Head bolt pops during torqueing
Thread Starter
Staging Lane
Joined: May 2009
Posts: 96
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Head bolt pops during torqueing It might be okay, but it got me really nervous about stripping a head bolt hole out. On the last two bolts I got a really loud poping sound that immediately didn't sound right. At first I tried torqueing it again (last pass at 70lb/ft) and it did it again. At first thought "did my torque wrench break"? I go get the other torque wrench and I got a loud popping again when the wrench tightens, but it's definitely not the click of the wrench. Is this what happens just before the hole strips out? I was pretty thorough about clean the bolt holes out. It may be just the way the bolt tightens up on aluminum. I don't know. This is the first aluminum block I've worked with and the engine has never had the heads off before.
I'm going to retry it again tonight and if it strips it strips. I will be forced to pull the head and put new threads in the block.
I'm going to retry it again tonight and if it strips it strips. I will be forced to pull the head and put new threads in the block.
Thread Starter
Staging Lane
Joined: May 2009
Posts: 96
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I hope I got all the cooland out as well. I used a compressor and kept blowing with spray nozzle back and forth until nothing came out anymore. There was only one hole that took a while to stop getting liquid out. Then I chased with a bolt ground flat on one side.
Does a block cracking make a pop and how can you tell it cracked? Is it internal or do you see something on the outside?
Does a block cracking make a pop and how can you tell it cracked? Is it internal or do you see something on the outside?
10 Second Club
Joined: Jan 2010
Posts: 195
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From: Houston Tx
I am not an expert, but we just did a heads cam install and the head bolt torquing was scary. You are using new bolts right? If you have not already done the final turns (stretch) on the bolts take them out and make sure the holes are free of water. Use a good wetvac to get it out. Are the bolts threading all of the way into the block without any trouble except for the last few degrees? I was for sure every bolt was going to break or strip out the threads, but we made it out all right. I used a torque spec, and then an additional 140 degrees or so. I don't remember exact #'s but check on LS1 How To for the correct info. Be sure to index the bolt heads that way you are sure they are to the right final degree. Good luck!
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Staging Lane
Joined: May 2009
Posts: 96
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I'm confused. Why would you worry about water in the jackets surrounding the cylinders if you cleaned the bolt holes out? They're not topped off after all the air blowing and running the top with a shop vac to get the head gasket material out of the cylinders, so the coolant kind of stays put.
The head bolt holes are blind and as long as you got out all the coolant you should be OK. If you are unsure then this remains an open question. Did you use the ARP Assembly Lube on the bolts? If not, you may have an inconsistent torque reading and this could be a reason that it is popping and the bolt is turning inconsistently.
Thread Starter
Staging Lane
Joined: May 2009
Posts: 96
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The heads are on and all bolts are in. I'm going to do another pass to recheck all the bolt torques.
No, I did not use the ARP lube. I did use a light moly grease, but not the ARP stuff. I would have waited, but I kind of got a little excited.
No, I did not use the ARP lube. I did use a light moly grease, but not the ARP stuff. I would have waited, but I kind of got a little excited.
That may be the source and you likely do not have a correctly preloaded bolt due to improper lubricant on the threads. Preload is critical on head bolts, you may want to re-consider continuing with the assembly until this is corrected.
I've had them make popping noise before, it's like the bolt is overcoming the resistance to move. If it was the block cracking mostly likely it would only do it once and not repeat when retorqueing.
On the 3rd pass there's a lot of resistance for the bolt to overcome before it moves.
On the 3rd pass there's a lot of resistance for the bolt to overcome before it moves.
I've had them make popping noise before, it's like the bolt is overcoming the resistance to move. If it was the block cracking mostly likely it would only do it once and not repeat when retorqueing.
On the 3rd pass there's a lot of resistance for the bolt to overcome before it moves.
On the 3rd pass there's a lot of resistance for the bolt to overcome before it moves.
The "pop" is normal. As long as the bolt/hole will hold torque, and the holes were properly cleaned out then you're fine. This pop happens a lot with ARP head bolts.
If your using stock bolts it could be the thread locker GM installs on the bolts sealing air under the threads and if torqued down too fast you can crack the block since the holes are blind and the aluminum below the bolt is thin.
Torque all the bolts down slow and that will usually do the trick but always clean out the block threads with a used factory bolt wire wheeled and cut long ways against the threads in 3 spots acting like a tap. You will be amazed at how much old thread sealer is still in there.
Thats what ive used for the past 10 years works like a charm.
Torque all the bolts down slow and that will usually do the trick but always clean out the block threads with a used factory bolt wire wheeled and cut long ways against the threads in 3 spots acting like a tap. You will be amazed at how much old thread sealer is still in there.
Thats what ive used for the past 10 years works like a charm.
Done 100 head swaps and 99 of them pop! Agree with the above statement, as long as holes are clean. Keep going you are fine, I have used motor oil on ARP bolts just follow the recomended Torque sequence.
Thread Starter
Staging Lane
Joined: May 2009
Posts: 96
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Thanks for all the replies guys, but it was me being stupid. The ARP bolt heads are 13mm. I was using a 14mm 6 point socket. It's weird I got that far and only three bolts were slipping. Not to mention only three of them got the socket stuck on the bolt head. I should have just been paying closer attention to what I was doing.
Tonight I hopped on top of the engine and torqued everything down and rechecked it. All seems good. Now on to check the pushrod length at preload.
Tonight I hopped on top of the engine and torqued everything down and rechecked it. All seems good. Now on to check the pushrod length at preload.
Teching In
Joined: Nov 2011
Posts: 11
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I know this is an old topic but im building a LS1 Aluminum block for a guy and I had this "pop" happen to me, only thing is the outside of the block had a hair line crack of which water seeped thru, tell me should I be worried or is this normal, I did blow the holes out with air, I guess on the other side I will use a wet vac, please help.