Exhaust Whistle???

[JReichenbach]

Hey guys, my '05 3500 truck developed a whistle. Recently made a 2500 mile trip with 2 cars in the trailer. Wind was blowing and I was pushing truck pretty hard. About 1/3 of the way thru the trip, the noise appeared. Truck has 170,000 miles, Edge tuner on Tow, bigger injectors, and a Banks intercooler. Upon closer inspection, I see soot between #2 and #3 exhaust ports, hoses and clamps on intake side all look good, noise never got any worse last 1700 miles of trip. Am thinking about pulling exhaust manifold off, just wondering if I should just get a new manifold before starting this project. I would appreciate your thoughts on what way to approach this job, new manifold necessary, specific gaskets better than others, studs vs bolts, is the BD manifold worth the money, Dorman a viable option, etc. Appreciate the input, Thanks, Jim.

 

[Darkbloodmon]

If you've got soot at the ports then you've got a tell tale sign of a manifold leak. 170K miles isn't alot "relatively" for heat cycles. I would recommend just replacing the manifold gaskets with MLS and studding it if you're concerned about it.

I studded my manifold and installed new gaskets when I got my spent factory turbo blueprinted and installed lower mileage factory manifold that I had ceramic coated. Here is a link to the studs I used for my manifold. The Fleece studs are stupid expensive for whatever reason beyond me. Studs I used were stainless steel all the same.

Not much of a project unless you want to make it one, I really don't recommend Dorman hardware and products for the most part. Be a bit more specific as to which Dorman product you're talking about.

Installing the gaskets is a bit of a pain with the factory bolts and heat shield. That's about it really.

 

[BigPapa]

While your visual signs of an exhaust leak do indicate you have one, a whistle is typically a boost leak between the turbo and the intake. You could have a boot that’s come loose at a clamp, a hole in a boot, and I’ve even seen an intake gasket blow out. You’ll need to build or buy a “kit” to apply compressed air to the intake system. The turbo won’t develop enough pressure to test it unless it’s under load, free revving won’t do it. Apply the compressed air and use soapy water in a spray bottle just like you would a tire.

As to the Dorman manifold, I would advise against it. These are pics of a Dorman next to a DAP. I’ve used ATS and from what I’ve been told, Steed Speed is the cat’s meow but they’re pricy.

Also, not to say DB’s wrong, I’m sure the studs have worked for him or he wouldn’t recommend them, but I’ve experienced and heard of several instances where studs and nuts are hard to keep tight. Cummins uses bolts and spacers. I never had an issue with the Allen head bolts that came with the ATS. I torqued them at installation and checked them a couple of times over the following couple of months and they were tight every time.

 

[Darkbloodmon]

As to the Dorman manifold, I would advise against it. These are pics of a Dorman next to a DAP. I’ve used ATS and from what I’ve been told, Steed Speed is the cat’s meow but they’re pricy.

I don't think you could get a rougher casting than that Dorman manifold. Steed Speeds make you want to put it on a wall and just look at it. Beautiful pieces of mfg.

Not that I went looking and researching for any issues before purchasing the studs but its a first for me hearing about issues with the type of hardware as simple as it is. FWIW the nuts that came in my kit have a serrated pattern in the flange to "resist" backing off. I know in passing that ARP has manifold studs and they have a lock type nut/washer for studs as well. You can pick up the nuts that came in my kit at just about any auto parts store, its a common metric size.

By all means do your research for your own application. I'm just putting around with nearly stock injectors and the OEM boost pressures with no tuning.

 

[petersonj]

but I’ve experienced and heard of several instances where studs and nuts are hard to keep tight. Cummins uses bolts and spacers.

You are on to something here. I have no experience using studs on the exhaust manifold, but I do have experience with fasteners and what makes them stay tight. In general a fastener is sized and torqued to a value that will put the fastener in its mid range of its elastic capabilities, thus maintaining the intended clamping force under all operating conditions. When the clamping forces are met by a well engineered fastening system, the fastener will never become loose. Lock nuts, lock washers, lock tabs, and Locktite will stop a fastener from falling off, but they will not keep a fastener tight. Proper torque on a fastener with a specific hardness and length will keep a fastener tight.

@BigPapa noted, "Cummins uses bolts and spacers." In my opinion, those spacers are a critical part in maintaining the clamping force of the exhaust manifold fasteners. That spacer greatly increases the length of the fastener, thus increasing the operational distance of "stretch" of the fastener. This allows for considerable thermal expansion and contraction of the exhaust manifold to occur without the fastener losing its clamping force.

I did notice that a couple of web sites mentioned the length of the exhaust manifold studs are approximately 1.6 inches and that the original spacers could not be used. To me, that is a recipe for manifold studs to loosen repeatedly over time.

- John

 

[Darkbloodmon]

Lets not overthink this, we're not talking about head gaskets on a mild build Powerstroke.

You're going to find yourself down a rabbit hole of peak marketing in which you can only justify buying ARP products at this rate. It's hardware; it either holds or it doesn't, the only thing you can do is assemble and fasten it to mfg. spec.

The issue at hand is the manifold leak, 170K on factory bolts, Can Tuned with larger injectors.

.02 below : kinda backwards thinking to be skeptical of studs which are designed around higher clamping forces than the OEM bolts which are what seemingly failed on a low mileage (relative) engine. Or maybe they just need to be Hot torqued since the engine is just breaking in.

Its fine if you want to question the metallurgy but are you going to send out your hardware for lab testing? No mfg. is going to disclose where their steel is sourced from and what special sauce they marinate their metal bits in before they package it up and let the marketing team have at it.

At the end of the day studs are going to hold more hell, else ARP wouldn't have ground to stand on to justify their price much less their grandfathered name and brand reputation. I say this while using Xotic head studs.

If we get Heard's attorney involved in this, I believe he'd move to strike everything in this thread and on this forum as "Hearsay"

 

[BigPapa]

ARP doesn’t make exhaust studs for a Cummins. Wonder why?

 

[Darkbloodmon]

ARP doesn’t make exhaust studs for a Cummins. Wonder why?

From their site, about two thirds down on the head tab they've got part numbers for manifold studs. Ran their part number on Summit and this came up M8x1.25 sounds about right for the thread size from memory.

Here is a PDF quick reference for ARP hardware and Cummins trucks, exhaust hardware at the bottom with a few part numbers for studs.

 

[BigPapa]

They are M10-1.5.

 

[CVR222NV]

I can't speak to the science but do have personal experience with exhaust manifold studs and it was not good. I experienced an exhaust manifold leak and I replaced the stock manifold with a stainless one piece and stainless studs. The nuts kept back off. I eventually replaced that exhaust manifold when it warped. I went with a two piece from PDI but kept the studs. Nuts again kept backing off. I contacted ARP and while I do believe they used to have exhaust manifold studs for a Cummins I was told they no longer supply them because of problems so I'm surprised to see them listed in DBM's PDF attachment. I note that DBM's link to the Summit Racing site is for part number 441-1301 and not 447-1301 as indicated in the PDF from ARP. I went to the ARP site and this is what I found:

The Official ARP Web Site | Kits (arp-bolts.com) Indicates that this kit has not been released. The same applies for kit numbers 447-1303 and 447-1305 depending on the manifold. I wonder why these kits have not been released by ARP?

I went back to the bolts with spacers and since the flange on the PDI manifold is thicker I also went with slightly longer bolts and torqued them to 40 lbs (up from the OE recommended 32 lbs) all at the recommendation of PDI. No more problems with the exhaust manifold bolts becoming loose but I still check the exhaust manifold bolts at every oil change because of my experience. Just my .02.

 

[Darkbloodmon]

They are M10-1.5.

I'll take your word for it, I didn't write down the size in my log book.

 

[Darkbloodmon]

so I'm surprised to see them listed in DBM's PDF attachment. I note that DBM's link to the Summit Racing site is for part number 441-1301 and not 447-1301 as indicated in the PDF from ARP. I went to the ARP site and this is what I found:

The PDF attachment was updated last year January according to the note in the bottom right corner. My mistake on the summit link it was for a 8 count when it should've been 12 and the thread size stated by @BigPapa

I did notice that a couple of web sites mentioned the length of the exhaust manifold studs are approximately 1.6 inches and that the original spacers could not be used. To me, that is a recipe for manifold studs to loosen repeatedly over time.

The studs I sourced from PDP are 1.959" / 49.75mm

Fleece hasn't given a length on theirs. I'm sure you could call and ask but again this is all besides the point of OPs issue at hand. We can go back and forth about hardware in another thread.

 

[BigPapa]

 

[JReichenbach]

Thanks guys, I took Big Papa's advice and disassembled all the intake to turbo hoses. I had replaced all of them when I put the Banks intercooler and Air horn on. The one right off of the turbo was NOT replaced at this time. the hose showed some traces of possible leakage, so I replaced it and the clamps. We just had a blizzard, so I haven't had a chance to drive it and see if I fixed it. As far as the exhaust, I'm gonna replace all the gaskets and bolts with the factory stuff, I still have an in at local dealership. Thanks for all the insight, I will let all know what happens. Jim.

 

[JReichenbach]

Thanks guys, I took Big Papa's advice and disassembled all the intake to turbo hoses. I had replaced all of them when I put the Banks intercooler and Air horn on. The one right off of the turbo was NOT replaced at this time. the hose showed some traces of possible leakage, so I replaced it and the clamps. We just had a blizzard, so I haven't had a chance to drive it and see if I fixed it. As far as the exhaust, I'm gonna replace all the gaskets and bolts with the factory stuff, I still have an in at local dealership. Thanks for all the insight, I will let all know what happens. Jim.

Update, Finally: Found that #6 exhaust port had a leak pointing directly at firewall. Just replaced all gaskets and most of the bolts, didnt have to unhook turbo to do it. Couple hour job, put 6 or 7000 miles on since, all good now. Thanks again for tips. Jim.