Hey folks,
Im currently in the works of a vvt and dod delete in my 2013 Silverado with the LC9 5.3.
I had a bit of a moronic moment and forgot that the head bolt threads in the block are blind, and started to install the heads, without proper cleaning.

im trying to get the truck done and driving so I’m working on it after work tired, which is probably what lead to my negligence.

One of the larger bolts, underneath the pistons made a pop when I was just turning them in by hand, not torquing, just threading it in. However there was resistance which following the pop, got lighter and I’m panicking that I may have cracked the block, I then proceeded, to continue and torque the bolts to 22ft/lbs, the first step of proper torquing, but no further. I then went home and had a moment of realisation that I probably messed up while laying in bed.

My question is what are the odds I cracked the block, I did a visual inspection of the visible areas of the block and couldn’t see anything, but visibility is limited as the block is still in my truck. Any advice of other areas to check or any general guidance would be greatly appreciated.

my assumption is that it is most likely fine and I’m doubtful that me turning it in by hand would be able to crack the block but as stated I’m worried and am not near as experienced as some people on here, so I figured I should turn to the professionals.

Side note, this site has been a blessing for any questions I’ve had so far in the process, and everything has been going good up until this point.

Once again, any and all advice or knowledge you can provide is greatly appretiated

Thanks

 

If you were just turning it by hand, I doubt you cracked it.

The only way to be sure is to take the head off and inspect the holes/ threads.

 

i did remove the head and visually inspected it, seemed ok. I forgot to mention it is my first go at a large ls based project so I’m just in general nervous. I’m sourcing are borescope to look inside the threads to see if I can see anything, other than that I’m not sure what else I could do.

thanks for the insight

 

You are probably fine and got lucky you caught before final torque.. The pop you heard was probably trapped air/coolant escaping. Clean them extra good before continuing.

 

That’s reassuring, thanks for the help

 

Blow them out with compressed air and maybe run a nylon brush down them.

 

You definitely want to blow them out before ever inserting any bolt/stud.

 

Finger tight, and even 22 ft lb would not be enough to crack the block.... And definitely save completion for the weekend when you're well rested.

 

When I did the DOD delete on my L83 gen 5 engine, I blew all the coolant out with air then spray brake clean and blew that out as well. I heard a couple pops but I think it was more the threads skipping or jumping on the threads as they went in. Possibly some small amount of trapped air or coolant left like Dave mentioned. They all torqued down fine and I have had no issues since.

I have a GM mechanic friend who told me I cleaned mine more than the dealer does when they roll through for repair work. Since they are flat rate jobs the sooner you get them done the better off the dealer is. He said they hit them with compressed air once to get most of it out and then put new bolts in. Never cracked a block and never had one come back.

 

I always run a thread chaser down, spray with brake clean, blow out with air and then suction out with a small hose taped onto the shop vac. Corrosion and whatnot on the threads can't give an inaccurate torque reading..... Sounds like a little bit of overkill, but with the expense involved in these engines it's cheap insurance.

 

Just throwing this out there, and unless you are a machinist, I don't recommend it. We used a surface grinder with a cutoff wheel to grind a narrow slot on the thread Then ran a hardened nut onto the thread to deburr it. This allows air to escape so it didn't contaminate the helium in our helium leak test machines. Only had to go down to the minor diameter of the thread, so the fastener wasn't weakened. Best way is to blow out the holes with compressed air FIRST. FWIW....