Radiator bracket/impossible screw

Hi all, I have a terribly rusted radiator bracket ( part9 99650415600) that i am trying to replace on my 2004 turbo. I am coming up against this final screw that wont move and would appreciate any tips. I think the bracket backs onto a plastic part here which might affect some solutions. I am also wondering if its a security torx and not a regular torx. P.s. its been soaked in pbb with no change. Many thanks in advance for any help Regards Karl

That will be a normal Torx and either T25 or T30 .. these often round out im afraid .. very common on undertrays and i either have to drill it out or i use a finger sander which is a sanding belt on a " gun " to wear it down . Use a small screwdriver to scrap away the inside of the Torx to get the best possible grip then pray .. sorry ... there is no easy answer on things like this .

Make sure you drive the socket right in, often the rust stops it going right home and makes rounding off inevitable. Also the shock from banging the socket in often helps. Try a good 1/4 drive first then a 3/8 and use a hand ratchet first rather than gunning them out. Rusted fasteners are so annoying!!

Thanks for the help both. Seems things start with cleaning it up a bit to get better traction. What do you think on using a product before screwdriver/wire brush/hammering in the socket. Something like bilt deox gel: https://bilthamber.com/product/deox-gel/ Also any favoured penetrating oils...i have pb blaster (this doesnt seem to have done much) and plus gas (arriving tomorrow). Do screwextractor bits have much success here? https://www.amazon.co.uk/Bosch-BSPE6D-12-Piece-Spiral-Extractor/dp/B07G1M1TQG Finally demort...where you mention drilling/finger sander...is this when you have to give up and basically destroy it? Would a dremel work here too? Thanks again for all the help Regards, Karl

Basically you need to scrape out as much rust as possible to get the torx fixing to penetrate as far into the screw as possible .. a small screwdriver or a pick .. an additive .. i can't say but i wouldn't waste my time on that to be honest . Lube has never worked for me but no harm in trying . If when trying to undo it just rounds out .. then we cut it .. a dremel .. finger sander which is what i use or a drill .. either way you are trying to cut the head off the screw .. cut the center and the washer part will come off .. after that you can often undo the remaining screw by hand or with pliers .. If not then lever the entire clip off with a screwdriver . Yes you will be replacing it with something .. correct items or a nut / bolt and washers . 997 undertrays have the best part of 30 of these .. i can " burn " off many to get an undertray off .. to the point i will sometimes ask in the office if i should do this .. We take undertrays off as part of a Major service .. it's not something that needs to be done but if the fixings are this corroded then i get permission first as each fixing adds up !!! EDIT .. don't bother with the amazon kit .. of no use here .

I have had success in the past with using a very abrasive paste in badly corroded fixings, i was first introduced to this by one of the engineers i work with. It provides extra friction to whatever driver you are using...... https://www.amazon.co.uk/Liqui-Moly...62&hvtargid=pla-349016040170&psc=1&th=1&psc=1 ..... every little helps!

Lots of help above. All I can really add is to suggest cutting a slot in the head and trying to use a screw driver, or nicking the edge and trying to knock it round using a hammer and chisel (or all purpose screw driver). What you need to do is break the corrosion between the screw and (presumably) the speed nut it's screwed in to. Ironically these can be more trouble than screws into a steel component because the speed nut moves around a bit and 'damps" your attempts to break the screw free. Soaking with penetrant is worthwhile. I use Plusgas, but you need to get it on the threads behind the plastic. Can you attack from the other side? My last resort would be drilling it out. You can then remove the component and sort the rest out on the bench. One last thing, as you try to undo the screw, put at least as much effort into pushing the bit into the head of the screw as you do trying to turn it. You may find as it starts to turn the threads strip and it doesn't withdraw. If this happens, wedge something between the screw and what it's screwed into and lever it out whilst turning to get the threads to engage. Oh and plenty of good luck!