Exhaust manifold bolts

[ButchT]

A newbie here - have mercy! I recently purchased a 2018 Ram Bighorn Hemi with 129,000 miles. Is there an obvious way to determine if the problematic exhaust manifold bolts were ever replaced? Thank you!

 

[Hagar1]

A newbie here - have mercy! I recently purchased a 2018 Ram Bighorn Hemi with 129,000 miles. Is there an obvious way to determine if the problematic exhaust manifold bolts were ever replaced? Thank you!

The manifolds may have not warped enough yet to cause the bolts to break. When and if they do, get your existing manifolds resurfaced because a new manifold will put you right back to the beginning of the problem.

 

[express2014]

shake the heatshields over the manifolds at the rear. if it moves you have broken bolts.

 

[ButchT]

Thank you both!

 

[Adamcr68]

A newbie here - have mercy! I recently purchased a 2018 Ram Bighorn Hemi with 129,000 miles. Is there an obvious way to determine if the problematic exhaust manifold bolts were ever replaced? Thank you!

Not always the case but if you hear a tick at start up that lessens when the engine warms up, metal expanding, frequently broken bolts most likely in the rear. Hemis are noisy engines between the injectors and lifters, ticks can be hard to determine.
When I had long tubes put on my truck had 3 bolts broken, all in the back, I was upgrading my exhaust by choice never really noticed a tick.

 

[mikeru]

A newbie here - have mercy! I recently purchased a 2018 Ram Bighorn Hemi with 129,000 miles. Is there an obvious way to determine if the problematic exhaust manifold bolts were ever replaced? Thank you!

Seems like your question was not answered yet. If I'm not mistaken, you didn't ask how to tell if you have broken bolts, but whether there is a way to tell if any bolts were replaced on this truck by a previous owner. If that's what you're asking I'd contact a dealership and see if they can look that up. If I'm not mistaken there should be records of any work performed by a dealership. Someone please correct me if my assumption is wrong on that.

 

[Slinge]

common practice is to leave off the heat shields when taking off exh manifolds.
if you dont have heat shields , its a good sign someones been in there

 

[Nick@GotExhaust]

Seems like your question was not answered yet. If I'm not mistaken, you didn't ask how to tell if you have broken bolts, but whether there is a way to tell if any bolts were replaced on this truck by a previous owner. If that's what you're asking I'd contact a dealership and see if they can look that up. If I'm not mistaken there should be records of any work performed by a dealership. Someone please correct me if my assumption is wrong on that.

In addition to what was said above. New manifold bolts do not mean you are in the clear from having warped manifolds and broken bolts. The issue is not the hardware, its the manifolds themselves. They warp and that is what causes the bolts to break. There are a few options if this happens to you or if you plan to make the change before it does. For replacement options that wont warp or crack we reccomend either the BD manifolds, AFE shorties, or Stainless Works Long tubes. Message me if you would like more info and/or a quote on anything.

 

[ButchT]

Thanks, yes, I wanted to know if there was readily available way to determine whether or not the bolts have been replaced already. Dealer contact is not available unless all dealers have access to records of other dealers performing service for this vehicle.

 

[Nick@GotExhaust]

Thanks, yes, I wanted to know if there was readily available way to determine whether or not the bolts have been replaced already. Dealer contact is not available unless all dealers have access to records of other dealers performing service for this vehicle.

I would contact your local dealer and see if they have access to that info but as mentioned earlier. Even if they were replaced, the bolts are not the cause of the issue, them breaking is the result of the issue, which is the manifolds warping. So whether they have been replaced or not doesnt matter if they bolted in stock manifolds. Eventually they will warp (and possibly crack) and then break the bolts. The manifolds flange where it meets the head is what warps and puts pressure on those bolts and eventually snaps them

 

[Skydog73]

Thanks, yes, I wanted to know if there was readily available way to determine whether or not the bolts have been replaced already. Dealer contact is not available unless all dealers have access to records of other dealers performing service for this vehicle.

i had a 2016 for a short time. it had the tick that would go away when it warmed up. i took it to an exhaust shop. manifold warped and bolts breaking. they fixed all that and they added a new CAT back to it.

that truck only had 59k on it at the time. exhaust guy said he had never seen one warped that soon.

i traded it later because of even more issues but the tick was resolved with the manifold and exhaust work.

 

[04fxdwgi]

Seems like your question was not answered yet. If I'm not mistaken, you didn't ask how to tell if you have broken bolts, but whether there is a way to tell if any bolts were replaced on this truck by a previous owner. If that's what you're asking I'd contact a dealership and see if they can look that up. If I'm not mistaken there should be records of any work performed by a dealership. Someone please correct me if my assumption is wrong on that.

Only if it was done at a dealer. A local shop (or a shade tree) wouldn't be in any report. There really is no absolute way of telling just looking at them, unless some look new and not being at all rusty.

 

[Johnny Paycheck]

that truck only had 59k on it at the time. exhaust guy said he had never seen one warped that soon.

Really? My ‘18 sprang a leak on the passenger’s side around 62K miles…which is right about where the crew cab did right after I bought it last summer. It’s finally about to make a visit to have both sides sanded

 

[Adamcr68]

Seems like your question was not answered yet. If I'm not mistaken, you didn't ask how to tell if you have broken bolts, but whether there is a way to tell if any bolts were replaced on this truck by a previous owner. If that's what you're asking I'd contact a dealership and see if they can look that up. If I'm not mistaken there should be records of any work performed by a dealership. Someone please correct me if my assumption is wrong on that.

Your reading comprehension definitely better than mine, good catch!

 

[mikeru]

Only if it was done at a dealer. A local shop (or a shade tree) wouldn't be in any report. There really is no absolute way of telling just looking at them, unless some look new and not being at all rusty.

I kind of figured that went without saying but I appreciate your pointing that out.

Your reading comprehension definitely better than mine, good catch!

Haha thanks...maybe I was just having an enlightened moment.

 

[ButchT]

Pardon my ignorance, but I believe I have it all wrong. I thought that the bolts sheared because of differing metals’ reactions to high temperatures. To avoid damaging the manifold I should replace the OEM bolts with different bolts prior to their failure. So I wanted to know of a way to determine if the “faulty” OEM bolts were already replaced with “correct” bolts thereby avoiding potential subsequent damage to the manifold if and when the OEM bolts would bend or shear. I reasoned that if the OEM bolts were replaced then I would avoid damage to the manifold - problem solved.

Now I believe what I am being told is that the defect begins with the manifold warping thereby causing the bolts to shear - not the other way around. What I have to correct is the manifold part to avoid causing the bolts to shear? And, if the bolts shear I have to replace the bolts and also repair the manifold that caused them to shear. So, the bolts’ shearing is a symptom that tells me I have a warped manifold. Should I perform some sort of preventative maintenance to avoid the manifold warping and causing the bolts to shear? (I am using the tern “shear” to mean any failure of the bolts.) Thank you very much for any clarification!

 

[04fxdwgi]

Correct. The warped manifold causes the bolts to shear due to the quite short length of the bolts. Manifold manufacturers like BD Diesel, provide a longer bolts and thick spacers so the bolts can actually stretch with out breaking.

There is actually nothing you can do to the OEM's to prevent warping. It's caused by how they are made and warp from heat cycles and sketchy design.

But the good thing is once they warp. they normally don't do it again,. Putting these manifolds on a cheap belt sander, like a $75 Harbor freight 24" one, and sanding it flat, it will probably be flat the rest of it's life.

 

[mdc1990zr1]

Pardon my ignorance, but I believe I have it all wrong. I thought that the bolts sheared because of differing metals’ reactions to high temperatures. To avoid damaging the manifold I should replace the OEM bolts with different bolts prior to their failure. So I wanted to know of a way to determine if the “faulty” OEM bolts were already replaced with “correct” bolts thereby avoiding potential subsequent damage to the manifold if and when the OEM bolts would bend or shear. I reasoned that if the OEM bolts were replaced then I would avoid damage to the manifold - problem solved.

Now I believe what I am being told is that the defect begins with the manifold warping thereby causing the bolts to shear - not the other way around. What I have to correct is the manifold part to avoid causing the bolts to shear? And, if the bolts shear I have to replace the bolts and also repair the manifold that caused them to shear. So, the bolts’ shearing is a symptom that tells me I have a warped manifold. Should I perform some sort of preventative maintenance to avoid the manifold warping and causing the bolts to shear? (I am using the tern “shear” to mean any failure of the bolts.) Thank you very much for any clarification!

You are correct. I always believed that the heat shields being bolted on with a second nut prevented the ‘stretch’ needed for expansion and contraction. The BD manifold engineers must have also thought of that and position the heat shields using a separate and independent mounting position.

 

[Slinge]

The bolts breaking is a good thing.
Way better than pulling the threads out of an aluminum head.

 

[EdGs]

As @04fxdwgi said, if you just want to fix the warped exhaust manifold issue, belt sand them flat or have them machined flat, replace the hardware, and you shouldn't have any more problems with warping.

It does take time to get them flat with a belt sander, but it is very doable.

The rear-most bolt on both sides were broken on my truck. Fortunately, they broke off just under the head of the stud and left part of the stud sticking out. I was able to unscrew them once I removed the manifolds. I belt-sanded the manifolds and used everbuilt hardware from Amazon with no issues since 106k miles (I'm over 210k miles now).

If your exhaust manifold bolts are broken off flush with the cylinder head, the preferred method for extraction is to weld a washer and nut to the broken stud and unscrew them.