Broken Exhaust manifold studs

Just a quick question. had my disco td5 xs for 4 days now. Traced a whistling (via google) to the common warped exhaust manifold. Contacted the garage I bought it from who assures me its no big deal as long as its not blowing on anything. The only broken studs I can see are the front 2 and a little bit of sooting from that area. The garage gave me a 3 month 3rd party warranty but stated it might be best to wait till 1 month from the end before taking it to my local garage to get it fixed (under this warranty) as they usually only pay for things that are broken. Is the whistling just an annoyance or does it do long term damage if you don't get it repaired?
Many thanks in advance for any comments.
Rob.

It is a big deal get it fixed at there expense. And don't take no for a answer, and I believe a exhaust leak is a failure

If they're broken then get them fixed, simple as that

Warranty covers it and its obviously broken if its warped

Many thanks. will pop to my local 2morrow.

Got a reply from the selling garage saying to return my disco for repair. Pleasantly shocked. Was expecting a problem. just goes to show im not as good a judge of character as I thought. Not looking forward to the 1 1/2 hour drive to drop it off and same when I pick it up though.