hey yall, i have a 2001 super duty 6.8L and for a while now it has this whistle when I acdelerate during the first 10 miles or so but after that it goes away. It almost sounds like an exhaust manifold is leaking and when it heats up it closes the leak. I got underneath today to check if any of the studs were loose. The bottom rear bolt was very loose and when I tried to tighten it, it would just spin. My immediate though was that it snapped off in the block. I backed it out and it didn't seem to be broken. My next thought is that it is stripped. other than tapping it what can i do?

 

If you think it's stripped you could remove it, run a thread chaser into the hole to clean/clear whatever threads do remain, blow it out good with compressed air and install a new stud, trying to get it all the way bottomed out in the hole. You may get lucky and catch a few good remaining threads deep in the hole and it will pull up on the manifold and close the cold leak. Or just get used to the whistle.......

 

Might have to pull the manifold, if the threads are bad in the head I would put in a heli-coil and install a new stud. Might want to have the manifold surfaced. I have a broken stud in my 01 V10 but haven't tackled the job of fixing it yet.

 

Those were known for bad manifold bolts. Had the passenger side begin to leak on my 2000 about 2 years ago. Had Ford replace them.

 

Did Ford help you out, or was it all on you? If you paid for it about how much did they charge? Not real excited about tackling mine.

 

They are not known for bad manifold bolts until they get stressed. The head is one metal, the manifold is another, and the stud still another. The stud is the stress point and they need to be changed as you get into the higher mileages.

For trucks that go multiples of 100,000 miles, they are a consumable!

Of course, this all depends that what I think I have learned on this site is correct...

 

Truck was way out of warranty so it was all on me. Forget the price but go to Ford and get a quote. It wasn't cheap, but what is. It was fair for the work and time they got it done as I was not interested in tackling that job.

 

That sounds like a really neat idea. I don't know much about them though. Would I have to get a different bolt to fit in there and what size would I need? Thanks

 

I have had mine done twice before. The first time about 80,000 and the second at 160. I'm at 250,000 now and just want the whistle to go away.

 

I had the ford shop do it both times I've had it done up till now. Last time I had them done was over $600