So I have seen several posts all over about GM broken TTY bolts. I have been an auto mechanic for 20 years, most as private fleet mechanic. This is the first time I have encountered this problem with head bolts. I took the head off of a 2006 4.2 L6 because of bad valves. I tried the hammer and punch, rattling the bolts with an air gun, tightening a bit then backing off, working the bolt back and forth, etc etc... nothing worked. I broke 11 out of the 14 bolts.
So here's how I removed them. You don't need a $400 extractor set.
I started by filling each bolt hole with PB Blaster penetrating oil for 2 days. Then I got a Blue Point E1020 extractor set ($125). It worked great on the one bolt I used it on. I used the centering sleeves that help center the drill bit on the bolt on every bolt. The sleeve keeps you from accidentally messing up the block. I had to put a single layer of electrical tape around the sleeve to make it tight in the hole in the block. But this set doesn't have left hand drill bits. Then I discovered that long left hand bits are hard to find. So I picked up a set at Harbor Freight for $9 (Item 61686). I figured they only need to last for a few drills anyways (but I used cutting oil, and the bit stayed very sharp for all 10 bolts). I also picked up a $10 screw extractor set(Item 95530). I used a cordless electric drill, the rear 4 bolts will require a right angle drill. The left handed bit caught and removed 8 bolts without using an extractor. The 2 very rear bolts required some help. I drilled the bolts with the 3/16 left hand bit, then used one of the HF screw removers with a 3/8 ratchet. The screw remover caught the bolt and spun it right out without having to drill very deep.
All the bolts came out clean. The holes look great, and I expect no stripping problems going back together. I hope this info helps someone out there. Good luck. Take it slow, lots of lubricant. And keep the holes clean of cuttings while trying to remove the bolt.
So here's how I removed them. You don't need a $400 extractor set.
I started by filling each bolt hole with PB Blaster penetrating oil for 2 days. Then I got a Blue Point E1020 extractor set ($125). It worked great on the one bolt I used it on. I used the centering sleeves that help center the drill bit on the bolt on every bolt. The sleeve keeps you from accidentally messing up the block. I had to put a single layer of electrical tape around the sleeve to make it tight in the hole in the block. But this set doesn't have left hand drill bits. Then I discovered that long left hand bits are hard to find. So I picked up a set at Harbor Freight for $9 (Item 61686). I figured they only need to last for a few drills anyways (but I used cutting oil, and the bit stayed very sharp for all 10 bolts). I also picked up a $10 screw extractor set(Item 95530). I used a cordless electric drill, the rear 4 bolts will require a right angle drill. The left handed bit caught and removed 8 bolts without using an extractor. The 2 very rear bolts required some help. I drilled the bolts with the 3/16 left hand bit, then used one of the HF screw removers with a 3/8 ratchet. The screw remover caught the bolt and spun it right out without having to drill very deep.
All the bolts came out clean. The holes look great, and I expect no stripping problems going back together. I hope this info helps someone out there. Good luck. Take it slow, lots of lubricant. And keep the holes clean of cuttings while trying to remove the bolt.
