I have been reading a lot about the V10 have bad exhaust manifold studs. Seems like a lot of people are finding them broken. I just bought from my dad his F250 SD 4X4 extended cab with a 107,000 on it. I had a 1998 F150 which had some broken studs on it. I think I'm starting to get the same sounds on my 250 now. Almost a cross between a tick and pressurized air on the drivers side. I looked at the studs and nuts, there rusted pretty bad, but all are there. There is a little discoloration on the drivers side head at the last or back outlet.? Seems to be a light greenish color just be the exhaust manifold. If this is the problem, how much stuff do I have to remove, and how hard is it to do? I have limited work experience with cars but have worked on them ( changing starters ) and are very good with hands on stuff.

I also have what others seem to have on a cold start a knocking sound that goes away after about 5 sec. or so. How worried should I be about that also?

Please help, Travis

 

Travis,

I feel your pain. Go down to the V10 subforum and search exhaust studs. You should get enough reading to keep you busy for awhile. It is a nasty job, not for the faint of heart. I have a lot of car repair experience and I didn't want to tackle mine when the time came. It cost me around $1,400 to have the repair done by a reputable shop. If you have lots of time for your truck to be laid up, you may want to attempt it, as this will take a non professional a few days drilling out studs and replacing them. Even if they are all there now, they will break as soon as you put a wrench on them, not all but enough of them to make your life miserable. If you have experience successfully drilling out broken studs and feel you can do it without breaking the easyout (you try first) then give it a try. You also have to careful not to drill too deep or off center and hit a waterjacket in the head. You will need a right angle drill. From what I've read the best way to attack this is to remove the inner fender plastic. Some have had success welding a nut onto the end of the broken stud and then backing the remaining stump out as long as it doesn't break below the surface of the head. You will want to take the manifolds to a machine shop and have the surface milled before putting them back on. Another factor to consider is how you will get the truck to the shop when you give up and decide to have someone else do the job. These were the reasons why I bit the bullet and paid someone else to bust their knuckles. Good luck.

 

Ugh, had to have that done last summer. I started it myself, and ultimately took it in to my mechanic to have them finish the job. It's just a bear to do, and they pulled the heads to do it properly. I have not had an issue since then. I did a couple of things differently than others do,however. I've been building and driving Porsches, Audis, and VWs for years, and they use the same size exhaust stud as the V10. I have used the studs and copper coated pinch nuts from Techtonics Tuning on my cars for ages, and have had not one failure....ever. Racing or street use. So that is what I gave the shop to use. I also tossed in some Ford Motorsport shorty headers and put in Remflex graphite gaskets, and so far they have lived up to the hype and stayed sealed. The headers have worked well, MUCH better than the logs Ford called manifolds. If you have those awful cast iron manifolds, might be a good time to upgrade since they'll be off anyway. However, if you want to know more about those studs and nuts, shoot me a PM and I'll give you a Techtonics part number.

 

I have never heard of the exhast studs breaking. That would suck repairing. But I could see it happening though. being in an aluminum head and a heavy cast manifold. Aluminum expandes when hot and contracts when it gets cold so I can see the studs breaking. Guess I better check mine! I have a 98 F350 V10 same v10 as the one you bbought. I do sometimes hear ticking sometimes when I first start it sometimes. And sometimes its not so much a tick but more of a light knocking. I am not sure what valve train is run in the v10. if it has the ajustable tips, they may just may need to be adjusted (re-lashed).

 

[COLOR=black][FONT=Verdana]Guys, I’ve got no idea now. I got a stethoscope from work and put some tubing on it. Stuck that to where I thought the noise was coming from and basically got nothing. Then I got some bigger tubing and put that to my ear and found something that sounded like what I hear while accelerating, just very faint. It's where the manifold and exhaust pipe come together. I don't know, I'm pulling my hair out, there is something that just does not sound right. I want to know that there is nothing wrong with it before I take it to the mechanic. Or vice versa. When you guys had your problems, was it obvious, or was it subtle? I’m lost.
Travis

 

I get some start-up noise as well, but it's piston slap, which the V10, at least early units, seem to be well known for. My 2000 Cherokee has it, and one of my Dad's Silverados did, too. Annoying, but that is about it.

I am sure there are several factors in broken studs, from expansion issues with aluminum heads, steel studs, and cast iron manifolds. One or two of mine looked like they were just poor quality steel, and one looked like it had been in a stream of exhaust gas leaking past the gasket, which when combined with expansion stress and maybe even just plain old thermal cycling caused it to fail.

The copper coated locking nuts I put on are pinched so that they lock on and stay put...as I said, never had a failure with the combination.

 

The exhaust leak was obvious...you could hear it best with the hood up, but it was apparent at all times, and sounded just like what it was. It was like valves way out of adjustment, but sharper because the sound was external, and it was isolated to #10, so it was more like just one valve out, not a bunch of them.

The piston slap is there primarily when the engine is cold...the piston being aluminum is a bit sloppy in the bore until it heats up, so the skirt has just enough clearance to rock back and forth a bit and "slap" the wall of the bore. It is annoying, but I've never had a problem with it in any car that had it. I've heard it in some engines at a level that would make me want to tear the engine down, but once the engine warms up a bit, it dies down either completely or to a level I just don't notice.

 

That noise could be a spark plug that is working loose and about to attempt an escape from your heads.

 

Now that is true too...take that 'scope and listen around the plugs to see if you can pick it up louder. The thing I don't like about forums is trying to decipher or define/describe a sound which might be perceived a bit differently be every one of us.

And honestly, I'd forgotten about the spark plug problem. With a bit of care, it's so easy to prevent it really should never happen.

What I have not asked is if the noise is always there, at the same intensity, or if it diminishes as the engine warms up. If it's always the same intensity, and coming from from the top of the engine, I'd shut'er down and do a plug change. It's annoying but not hard, and takes one more issue off the table.

If it goes away, could be something is expanding and sealing up, like a manifold, piston, etc.

 

Well the sound does change when giving it some gas while driving. At idel you can't really here it. Mainly only when your going. And it does seem to diminish a little when it warms up. It would be great if someone would tell me that a lose plug could seal up when the truck warms up. I have had a plug blow out on a VW dune buggy before. I don't remember if there was any signs that it was about to happen or not. Harbor Frieght has a electronic headset with a mic made to look for sounds coming from an engine. Think I might pick one of thoughs up and give it a try and then take it back. I hope I'm not wasting my time our anyone else's.

 

My exhaust manifold leaking did seal up as the engine warmed up. I could hear the ticking when I drove alongside a wall of a building or a concrete lane separator. The exhaust manifold leaking from broken studs is very well documented, just go to the V10 forum as I suggested earlier and do a search. What you are describing is very typical of leaking exhaust manifolds. Do check your plugs but I'm sure you are looking at a manifold stud repair. The V10s are a great motor. The 2 weak points are the manifold studs and the possible plug blowout issue from early V10s. For what it is worth, my '99 has just over 100K and has never spit a plug. I did have the leaky manifolds.

 

I've seen friends lose plugs on VW and Porsche heads before, and had to help the repair them, so I learned early how to treat aluminum cylinder heads. Too spendy not to.
If you are not sure it is NOT a lose plug, and, just to be on the safe side, I'd just do a plug change now. It really is not that hard if you take your time and use a bit of fuel line or heater hose to pull them and then start the threads on the new ones...there are some great write-ups here about the procedure, and it's a great comfort knowing you have anti-seize and the correct torque....just like on a VW.

The problem with IDing noises while underway, from my perspective, is all the noises that come with being underway. If we didn't have the spark plug issue, life would be easier, wouldn't it? But, once you have new plugs in, and know that it isn't them, the rest is easier.

You could put that stethoscope around the manifold studs and see if you hear anything more clearly.

But back to the plugs. As a bonus, when you have the coils off, you can check the boots and spring connectors. Or, better yet, pick some fresh ones up at Napa...cheap, easy, worth the time. I think I paid less than 2 bucks each for a boot and spring.

 

Well a spark plug would make a kind of (spitting noise for lack of words) the looser the plug, the louder it will be. or there could be a bad coil boot to the plug. It might be grounding out to the head. Highly unlikly, but had it happen before. Best thing to do is start at the simplest and work ur way up from there. If its a plug, unless the hole is stripped, the engine warming up wont make much diffrence in the sound intensity. I used to be a automotive machinist, and had many people bring there heads in to be ground flat and check all the plug holes and remove exhaust studs that had been broken.
But like I said eariler, start at whatever is the easiest to fix and if that doesnt fix it, move on. but it looks to me I would bet on the exaust stud being broken.

 

Have to agree with simplest first. It takes a bit of time, and a bit of patience, but the plugs and boots are right there on top, and it won't hurt the truck one bit to have them fresh.

While you are there you can check the connectors on the injectors as well- I had a lean run condition caused by two injector connectors that were loose enough to interrupt electricity, but not so loose you thought it would be an issue. I simply got out some 6" zip ties and tied each connector down...no more problem. Also had a misfire on cyl. 8 caused by corrosion on the spring connector. Neither of those issues caused any noise, though. But, when you sort out the common issues on top, diagnosis becomes a bit easier.

I really hope you don't have to fix threads.

 

The plugs more than likely need changing anyway if there is more than 50k miles on them. The ticking is more than likely an exhaust leak at the manifolds. Even if it looks like the nuts are still on they could still be broken and rusted fast to the manifold.