Vise grips were no good in my case. I'd like to also advise other from using a drill to remove the bolt; small m7 bits just ended up snapping, and the big ones getting dull. Hopefully angle grinder will do the trick.
In case anyone's interested:
With the exhaust manifold removed, I was able to remove the green and purple bolts (latter slightly loosened to make it pivot) pictured below, from under the vehicle. For the blue bolt, I had to remove air-intake hose. Also had to dismount the radiator(?) hose at the front of the engine, and disconnect fuel filter hose, to prevent them from getting damaged while lowering engine.
The passenger side mounts both need to be loosened, in order to bring the engine low enough to get a direct line of sight of the tensioner bolt.
I was able to use a 20v battery powered grinder to take off the head of the bolt in under 5 minutes, then use my hand and un-thread it.
I was able to also use 'cheap' HSS M2(?) left-handed drill bits to remove that AC compress tensioner bolt that has tendency to snap off.
2001 Integra GS Automatic Coupe; B18B1: 240,000 miles.
Last edited by k3ntegra; 04-09-2019 at 07:23 AM.