Engine noise and broken exhaust bolt (updated with pics)

Yes it will cause the noise. The reason it goes away is the metal both manifold and head heating up and expanding to fill the small gap between the metals.

A fix is the removal of the manifold and hopefully the bolt left the shaft extending beyond the manifold. If the bolt is exposed it makes removal much easier, If not then it has to be drilled out and either tapped or extracted. Not an easy job on the vehicle but sometimes can be done. If there is no room to work on the bolt to be extracted by drilling then the head has to be removed.

In either case unless you do it yourself, it won't be real cheap. Several hundred dollars to a grand is my guess at 120$ per hour depending on the solution to remove and replace the bolt.

An other point I forgot is the type of motor. Since you did not mention if you have a V10 or Diesel it will make a difference on fixing it. The V10 has aluminum heads and the diesel cast iron. Both has their pros and cons.

I had a 99 F53 V10 and 2 on the rear passenger side were broken and gone. When I went to remove the manifold 3 more broke off as soon as I tried pulling them. I fixed the passenger side by replacing all the studs in a SnowBird Park in AZ then drove it home and yanked the entire OEM exhaust and replaced it with a Banks system.

I now have a 2004 E450 at 32,000 miles and I am expecting the same BECAUSE we winter drive on salt roads to and from AZ twice a year.

Sorry, I know this rant does not help you other then to say "you are not alone".

super_camper wrote:
My Jayco class c is on a 2006 E450 with 60,000 miles. On the last two trips I noticed a new noise. It's really just louder engine noise and is linked with the engine RPM. Funny thing is it only occurs under load and only for the first few times a load is added after starting. After this time it's gone until the next start.

I pulled the doghouse to look at the exhaust and found that one bolt on the passengers side (2nd from the back) is missing, seems to have broken off. I've read about this problem with older Fords but not such much with the 2006 or later.

Now for my questions:
Would one missing bolt cause this type of noise?
Whats involved with repairing this? (It will go to a garage for the repair)

I've got one bolt missing also. It is what it is and it's going to stay that way. And no one bolt missing doesn't make that much noise like you describe.

Are you sure it's not just the fan clutch coming on?

The first time that thing came on when I was in traffic I thought the motor was going to blow up. No truck fan clutch sound comes even close to what that V10 fan clutch sounds like when it comes on, it IS LOUD!

Winter roads won't be the only issue. These bolts were junk from the factory.

rockhillmanor wrote:

super_camper wrote:
My Jayco class c is on a 2006 E450 with 60,000 miles. On the last two trips I noticed a new noise. It's really just louder engine noise and is linked with the engine RPM. Funny thing is it only occurs under load and only for the first few times a load is added after starting. After this time it's gone until the next start.

I pulled the doghouse to look at the exhaust and found that one bolt on the passengers side (2nd from the back) is missing, seems to have broken off. I've read about this problem with older Fords but not such much with the 2006 or later.

Now for my questions:
Would one missing bolt cause this type of noise?
Whats involved with repairing this? (It will go to a garage for the repair)

I've got one bolt missing also. It is what it is and it's going to stay that way. And no one bolt missing doesn't make that much noise like you describe.

Are you sure it's not just the fan clutch coming on?

The first time that thing came on when I was in traffic I thought the motor was going to blow up. No truck fan clutch sound comes even close to what that V10 fan clutch sounds like when it comes on, it IS LOUD!

Its definitely not the fan clutch, I put all of the 60,000 miles on this vehicle and the noise is new. It sounded exhaust related and that's why I checked the manifolds first.

It is a 6.8L V10 and the bolt is broken even with the manifold so if the manifold was removed there would be a stud.

Can the manifold be removed on the V10 without removing the head? It really looks tight around that area

If the bolt is broken off evenly with the outer edge of the manifold, you may not have to remove the manifold. Very careful drilling and an EZ-Out should remove the remaining portion of the bolt. The bolt is under no stress right now and should spin easily.

Experience doing this is helpful, but if what you describe is true, it's not a tough job.

Many Good Lucks,
Eric

Here are some pics of the broken bolt. The first pic just gives some perspective as it was shot from the passenger door. The second pic zooms in on the last two bolts showing the broken bolt in the second from back position. The third pic zooms in on the broken bolt and shows the stud still intact.

As you can see there is very little room for working on this? Can the stud be removed without removing the head?

Take it to a machine shop, not a mechanic.

Eric

can you get better access underneath ?? And maybe pull the tire off??

A friend repaired his in a class "A" while camping at Disney World. Used the procedure similar to what eric1514 described. He actually drilled them out and re-tapped the head then used new (larger) bolts.