I've had a broken exhaust bolt for a little while now front right of the engine. This winter, I have noticed a lot stronger exhaust smell in the cab. Looking today, the other bolt on the front port has broken now too.

So no more procrastinating. I'm going to order up some bolts, spacers and gaskets to do both sides and I'm looking for advice on removing the broken bolts. I do not have a welder, so I'm likely going to drill and extract.

I will remove the inner fender liner which should give me a clear view to the broken parts. I plan to remove the remaining bolts (hopefully not breaking any more) with a 3/8" impact with a 10mm socket. I suspect that the impact will actually benefit me by not breaking any more right?

Once the manifold is removed, a left hand drill bit and an extractor. I've never had good luck doing it this way, and am looking for the best advice to make this the easiest as possible. So if you've had to remove broken exhaust bolts, what worked for you?

 

What always worked for me was drilling and retapping.
Exhaust bolts usually are baked-in with corrosion and extractors will break on the try. Than you will have hard job.

 

All the parts are ordered. Questions remain though. Considering that there are already 2 broken bolts (and the use of penetrating oil) how best to remove the remaining 6 bolts? In looking around, a right angle drill, with a left hand bit to start the hole, then "gently" try an extractor. I've broken extractors before and have no intention of doing it with this one. Hopefully I'll just have the 2 to worry about, and if the extractor doesn't work, I'll keep drilling larger and try to chunk the bolt out. I've seen a quite a number of posts where the bolt comes right out, hopefully others have experienced this as well with the 6.0's?

 

Those bolts come out easy on newer engines that have not been used too hard, so take a close look at them. Left hand drill is good and I would say that if the bolt is not frozen in the hole, it will came out during drilling. Using extractor with torque wrench would not hurt anything, but as you experienced extracting broken extractor can turn into Hell.
I have good experience with PBlaster applied overnight.
Good luck.

 

Another great trick that beats all penetrating oils - heat up the bolt, a propane bottle torch will do on that size bolt, and once fairly hot melt a candle or straight paraffin wax on it. The wax pulls in like soldering a copper joint and works magic. On my father-in law's cummins I couldn't get the turbo downpipe bolts out with a 1/2" impact and after doing this they spun out with a 3/8" ratchet. That works second only to welding a nut on.

 

I've heard that before, I will give that a shot!

 

I just pulled both my manifolds off due to rear lower bolt broken both sides.
Definitely pull the inner fender.
My bolts were broken inside the block and I just drilled them and used a easy out (with heat)
They actually came out really easily...
good luck

 

Heat the remaining nuts with a torch, so you don't break any more bolts.

 

That's what I like to hear. When you removed the other bolts, did you have any additional breaking? Still debating the air tool method?

 

I would not use air.
I hit em with pb for a couple days and then they came out easy
I think they only go in at 26 or 28 ftlbs and they have some sort of antiseize on them from the factory.
I had one that seemed like it wanted to break so I hit it with a hammer a couple times and some more pb then I went on to the other bolts first.
Then it came out no problem.
The broken ones came out easy too... I could hardly believe it

 

I hope that I have similar results. Thank you, it helps!

 

Removing stuck bolts:

I find that heat can work if they are not already damaged too much.

Recently pulled some heavily damaged studs out of a pair of used LS7 cats. Applied silikroil 2x daily for 3 days and they came out relatively easy on day 3; broken/galled threads and all. Chased the threaded holes with a tap and good as new with new studs.

 

I couldn't get a regular drill bit to even touch the broken bolts on the rear exhaust port of my passenger head. I removed the manifold, which came off easy btw. I guess the heat hardened the bolts so a brand new cobalt MAC tool drill wouldn't touch it. I mentioned it to my boss and he said to use a masonry bit. I went to lowes and bought two masonry/concrete bits and the carbide tip drilled right through them. I used up one bit on each bolt but I was able to chisel out the remaining bolt "shell" and run a tap in the head to clean it up. I just used a regular grade 8.8 bolt from lowes with a washer and havent had any more problems in over 100,000 miles.

 

Guess this is too later but for someone else it may work. Drill
all the way through the bolt. Them heat it up and and spray in
the penetrating oil. Let it soak as long as you can before you
use the bolt extractor. This way you get oil on both sides. When
replacing you may want to use some good anti-seize on the threads.

Sean

 

I haven't started the process yet. I've got some carbide left handed drill bits so I think that I'll do some of all the above.....

Start with soaking the studs for a couple of days. Then remove the manifold, drill a hole in the stud using the left handed drills (hoping that those will work). Once drilled (hoping that it comes out while drilling ), heat up the stud and apply the wax and gently try an ex-out. I am not fond of ez-outs, and know full well how to be gentle with them. I'll keep up that process using larger bits until I get to the point I can pick it out. Hopefully, I'll drill center and straight!