Cracked Exhaust Manifold

[G-Ride990]

Not my truck.

My dad has been complaining about a little tick at start up on his 2021 Bighorn 5.7 2wd truck with 47k miles. I told him to check the manifold bolts. Well he finally got around to doing it and he sent me this picture this morning.

I don't remember seeing much about this on the forum.

He's not one to go throw long tubes and a tune on his truck so he's just going to order another OEM manifold or see if the dealer will cover it under his powertrain warranty. But, is this common?

 

[mrack]

Apparently that metal piece running across the bolts on newer trucks is causing the manifolds to crack rather then snap the bolts. So I hear anyways. Pick your poison

 

[G-Ride990]

Helped my dad get the manifold swapped out this weekend.

Looks like there is a different part number on the new manifold, slight changes to the design but nothing drastic. Wonder how this new one will hold up.

Wasn't too bad, way easier than putting the LTs on my 4th gen. The dipstick is easier to mess with on his 5th gen too. Took us about 3 hours or so. And I was rotating my tires at the same time he worked on his truck.

From what the dealer told us, you can only buy the manifold as a kit now. And it came with everything including extra bolts for about $200ish from what my dad told me. I didn't double check what it cost but that seems pretty dang cheap!

I'd much rather break the manifold over bolts with how easy this was and since the kit comes complete.

 

[Wild one]

Helped my dad get the manifold swapped out this weekend.

Looks like there is a different part number on the new manifold, slight changes to the design but nothing drastic. Wonder how this new one will hold up.

Wasn't too bad, way easier than putting the LTs on my 4th gen. The dipstick is easier to mess with on his 5th gen too. Took us about 3 hours or so. And I was rotating my tires at the same time he worked on his truck.

From what the dealer told us, you can only buy the manifold as a kit now. And it came with everything including extra bolts for about $200ish from what my dad told me. I didn't double check what it cost but that seems pretty dang cheap!

I'd much rather break the manifold over bolts with how easy this was and since the kit comes complete.

Keep us updated on how they pan out G,as i'm wondering if this might be an upgrade that'd also work on the 4th Gens.
That would be $200 per side i'm guessing

 

[G-Ride990]

Keep us updated on how they pan out G,as i'm wondering if this might be an upgrade that'd also work on the 4th Gens.
That would be $200 per side i'm guessing

Will do. I am expecting to have to put some in my truck eventually too so I wanted to help out and see how bad of a job it was. Yeah $200 a side. He only replaced one.

I don't remember off the top of my head how the 4th gen manifold looks but, looking at the upgraded BD diesel version of the 4th gen manifold, it looks like the collector doesn't have as much of a bend as the 5th gen collector does. He was planning on getting BD's until he realized his truck was a DT.

Here's the BD 4th gen for comparison.

 

[mikeru]

I've seen quite a few reports of cracked exhaust manifolds on 5th gens, so it's fairly common apparently. They all seem to crack in that same spot. At least the pics I saw showed that. Not sure which is worse, although once out of warranty I'd rather swap out a manifold than have to extract a broken bolt out of the head.

 

[G-Ride990]

I've seen quite a few reports of cracked exhaust manifolds on 5th gens, so it's fairly common apparently. They all seem to crack in that same spot. At least the pics I saw showed that. Not sure which is worse, although once out of warranty I'd rather swap out a manifold than have to extract a broken bolt out of the head.

Answered my own question...

I agree, removing those broken bolts was a pain in my 2016. I'd rather swap out a manifold log.

 

[soccs11]

I just received a report from my mechanic that both my manifolds on my 2021 RAM 1500 are cracked. He called a local dealer that told him that he has 16 on order and he would not be able to put in another order until Oct. 15. Says that he is seeing this problem often. I called RAM to ask if they were helping truck owners with this problem and you can guess the answer. Now I just wait. Does anyone have any thoughts?

 

[Hellcatsrock]

Get rid of that factory junk. I bought my new ones from BD oil with gaskets and bolts for $513 shipped. One weighs almost 2 lbs more than the factory one, and the other is over a pound more. They shipped in 2 days.

 

[Dodge 1500 4X4]

I don't remember off the top of my head how the 4th gen manifold looks but, looking at the upgraded BD diesel version of the 4th gen manifold, it looks like the collector doesn't have as much of a bend as the 5th gen collector does. He was planning on getting BD's until he realized his truck was a DT.

Hay G-Ride990 BD Diesel now have the exhaust manifold kit for the DT's, I just purchased them they fit great, I had a cracked one on my driver's side.

 

[PA Ram]

Get rid of that factory junk. I bought my new ones from BD oil with gaskets and bolts for $513 shipped. One weighs almost 2 lbs more than the factory one, and the other is over a pound more. They shipped in 2 days.

I put BD diesel manifolds on my 2017 Ram 1500 due to broken bolts, they're heavier duty and have better bolt system which should alleviate bolts breaking.

 

[G-Ride990]

Well, my dad just swapped out his passenger side manifold this weekend too. Sent me this picture this morning.

Bummer

 

[TRK_GANG74]

Well I just joined the cracked manifold club today. Went in for a front right turn signal out message periodically and was told my headlight has a internal short and the passenger exhaust manifold is cracked. Both are being taken care of with my extended warranty so I’ll only be out $100. Now it’s a waiting game for the parts to come in hopefully before this snow storm hits on Wed and Thur this week.

 

[TRK_GANG74]

My parts were overnighted and arrived this morning! Truck gets dropped off on Friday morning while I wait for it at the dealer.

 

[TRK_GANG74]

Well the female service advisor screwed up. She told me Tuesday all my parts came in overnighted. She didn’t read the entire service order and missed that the manifold was included on the order and only my new front right headlight assembly came in!. The front right manifold is still on order and they don’t know when it will be here. From my last conversation with the parts guy hopefully in about a week it will be here. He is usually spot on with delivery times. At least I got the new headlight done today so that’s a partial win.

 

[TRK_GANG74]

Finally fixed today and no more ticking and pppfffttt sound from the exhaust manifold. Took them only about 3 hours after dropping the truck off last night using the night drop box. Drivers side manifold is still holding up well. Had the service rep get me pics of the crack and heat shield .

 

[PA Ram]

Apparently that metal piece running across the bolts on newer trucks is causing the manifolds to crack rather then snap the bolts. So I hear anyways. Pick your poison

I would have rather dealt with a cracked manifold then having to weld nuts on to extract broken bolts. Same bolt on both side was snapped off and bolt next to it snapped while removing. It was the bolt in the back nearest to the firewall. I put BD Diesel manifolds on that are heavier duty and have sleeves in between bolt and manifold to allow for expansion without snapping bolts. Makes me wonder why they never changed the design even though snapping bolts was common. Have had the passenger side on since last April and driver side on since August. Only issue I had was the collector sealing on both sides. I ended up using a high temp sealant and finally got a good seal. The ticking was worse after replacing then the original tick. I'm pretty sure they'll hold up longer then I'll own the truck. Next up is a 3/4 ton when I'm ready for a new truck.

 

[Guyfromthenorth]

Hey everyone, pretty sure my 2019 5th gen is joining the manifold club. I have a noticeable exhaust tick on the passenger side when cold, disappears above idle RPM. I'm going to tear into it later this week to inspect but had a couple questions I'm hoping everyone can answer for me.

1) With the BD manifolds listed here can you just swap 1 bank at a time? Just curious if the interior chambers are different volume than stock and if swapping just 1 would cause me problems in exhaust balance. If my drivers side manifold isn't cracked (yet) I don't want to spend the money on a new mani for it yet.

2) I know 4th gens broke bolts just from expansion\contraction or whatever causes it. But has anyone who has replaced 5th gen manifolds run into bolts snapping off while trying to remove them? Tbh the job doesn't look that bad...unless bolts start snapping off. I'm really hoping to not have to find a way to drill in and use an ez-out in that space, not sure I'll fit well enough to trust my drill to run straight. I know I always hear rumors of exhaust manifolds snapping off bolts when worked on, but I'm hoping mine only being 5 or so years old may have better luck...

3) The tick isn't huge right now, but noticeable at idle. Am I going to hurt anything driving on it the way it is for now until I can have a look? I don't imagine it's losing a TON of exhaust backpressure as is so I don't see it severely leaning out one cylinder, but not positive on this assumption. Obviously is this was a 2 stroke, different story.

My plan at this point is to go in through the wheel well and try to see if the tick\leak is at the manifold or the flare\donut connection. If it is the manifold I was thinking I would at least try turning each bolt 1 turn and if none snap off I'll order a new part. If even 1 snaps off odds are I'll limp it to a shop and pay the price. I'm not the worst with snapped bolt extractors, but drilling in around the aluminum head makes me nervous.

 

[rzr6-4]

1) With the BD manifolds listed here can you just swap 1 bank at a time? Just curious if the interior chambers are different volume than stock and if swapping just 1 would cause me problems in exhaust balance. If my drivers side manifold isn't cracked (yet) I don't want to spend the money on a new mani for it yet.

I doubt that would have any pressure difference, but even if it did I'm sure it would be just fine.

3) The tick isn't huge right now, but noticeable at idle. Am I going to hurt anything driving on it the way it is for now until I can have a look? I don't imagine it's losing a TON of exhaust backpressure as is so I don't see it severely leaning out one cylinder, but not positive on this assumption. Obviously is this was a 2 stroke, different story.

I had to ignore mine for a couple months until I had time to do it. By the time I got around to it, mine sounded like a type writer from across the parking lot, it was awful. Your small tick won't hurt anything. Every now and then I hear Rams drive by with an obvious leak. I suspect some of those have been that way for a while.

Given asymmetric exhaust routing combined with exhaust leaks (typically older cars but not necessarily), differences in back pressure from one side to another are pretty much a given, don't let that get you all worked up about hurting your engine. Plugged cat, sure. Cracked manifold, no.

 

[Guyfromthenorth]

I doubt that would have any pressure difference, but even if it did I'm sure it would be just fine.



I had to ignore mine for a couple months until I had time to do it. By the time I got around to it, mine sounded like a type writer from across the parking lot, it was awful. Your small tick won't hurt anything. Every now and then I hear Rams drive by with an obvious leak. I suspect some of those have been that way for a while.

Given asymmetric exhaust routing combined with exhaust leaks (typically older cars but not necessarily), differences in back pressure from one side to another are pretty much a given, don't let that get you all worked up about hurting your engine. Plugged cat, sure. Cracked manifold, no.

I appreciate the reply Rzr6, thanks!