The mechanic says that maybe the cylinder head is too soft and that is why it is leaking. If it was new "genuine GM" are they not required to meet a standard. He suggested torquing the head a bit more maybe 20-30 degrees and hope it works. He said that the car should start now because the coolant would have drained down to the oil.

The mechanic suggests tightening head gasket bolts a bit more to stop the leak. Has anyone done this and can it work. If there is 25% chance it works then I should try it as it will not cost me any more...he will do this for no charge. Is it common for the block to need machining if the engine did not overheat. Although the head is completely flat, the block was not machined.

You have possibly the worst mechanic in the world. That guy should not be allowed to work on a bicycle let alone a car.
TTY should never be reused or re-torqued. It takes less than 5 minutes to check a head and deck for straightness.

​​​​​​​Careless? Let'* try dangerous. And damaging.

Same way it has been this whole time. I've never heard that this "mechanic" got the head put on right.

No need chasing why it would get in through somewhere we are guessing it got in, especially with this "mechanic'*" history of installing the head gasket terribly wrong. It has been getting in there. It is likely still getting in there.

You bought these within the last few days? . . . or are these the old ones from weeks or months ago?

Sounds right.

Why assume this? He has not gotten it right ever before, and if I remember right, he blamed previous torqueing issues on his new wrench that [must be improperly adjusted] or somesuch. It'* not rocket surgery to check calibration on a torque wrench, and since this mechanic claims to be knowledgeable, he should have either checked the wrench and/or known by feel that he was grossly over-torqueing and/or under-torqueing bolts.

Why? Is he not confident in his work? . . . or his wrench? . . . or the procedure? More isn't necessarily better.

Makes sense that it is a little more full after being warmed up. Also makes sense that this combination of abused head, stretched threads in the block, and who knows how many other defects, would combine for surprise results when you use the car. Could very well be that the head gasket had uneven pressure all around, and after shutting off, there was no more cylinder pressure while there was coolant pressure, and that combination finished off the new head gasket.

Those are pretty wide temperature swings, between 5 and ~100 degrees Celsius. That could have contributed.

Why were the head bolts lubricated? carfixer007 and I both advised this is the wrong way to do it. Now I am positive that the "mechanic" didn't torque the head down properly.

Yes, once again you are trying to start a hydrolocked engine.

Maybe, if the starter isn't ruined. You did bypass the fuse that was put there to protect various parts including the starter.

If the problem is electrical, it is probably a failed starter. If it is a failed starter, it was caused by trying to start a hydrolocked engine, and then trying some more with the fuse bypassed. The fix then would be to fix the engine and replace the starter.

It is likely that the head is warped because he tightened with oiled threads, and then overtightened while he was at it. A warped head will not seal well. Your current symptoms tell me that the head gasket is not sealing well. He has ruined your engine both again and more.

Oiled threads reduce friction while being torqued, the friction of the threads is lower. To get the same torque reading on the torque wrench, the head bolt has to compress the head much tighter than if it were done properly. Now you have pinch points under all of the bolts and lift points between the bolts. Make a ham sandwich, wheat or white bread, your choice. Cut it in half. Now hold a half up like you're going to eat it. The top bread is the head, the ham is the gasket, and the bottom bread is the block. Pinch the sandwich on each end. See what the bread does in the center? Same thing is what the "mechanic" did with your head gasket.

This part works fine on every other engine. The "mechanic" is wrong.

. . . or the "mechanic" is right: The head is too soft for his methods of overtightening until things break over and over and over and over and over and over and over and over and over and over.

Yes, they are. The "mechanic" has ruined it by installing it improperly. GM can not design to this "mechanic'*" level of ineptitude.

Should a standard Freightliner 80,000-pound GCVWR truck meet a standard? Yes, until you load it up to 200,000 pounds, bend stuff, then load it to 250,000 pounds and bend more stuff. Is Freightliner responsible for this? No.

So, it is grossly overtorqued, and his advice, as always, is torque it down even more? This is the definition of insanity. We've already been through this.

Sure, start it if you can. Coolant in the oil will finish this poor engine off and you'll finally have to go get a good used junkyard engine like we suggested months ago.

The "mechanic" is wrong. This is a bad idea. We've already been here and done this. Insanity.

We've already discussed this. These are torque-to-yield bolts. They can not do this properly.

No it can not work.

There is not a 25% chance this will work. There is a 0% chance it will work. You've already been through this with this "mechanic". It will cost you more.

No. It is not common. And with an overhead cam engine, you can't go machining it ***** nilly.