Exhaust Manifolds | Warped

[RampantJourneys]

I'm well-aware that the 5.7L HEMI has a fairly common issue surrounding the exhaust manifold bolts, causing the "HEMI tick". About 10 days ago, I noticed my truck had a tapping noise when cold-started. I assumed that this was the infamous HEMI tick and honestly didn't give it much thought. It then started to get noticeably and progressively louder and more intense with each day. And where it would normally disappear after the engine warmed up, it's only getting softer, but not going away.

As of today, we are well beyond the "tick" stage. When started cold the noise sounds like a spoon being hammered around the inside of an empty coffee can. A very DEEP and very LOUD, TAP TAP TAP TAP TAP. There is no check engine or malfunction indicator lights, and operationally the truck appears to be driving perfectly fine. No discernible misfires, surging, loping or stalling. Power is always there. Oil level is fine, it runs Mobil1 Fully-Synethic 5W-20 and the oil doesn't appear out of sorts or discolored.

I took it into my local dealer to have them examine the truck and after about an hour and a half they came back with the news that both exhaust manifolds are "warped" and have got to be replaced. When I asked if the truck had a bad lifter, they said that upon initial inspection, their tests showed that all the lifters are operational and moving as they should but, they wouldn't know for sure until the vehicle is dismantled. They said that the exhaust manifold bolts would be replaced along with the manifolds themselves.

My question is, without being a knowledgeable mechanic, even I know that a lifter failure can cost you an engine with almost no effort. This is forcing me to put a huge amount of trust in the shop when they say nothing is wrong with the lifters and that it is merely the manifolds.

I would love to know what you all would do here. Unfortunately, my living situation and job do not afford me the ability to dismantle the truck myself and given the time of year and the fact that my only other vehicle is a Harley... having the truck down for a couple weeks torn apart isn't an option either.

Your input is appreciated. Thanks all!

 

[mtofell]

Not sure if this is relevant but I'll share just in case - 2014 6.4 Hemi 2500. At about 85K while going in for a routine oil change I mentioned that my truck seemed to be a bit loud in the morning when starting up. They call and tell me both exhaust manifolds have bad bolts and need to be redone. I have a lifetime Maxcare warranty so for the $100 deductible I say sure... replace them.

So, I go get my truck and when firing it up the first morning it sounds just the same. Basically, what I was hearing wasn't the manifold bolts. It really sounds more like just loose exhaust mounts or something. More of a rattle further away from the engine. Of course, I was skeptical if they actually did anything or just milked the warranty company but did see signs of a lot of work - grease stains, new nuts and bolts, etc.

I guess the only thing that could be relevant to your cause is that I never heard any tick or spoons rattling in cans but was diagnosed with bad manifold bolts.

 

[RampantJourneys]

I appreciate the input mtofell. I've done a lot of reading and watched a lot of videos on the HEMI tick caused by the bolts, but even the dealership said that the noise my truck is making is way beyond that. Sadly, they pushed it out of the service department intake lane and into the service floor just to avoid starting the engine. This is despite the fact that I'd just driven 20 minutes down the highway at 65mph to GET to the dealership and appeared to arrive just fine haha.

 

[Dpressed1]

I'm well-aware that the 5.7L HEMI has a fairly common issue surrounding the exhaust manifold bolts, causing the "HEMI tick". About 10 days ago, I noticed my truck had a tapping noise when cold-started. I assumed that this was the infamous HEMI tick and honestly didn't give it much thought. It then started to get noticeably and progressively louder and more intense with each day. And where it would normally disappear after the engine warmed up, it's only getting softer, but not going away.

As of today, we are well beyond the "tick" stage. When started cold the noise sounds like a spoon being hammered around the inside of an empty coffee can. A very DEEP and very LOUD, TAP TAP TAP TAP TAP. There is no check engine or malfunction indicator lights, and operationally the truck appears to be driving perfectly fine. No discernible misfires, surging, loping or stalling. Power is always there. Oil level is fine, it runs Mobil1 Fully-Synethic 5W-20 and the oil doesn't appear out of sorts or discolored.

I took it into my local dealer to have them examine the truck and after about an hour and a half they came back with the news that both exhaust manifolds are "warped" and have got to be replaced. When I asked if the truck had a bad lifter, they said that upon initial inspection, their tests showed that all the lifters are operational and moving as they should but, they wouldn't know for sure until the vehicle is dismantled. They said that the exhaust manifold bolts would be replaced along with the manifolds themselves.

My question is, without being a knowledgeable mechanic, even I know that a lifter failure can cost you an engine with almost no effort. This is forcing me to put a huge amount of trust in the shop when they say nothing is wrong with the lifters and that it is merely the manifolds.

I would love to know what you all would do here. Unfortunately, my living situation and job do not afford me the ability to dismantle the truck myself and given the time of year and the fact that my only other vehicle is a Harley... having the truck down for a couple weeks torn apart isn't an option either.

Your input is appreciated. Thanks all!

As a chrysler tech, usually what i do is pry the heat shield, (90% of the time in my experience, the bolts that break are the rear two that hold the shield) enough to were it is not loose rattling against anything and then allow the engine to cool down. I start it and if no tick is present, then valvetrain is good. Also, lifter tick and manifold ticks are different. Can be distinguished. But also sometimes one will cover the other, as to one being louder and not being able to hear very well the other. In your case, i would of taken the heat shield with broken bolt/s and proceed from there. If noise still present, then i would ask for engine tear down approval if not under powertrain warranty.

 

[clint440]

How many miles? You could do an oil analysis and see if you have high iron or copper which could indicate an internal problem. Exhaust related noises are unpredictable so sounds plausible on what the dealer said.

I do have a good set of iron manifolds available if you wanted to stay stock. I just put headers on my truck.

Good luck.

 

[RampantJourneys]

As a chrysler tech, usually what i do is pry the heat shield, (90% of the time in my experience, the bolts that break are the rear two that hold the shield) enough to were it is not loose rattling against anything and then allow the engine to cool down. I start it and if no tick is present, then valvetrain is good. Also, lifter tick and manifold ticks are different. Can be distinguished. But also sometimes one will cover the other, as to one being louder and not being able to hear very well the other. In your case, i would of taken the heat shield with broken bolt/s and proceed from there. If noise still present, then i would ask for engine tear down approval if not under powertrain warranty.

Thanks. That's actually good to hear because it's in line with what the dealer told me. They said the the din caused by the warped exhaust manifolds could be masking a lift tick. As a result, they want to replace the exhaust manifolds first and THEN see if there's still something gone awry. I'm just not really enjoying the though of my truck being torn apart potentially... twice. But if it means preventing a blown motor, then by all means.

 

[Fast69Mopar]

As a chrysler tech, usually what i do is pry the heat shield, (90% of the time in my experience, the bolts that break are the rear two that hold the shield) enough to were it is not loose rattling against anything and then allow the engine to cool down. I start it and if no tick is present, then valvetrain is good. Also, lifter tick and manifold ticks are different. Can be distinguished. But also sometimes one will cover the other, as to one being louder and not being able to hear very well the other. In your case, i would of taken the heat shield with broken bolt/s and proceed from there. If noise still present, then i would ask for engine tear down approval if not under powertrain warranty.

As a Chrysler Tech I agree with this method as it is exactly what I do to the HEMI trucks.

If you don't make it anywhere with the service manager give Ram Cares a call or send them a message.

I would ask for the Zone Tech to get involved and inspect the truck while it is in for service.

 

[Dpressed1]

Thanks. That's actually good to hear because it's in line with what the dealer told me. They said the the din caused by the warped exhaust manifolds could be masking a lift tick. As a result, they want to replace the exhaust manifolds first and THEN see if there's still something gone awry. I'm just not really enjoying the though of my truck being torn apart potentially... twice. But if it means preventing a blown motor, then by all means.

Honestly man, i have never seen or heard of a warped exhaust manifold. I have repaired broken manifold bolts a lot of times and never had that issue of warpage. Thats new to me. Usually after removing the manifold and extracting the broken studs, the manifold mounting surfaces gets cleaned and a new gasket with hardware gets installed. Also, a heads up, sometimes the studs will not extract in the vehicle so the head will have to be removed. Then if studs wont come out after trying to extract them in bench, the head will need to be replaced. I have heard from techs at other dealers that they send them to a machine shop to get extracted and repaired. But in the dealers i have worked at, they never recommended doing that. Not sure how well that would work. Hope any of that helps.

 

[RampantJourneys]

As a Chrysler Tech I agree with this method as it is exactly what I do to the HEMI trucks.

If you don't make it anywhere with the service manager give Ram Cares a call or send them a message.

I would ask for the Zone Tech to get involved and inspect the truck while it is in for service.

That's a nice thought, but I have serious doubts that Ram Cares will give a darn about my truck seeing as it's no longer under warranty and 10 years old. If it was 10 months old and not 10 years, maybe. I appreciate your input nonetheless though. So far the dealer hasn't given me any reason to be doubtful, so no reason to be concerned at this stage in the game. I've generally had very good luck with dealerships in my years of owning MOPARs. I've largely been very pleased with them across the board.

 

[RampantJourneys]

Honestly man, i have never seen or heard of a warped exhaust manifold. I have repaired broken manifold bolts a lot of times and never had that issue of warpage. Thats new to me. Usually after removing the manifold and extracting the broken studs, the manifold mounting surfaces gets cleaned and a new gasket with hardware gets installed. Also, a heads up, sometimes the studs will not extract in the vehicle so the head will have to be removed. Then if studs wont come out after trying to extract them in bench, the head will need to be replaced. I have heard from techs at other dealers that they send them to a machine shop to get extracted and repaired. But in the dealers i have worked at, they never recommended doing that. Not sure how well that would work. Hope any of that helps.

Good information, I appreciate this! I wish there was a good solution to solve the exhaust manifold problem so it wouldn't repeat ad infinitum, but oh well. If wishes were horses, beggars would ride.

 

[OCDTech]

Good information, I appreciate this! I wish there was a good solution to solve the exhaust manifold problem so it wouldn't repeat ad infinitum, but oh well. If wishes were horses, beggars would ride.

Just passing on what ive heard, many say shorty headers and good bolts is a pretty good fix.

 

[Dpressed1]

Just passing on what ive heard, many say shorty headers and good bolts is a pretty good fix.

I have heard and taught about that for my ram. But they are pricy!!

 

[OCDTech]

I have heard and taught about that for my ram. But they are pricy!!

boosted motorsports on youtube has a really good how to on this.

I would consider it but i don't want to tune.....yet.

 

[Fast69Mopar]

That's a nice thought, but I have serious doubts that Ram Cares will give a darn about my truck seeing as it's no longer under warranty and 10 years old. If it was 10 months old and not 10 years, maybe. I appreciate your input nonetheless though. So far the dealer hasn't given me any reason to be doubtful, so no reason to be concerned at this stage in the game. I've generally had very good luck with dealerships in my years of owning MOPARs. I've largely been very pleased with them across the board.

Sorry I must have misread your post as I did not realize what year model your DR truck is. If you can do the mechanical work yourself and get the exhaust manifolds off of the engine, take them to your local machine shop and have them milled or "belt-sanded" for about $50.00 and be done with it. Once the exhaust manifolds have warped and then milled for flatness you wont ever have a problem again.

I pull these manifolds off on damn near a daily basis on my customers trucks and run them on my large belt sander or my mill to clean them up. My local machine shop only charges a flat fee of $50.00 to clean up a set of manifolds if I don't have the time to get to them.

 

[Fast69Mopar]

Honestly man, i have never seen or heard of a warped exhaust manifold. I have repaired broken manifold bolts a lot of times and never had that issue of warpage. Thats new to me. Usually after removing the manifold and extracting the broken studs, the manifold mounting surfaces gets cleaned and a new gasket with hardware gets installed. Also, a heads up, sometimes the studs will not extract in the vehicle so the head will have to be removed. Then if studs wont come out after trying to extract them in bench, the head will need to be replaced. I have heard from techs at other dealers that they send them to a machine shop to get extracted and repaired. But in the dealers i have worked at, they never recommended doing that. Not sure how well that would work. Hope any of that helps.

I see warped 5.7 HEMI exhaust manifolds all the time. Here are a few pics of the last set I milled from a 2004 DR that I bought. As you can see in the pics one of the ports on the end is flat and the other end of one manifold has an 1/8" gap showing light and the other had a 3/16" gap.

 

[RampantJourneys]

I see warped 5.7 HEMI exhaust manifolds all the time. Here are a few pics of the last set I milled from a 2004 DR that I bought. As you can see in the pics one of the ports on the end is flat and the other end of one manifold has an 1/8" gap showing light and the other had a 3/16" gap.View attachment 191584

View attachment 191583

View attachment 191585

View attachment 191587

This is stunning to me. I've never had a car that's had this problem before, or that had it as such a prevalent issue across the model. I wonder if the warped manifolds are due to poor materials or a bad design. I guess what I'm wondering is, if a technician sees warped heads all the time, I wonder how often I'll be looking forward to this repair, you know?

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[Fast69Mopar]

This is stunning to me. I've never had a car that's had this problem before, or that had it as such a prevalent issue across the model. I wonder if the warped manifolds are due to poor materials or a bad design. I guess what I'm wondering is, if a technician sees warped heads all the time, I wonder how often I'll be looking forward to this repair, you know?

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At my dealership in Texas we repair broken exhaust manifold bolts and warped manifolds on a regular basis. I started repairing broken bolts on 5.7 HEMI's back in 2005-2006. I didn't start belt sanding the manifolds in the dealership until 2008.

One thing that drives me crazy is all the HEMI trucks that live on my street have broken bolts and exhaust leaks. That is one of my pet peeves. I despise exhaust leaks. I hear my neighbor fire his up and it makes me crazy. Last year I got worn out on repairing broken bolts at the shop so I had to teach a young mechanic how to do it so I could take a break.

When I am working from my own shop at home I do at least 2 trucks per weeks with broken bolts. So far I have never had one that has been repaired come back with a leak or a broken bolt after the manifolds have been resurfaced.

 

[OCDTech]

At my dealership in Texas we repair broken exhaust manifold bolts and warped manifolds on a regular basis. I started repairing broken bolts on 5.7 HEMI's back in 2005-2006. I didn't start belt sanding the manifolds in the dealership until 2008.

One thing that drives me crazy is all the HEMI trucks that live on my street have broken bolts and exhaust leaks. That is one of my pet peeves. I despise exhaust leaks. I hear my neighbor fire his up and it makes me crazy. Last year I got worn out on repairing broken bolts at the shop so I had to teach a young mechanic how to do it so I could take a break.

When I am working from my own shop at home I don't least 2 trucks per weeks with broken bolts. So far I have never had one that has been repaired come back with a leak or a broken bolt after the manifolds have been resurfaced.

So is this caused? Or are they warped when made?

Assuming made if sanding fixes permanently. I know others will love to know this too.


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[crackerjack1957]

Exhaust manifolds should have been stress relieved before final machining from manufacturer.
This is why seasoned manifolds will not warp again after machined flat.

Stress Relieving – Soak Temperature 1100-1200˚

 

[Fast69Mopar]

So is this caused? Or are they warped when made?

Assuming made if sanding fixes permanently. I know others will love to know this too.

The exhaust manifolds are relatively flat when when new. Most measure in the .001"-.002" range from end to end which is in spec. I have had several with a .008" - .011" difference from end to end when they were new out of the box. Those were the worst case scenarios. I actually ran them on the belt sander before installation so I wouldn't have a damn recheck even though I didn't get paid to correct a new part. It's just part of being a tech.

I talked to my zone tech back in 2008 about the warped manifolds and broken bolts on so many of the HEMI trucks. In my opinion they are a poor design. They have zero as-cast rigidity or support webbing to strengthen the material and my zone tech agreed. We had a rash of warranty claims that Chrysler didn't want to pay until our zone tech and the zone warranty administrator inspected the manifolds that were being returned under warranty. Our parts department had a 4'x4'x4' box on a pallet full of exhaust manifolds waiting to be returned. Once the 3rd Gen trucks began to fade out of warranty and the 4th Gen trucks were getting some age and miles under their belts we started all over again with broken bolts and warped manifolds.

Around early 2014 we started seeing the same thing all over again but this time it was worse.

Once the exhaust manifolds become warped and the material has moved it is normally at a point where any more warpage would be so minimal that the gaskets take up the slack to prevent leaks. We have some techs in our shop who after extracting the broken bolts reinstalled the warped manifolds with new gaskets only to have them break the new bolts withing a few hundred miles. If you looked at my pics you can see how much of a gap there is from end to end. The bolts can only take so much torque when attempting to clamp down a manifold.


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