One broken head bolt

[JustinM]

Just bought a long block from salvage in WI. Dealer claims to have run it prior to selling it. I trust that is true. Was cleaning it up a few days ago, pretty dirty for 208,000 m in addition to thick rust on the block. Was airing off some loose dirt and was stunned to see left side, second from back, head bolt spinning around like a windmill. Pulled the bolt out to see thick coat of carbon on the shaft and on the broken end which had a couple of threads remaining. Closer examination revealed slight small crack just above the break. I still kick self that this discovery happened three days out of warranty.

So now I am looking at a head job, unless someone here has a better solution. This engine appears to have no mods, beyond egr delete and turbo intake pipe. Overall, I am confident it is a good engine. Obviously, the engine had been running some time with this broken bolt, probably not too good though which leads me to wonder if owner decided to total the truck to collect. Being an old guy with very limited resources I have toyed with the idea of not having to pull the opposite head, but hate to think of going with the old bolts, can I replace with new bolts one at a time? Would love to do both, but like I said I'm old and tired; I've had a good deal of diy experience and understand that I have to fix this problem, I can't just throw several grand away cause I'm tired and can't afford professional help.

I am totally happy with the 242,000 m engine in my truck but it has a mysterious external coolant leak in the area of #3 injector and a description only estimate for repair at a performance shop clearly indicated far cheaper to just replace the engine, that is until this broken bolt expense showed up.

I put a wrench to the other 7 exposed head bolts and they were tight, so thinking all the rest are good. This broken bolt appears to be a stress break as opposed to somebody over torquing it, but who's to know.

Would greatly appreciate all comments from this great body of experts. JustinM in Tennessee

 

[2004LB7]

while its not normally recommended, many have replaced head bolts one at a time. usually when doing studs but should still work. while you have the engine out, might as well pull the head and remove that piece of bolt.

others will chime in to weigh in on the need to resurface the head. you should at least check it out with a straight edge and feeler gauge before bolting it back on

 

[ironmax]

More than likely that head gasket is toast where the broken bolt was. Your going to have to replace that gasket or your just throwing money away.

 

[JustinM]

Thanks so much for the quick replies and advice. For sure I know the one head has to come off to remove the broken bolt and the carbon on that bolt would indicate gasket leakage. Yes, will at least check the head with straight edge and gauge. If the head needs resurfaced, would both need the same? Does resurfacing require thicker gaskets?

If it turns out that I don't replace both gaskets, and replace just the bolts on the unaffected head, would each bolt, individually, be torqued back to full spec at point of installation?

 

[Bdsankey]

If it's got a broken bolt I'd venture to guess the gasket is toast like said above. Also being an LLY their OEM head gaskets have been known to fail. That said, head gasket kits are not all that bad price wise, where it can get really expensive is if you're paying labor AND the machine shop bill can get spendy depending on how many guides/seats need to be touched.

 

[Chevy1925]

given what you have told us about yourself and the engine, i would recommend doing both heads and gaskets. dont set yourself up for more headache down the road.

i would really inspect the block for any issues with that broke head bolt once you get that out. if thats cracked, that block is junk.

being 3 (now 4) days out of warranty, i would really call the dealer up and see what they will do.

 

[zakkb787]

Hands down do both. You literally just need two head gaskets and a bolt kit. Take both heads to have them decked and trued. That shouldn’t cost much. Have guides and seats checked and replace as needed. No reason to just do one especially with the block sitting outside of the truck. When reinstalling make sure you use the proper torque sequence. That is of course if you can’t get it warrantied. I would definitely try that route first.

edit: I would honestly do some more inspecting of your current engine. If you have an external coolant leak by your injector #3 (assuming you mean the second injector from the front in the passenger side as duramax are backwards) it could possibly be a blown head gasket spraying upwards as my truck just had the same thing happen behind the oil cooler or possible a cracked head. If it’s the second from the fronton the drivers side (which is actually #4) then you have the possibility of your coolant crossover tube being cracked as well as the two I just mentioned. As long as the issue is one of these things, I see no reason to put in another engine unknown to you that obviously already has issues. Try to diagnose where the coolant is coming from if you possibly can. Head gasket or crossover leak is a cheap enough fix. If the head is cracked, you have another head now that would need minimal work to swap over (deck it, seals, guides, gaskets, bolts). Also no matter what you do, I’d recommend changing the water pump while the engine is apart. Much easier to do now with the front cover off and halfway taken apart than in the truck 25k down the road.

 

[down_hiller]

I just did an LLY head job and it only cost me about $500. Machine shop charged me $140 to inspect, clean and surface the heads. If you have the time and take your time to do it right it isn't that hard.

 

[JustinM]

Wow! What great advice and information. So I am convinced to do both heads. I did call the dealer the day I found it, they were so sorry but said that I could probably get it fixed. Several factors involved, being too cold and wet here to work outside, I have no garage so engine has to be out and well covered. First day I was able to work on it I found the problem.

Good advice on the leaking engine [B]zakkb787[/B]. I have been thinking along those lines myself lately. The leak started a couple of years ago, hardly noticeable at first, but has grown to low reservoir message in about 40-50 miles. What put me off of that repair was the ridiculous (1) estimate to repair. The leak doesn't spray, it just weeps and now drips, it is the #3 inj. Engine runs fine with no codes.

Where can I find instructions on how to list the details about my truck below the message window like all you guys do. I have looked everywhere but still don't understand how.