We recently found out our 06 Hummer was one of the ones affected with the bad cylinder head. GM and the Hummer Assistance people are not willing to help out with the $3500 cost to get this fixed and I recently lost my job of 7 years back in January so my husband is planning on trying to fix this problem himself and save us some money. Any suggestions opinions?? Anyone else go throught this and if so where did you purchase the actual cylinder head valve itself? Is this something that has to be ordered through the GM dealer only? Would appreciate any help. THanks

 

its a major job for a trained mechanic, complex,critical stuff.
ive done engine work b4,wouldnt want to do it. jfwiw,honest opinion

 

The problem with the Atlas family of engines were they are made of aluminum. Bolts are hard to remove and often brake off inside the engine. Kent-Moore make a removal tool if it happens to you
Info;
#05-06-01-026B: Information on Torque to Yield Bolt Breakage and Use of Bolt Extractor Tool Kit Part Number EN-47702 for Removing Broken Cylinder Head or Main Bearing Cap Bolts on Inline engine (Oct 21, 2008)


A Torque To Yield (TTY) bolt, like a cylinder head bolt or main bearing cap bolt, may break during repair procedures. Interaction between a TTY bolt and threads may cause the bolt to bind or break on removal.
Prior to removing the cylinder head or main cap bolts, perform the following procedure:
Using an appropriately sized punch and hammer, rap on the head of each bolt. The vibration produced by this procedure will assist in successful removal.
If a head bolt or main bolt breaks during engine disassembly, a broken bolt extractor kit (EN-47702) has been released to assist in removal of the remaining bolt segment. Many times the remaining bolt segment will back out easily with a pick tool or a reverse twist drill bit.
Bolt Replacement & Tightening

Important: Never reuse TTY main bearing or cylinder head bolts. Always make sure that the engine block threaded holes are clean and do not place oil or thread locker on the bolts.
Utilize a thread chase tool followed by cleaning with dry compressed air to insure threads are clean and dry prior to installation of new TTY bolts. Bolts that creak and snap while tightening will fail due to excessive torque caused by threads contaminated with debris, antifreeze or oil. Trace amounts of oil or antifreeze will cause this condition. In extreme cases the threads may need additional cleaning with a non-residue cleaner like a brake clean product followed by drying with clean & dry compressed air.
Bolt Extractor Tool Kit Part Number EN-47702


The bolt extractor kit EN-47702 provides the following components to assist in removal of the broken bolt segment:

1. One 5/32" reverse twist drill - part number EN-47702-6
2. One double-ended drill pilot insert - part number EN-47702-1 (ensures a straight drilling procedure)
3. Drill pilot inserts for larger diameter heads or main cap bolts - part number EN-47702-2 (ensure a straight drilling procedure)
4. Bolt extraction #3 EZ out - part number EN-47702-3 (after the drilling procedure)
5. Bottom tap (M11 X 2) - part number EN-47702-5 (for the head bolts to chase the threads after the completion of bolt removal)
6. Bottom tap (M10 X 1.5) - part number EN-47702-4 (for the main bolts to chase the threads after the completion of bolt removal)

 

id repeat.

its a major job for a trained mechanic, complex,critical stuff.
ive done engine work b4,wouldnt want to do it. jfwiw,honest opinion

i wouldnt trust the job to a dealer mech.

 

i just had my head done ( for the second time !! ), i did have a head bolt break off, just for FYI.... and still have a lifter noise , tapping, so its going back to the shop.

 

I have done many cylinder head swaps, not a hard job if you take it step-by-step excluding broken bolts this happens to the best techs. With it being a inline motor I think its a little simplier then doing a V8, i would allow 4-5-6 hours off and maybe 3-4-5 back on.

The problem is the cylinder head itself will need hardend exhaust seats installed and new valves, may also need the valve guides done, but I would get a estimate from a good machine shop before I would procede with the repairs to the exsiting head since you can get a complete revised head from GM for $900ish. You will also need the entire top end gasket set, coolant, oil & fileter and fresh spark plugs.

I just had mine done total bill was $3700, I would have done it myself but it was done under warranty

 

the problem is the valves sinking in the head..you can cheat if your good and remove some off the valve stem.but you better know what your doing,to my knowledge there is no hardened seat available.