It's a bandaid not a cure. I wouldn't do it until I exhausted (pun intended) all other remedies. You might have enough of a stud left to grab and turn once the manifold is off. Tapping the wrench after a good soak works. YMMV
These are overexagerated statements:
Cost Savings
The traditional repair of removing the cylinder heads and manifolds and drilling the broken bolts out of the cylinder head can reach into the thousands of dollars. In our area, the costs can range from $1,200 to $3,000.
There is potential for additional damage to the cylinder heads if the traditional repair of drilling out the broken bolts is used. If the drill slips while drilling the bolt out of the cylinder head it could cause irreparable damage to the head, which means the heads would have to actually be replaced, resulting in more cost.
How about an estimate of a little time and effort alone?? Slipping? If you have to drill, it's not always the case, leaving the manifold on helps protect the head.
Permanent Fix
Even if the traditional fix is used and the broken bolts are removed and replaced; it still does not necessarily fix the problem. The factory bolts are too small and will continue to break again and again.
Our Exhaust Manifold Bolt Repair Kits are a permanent fix! The brackets will continue to prevent exhaust manifold leaks for the life of your vehicle.
This is a scare tactic. Bolts usually last the lifetime of the engine. Some anti-seize when they go back in helps a lot