DISA Valve: what is this ?

[dnaiel]

Doing some general maintenance and got to the DISA valve and it was a bitch and a half to get off. Finally got it off and there seems to be some improvised gasket gunk all around the seal? I don?t know what I?m looking at. Wasn?t giving me any problems on that front so should I just throw it back on and run it?

[Oli77]

Is there tension on it? can you move the flap easily? I think that if the flap is easily turning, its toast.
It changes airflow distribution across the intake to improve performance. I am not sure what I am saying is correct. Someone correct me please.
The DISA is also known to break (the pin breaks) and it implodes into the intake and that is a very bad thing.
Hope the info I am giving you helpful. Should be plenty of youtube videos to check the function of it and what the symptoms of a bad DISA.

[Galapolis]

If it hasn't been replaced, replace it. I removed mine to inspect it, it looked almost like new and worked perfectly, so I put it back in. A year later, the flap broke off...