spring my 2CV seemed to develop a really bad exhaust leak all of a sudden. Turned out the air cleaner lid had popped off and was causing a horrendous intake noise.

The original air cleaner lid did not do this. When I got this car, the foam filter looked like it had swelled or stretched. So I bought a new lid and filter.

The new filter came with some sort of element with a piece of paper wrapped around it with small holes in it. Then the foam element wraps around it along with a black "clamp". So there was nothing wrong with the foam element, it was just missing the other filter and the black plastic clamp.

The new lid will not stay put. It seems something is conflicting or pushing against it.

So I compared the old lid (which gave me no issues) with the new lid.

This paper element seems to be the cause of the problem.

Yesterday I trimmed about 1" off the bottom the old foam element and a couple of inches off each end and applied some RTV on the edges and placed it in a bench vice to cure overnight. I've made allot of pre-filters to stretch over K&Ns like this. Once the RTV cures, I just remove it from the vice, cut off what had squeezed out and flip it inside out.

So I've modified the old foam element to just wrap around the center portion of the lid without the paper piece.

Any of you guys have this same problem? When everything is removed from both lids, they are both identical otherwise.

I'll take some photos and upload them later.

seems you have an old type filter element. For your car it is normally an foam element with an holed aluminium around it. The aluminum parts stay with the car and the foam can be washed in petrol and oiled or be renewed.

I wish I could post these photos as I go along. I'm going to have to resize these before I could upload them.

https://drive.google.com/drive/folders/ ... sp=sharing

Initially I took the old foam element and cut it down and siliconed the ends and turned it inside out.

But afterwards, It seems the three tabs on the lid are different between the old lid and the new lid. I transplanted the new element and foam filter to the old lid and it seems to fit the bottom housing better. I haven't drive the car to see if it stays put but I can tell it's nowhere near as hard to lock in place.

The new element looks like a piece of plastic with a plastic band with holes in it. It's not made of aluminum. Then the foam element wraps around it with the plastic clamp.

Yes i have seen those before too, but it might be they are for the metal airfilter housings with a plastic lid that is hold on by a winged nut. The plastic airfilter housings normally have the foam ones with an in and outside holed metal sheet

Not what I have seen fitted to later 2cv's, they have always been the type seen in Peppa's images. They will pop off when the three bayonet lugs are worn. Common cure is to drill the top in three places and insert self tapping screws to keep the plot under control.

That shown in AZL's image looks like the type fitted to Ami's. I have an older metal 'saucepan' lid aircleaner on the AZAM and the element is similar, but paper in a metal cage.

Also check the crankcase pressure.

You'll need a length of m6 threaded bar, three m6 washers, two m6 nuts and an m6 wingnut.
Drill a hole in the middle of the lid and a corresponding hole in the bottom of the filter box.
Two nuts and washers to secure the threaded bar at the bottom of the filter housing then another washer and the wingnut to hold the lid down.
Probably easier to understand if I had a photo but it's raining out there as usual (the glorious British summer).

Lenny,
that's how I've been doing them for many years, since self-tappers are a waste of time, however there's one more detail which I've added to prevent *inadvertent* overtightening of the wing nut from distorting, or even crushing, the lid.
Just a nyloc stop nut and a penny washer underneath the lid.

* There are more than a few numpties still on the loose, unfortunately...

AZL,
the filter element you've described is a (cheap) aftermarket replacement for the original item, which looked like this.
Perhaps it suited lazy garagistes, who couldn't be bothered with taking the few minutes required to disassemble the original parts and put them back together when cleaning a filter element or fitting a new one?

For turbofiat124,
the sponge is supposed to extend both above and below the two-part plastic cage which holds it in place.

Hi ken it's very possible. But i have got rid of the plastic airfilterbox now all together and put a metal one in. For the looks and to go with the single barrel carburetor.