awilli6

Hey guys,

I have a 87s4 nd I'm in th middle of trying to change the oil filler gasket and reach the hose connected to the oil housing. The hex bolt that goes into the thermostat housing has hollowed out (no sides for the Allen wrench to grab). How can I get this bolt out? I can't get vise grips on it. HELP

UncleMaz

Try Irwin brand bolt extractors. They have a thin wall socket that digs into the side of the allen head. Tap them on and ratchet off.

UncleMaz

I am pretty sure most national brand auto parts stores have them.

awilli6

Thanks, I'll give it a shot.very frustrated.

Bilal928S4

OR
Cut a slot on the head and see if you can use a screwdriver to take it off. Lots of penetrating oil, maybe a little heat to dislodge the frozen threads.
I have heard acetone & ATF is a great penetrant.

Kevin in Atlanta

+1 on the extractor - had to use mine on two seat allen head bolts. Nothing as satisfying as the sound of the crack as the bolt turns.

AirtekHVAC

Isnt there a socket called a gator grip? It has like a gazillion little needle like fingers in it, that conform to any bolt head you press it over, and then the more you turn to loosen, the harder it grips....in fact, I am sure I gave one somewhere...if I can find a link or pic, I'll post it.

AirtekHVAC

This might work....

aaddpp

I had the exact same problem on one of my water bridge bolts - center hex was stripped with nothing for the key to bite on. I tried notching it with a dremel, but I couldn't get enough force on the bolt before the flat edge screw driver I stuck in the notch would slip. An Irwin bolt extractor socket was ultimately what I used to extract the bolt, but...it wouldn't fit between the intake and water bridge, so I had to wait until I pulled the intake to remove the bolt - something to consider depending on which bolt is stuck.

Lizard928

Get a slightly larger torx bit and hammer it in.
Or just drill the head off and lift off the bridge, then remove the rest after.

Hilton

These are good too for socket-head bolts:

http://www.irwin.com/tools/screw-bol...-522532-series

GregBBRD

This is the way!

Colin is amazing. How he knows all this stuff, at his young age, speaks volumes about how smart he is.

Just get a drill bit slightly bigger than 8mm and use the stripped out hex area to keep the drill centered. Drill a little bit, until the head falls off. If you get down more than the thickness of the head and it has not fallen off, simply start "rocking" the drill motor side to side, back and forth, in a circle, until the head comes off. Lift the eentire assembly off and then deal with the "stud" that is left.

SeanR

Agreed with Colin and Greg.

I avoid 'extractors' since most of them break and then drilling out the bolt/hex head is just that much harder.

UncleMaz

The kind of extractor I am referring to is below. I have removed the exact bolts the OP is talking about as well as the rounded cam tower allens with the same. That said, I am sure what Colin, Greg and Sean use will always work.
http://www.irwin.com/tools/screw-bol...-extractor-set

brianrheffron

+1 on the extractors pictured above.
Wish I had had a set 30 years ago when I started working on classic cars.
These will do the job on any nut or bolt no matter how rusted or rounded.
I don't think they have ever failed to work for me.