Replacing m156 manifold DIY?
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Junior Member
Joined: Jun 2024
Posts: 17
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C63 s204
Replacing m156 manifold DIY?
I’m planning to install a new intake manifold and considering doing it myself. The car is in good condition and runs fine (no error codes or issues).
The main reason for replacing the manifold is preventative maintenance; the paint layer shows some blisters and some chips of paint are gone, unsure if this is corrosion related, but that something to find out afterwards.
I want to do it myself so I can take my time, see exactly what’s going on, and because I enjoy working on the car. It’s not my daily driver, so having it off the road for a while isn’t a problem.
The manifold is completely new, so there’s no need to transfer parts like the throttle body or throttle plate.I’ve read and watched all the guides I can find, and I feel I have a fairly good understanding of the process.
Based on the car’s history and other things I’ve noticed, I don’t think the manifold has been removed before, so I’m not expecting issues like broken bolts.
I already have new gaskets, new bolts, a new PCV, a catch can, and several vacuum hoses (like the brake booster) that I’ll replace at the same time, as well as the injectors. I also have the torque specs (just need to get a good torque wrench).
What’s making me hesitate is that if there turns out to be a lot of carbon buildup in the intake ports for example, I probably won’t be able to clean it myself?
The bigger concern, in my opinion, is that if something is wrong afterwards, such as a vacuum leak from a hose not being connected properly or the gaskets not sealing properly or something, I might not be able to detect it.
I can read some fault codes with a youcanic, but it won’t cover everything, and I’m not sure how quickly vacuum leaks would trigger fault codes, if at all?
So, mainly looking for general advice, is this job realistically doable without formal mechanical experience, assuming I’ve done my research and prepared properly?
Is there stuff that can go wrong that can remain undected afterwards ? Because as long as it throws codes or a CEL I at least know something is wrong and can bring it to a mechanic afterwards if I´m unable to fix it myself.
The main reason for replacing the manifold is preventative maintenance; the paint layer shows some blisters and some chips of paint are gone, unsure if this is corrosion related, but that something to find out afterwards.
I want to do it myself so I can take my time, see exactly what’s going on, and because I enjoy working on the car. It’s not my daily driver, so having it off the road for a while isn’t a problem.
The manifold is completely new, so there’s no need to transfer parts like the throttle body or throttle plate.I’ve read and watched all the guides I can find, and I feel I have a fairly good understanding of the process.
Based on the car’s history and other things I’ve noticed, I don’t think the manifold has been removed before, so I’m not expecting issues like broken bolts.
I already have new gaskets, new bolts, a new PCV, a catch can, and several vacuum hoses (like the brake booster) that I’ll replace at the same time, as well as the injectors. I also have the torque specs (just need to get a good torque wrench).
What’s making me hesitate is that if there turns out to be a lot of carbon buildup in the intake ports for example, I probably won’t be able to clean it myself?
The bigger concern, in my opinion, is that if something is wrong afterwards, such as a vacuum leak from a hose not being connected properly or the gaskets not sealing properly or something, I might not be able to detect it.
I can read some fault codes with a youcanic, but it won’t cover everything, and I’m not sure how quickly vacuum leaks would trigger fault codes, if at all?
So, mainly looking for general advice, is this job realistically doable without formal mechanical experience, assuming I’ve done my research and prepared properly?
Is there stuff that can go wrong that can remain undected afterwards ? Because as long as it throws codes or a CEL I at least know something is wrong and can bring it to a mechanic afterwards if I´m unable to fix it myself.
Last edited by JohnMerc63; Jan 10, 2026 at 01:06 PM.
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Joined: Mar 2010
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From: CH = Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Sorry, can't help you with your query as I've never had to go down that road (yet) with my intake, but have you checked the stickies? It may have something which could confirm you are going down the right path. Or someone more knowledgeable may chime in soon. This page has become much quieter these days...
https://mbworld.org/forums/c63-amg-w...-stickies.html
https://mbworld.org/forums/c63-amg-w...-stickies.html
Newbie
Joined: Jul 2023
Posts: 11
Likes: 8
From: Iowa
2013 c63
I’m planning to install a new intake manifold and considering doing it myself. The car is in good condition and runs fine (no error codes or issues).
The main reason for replacing the manifold is preventative maintenance; the paint layer shows some blisters and some chips of paint are gone, unsure if this is corrosion related, but that something to find out afterwards.
I want to do it myself so I can take my time, see exactly what’s going on, and because I enjoy working on the car. It’s not my daily driver, so having it off the road for a while isn’t a problem.
The manifold is completely new, so there’s no need to transfer parts like the throttle body or throttle plate.I’ve read and watched all the guides I can find, and I feel I have a fairly good understanding of the process.
Based on the car’s history and other things I’ve noticed, I don’t think the manifold has been removed before, so I’m not expecting issues like broken bolts.
I already have new gaskets, new bolts, a new PCV, a catch can, and several vacuum hoses (like the brake booster) that I’ll replace at the same time, as well as the injectors. I also have the torque specs (just need to get a good torque wrench).
What’s making me hesitate is that if there turns out to be a lot of carbon buildup in the intake ports for example, I probably won’t be able to clean it myself?
The bigger concern, in my opinion, is that if something is wrong afterwards, such as a vacuum leak from a hose not being connected properly or the gaskets not sealing properly or something, I might not be able to detect it.
I can read some fault codes with a youcanic, but it won’t cover everything, and I’m not sure how quickly vacuum leaks would trigger fault codes, if at all?
So, mainly looking for general advice, is this job realistically doable without formal mechanical experience, assuming I’ve done my research and prepared properly?
Is there stuff that can go wrong that can remain undected afterwards ? Because as long as it throws codes or a CEL I at least know something is wrong and can bring it to a mechanic afterwards if I´m unable to fix it myself.
The main reason for replacing the manifold is preventative maintenance; the paint layer shows some blisters and some chips of paint are gone, unsure if this is corrosion related, but that something to find out afterwards.
I want to do it myself so I can take my time, see exactly what’s going on, and because I enjoy working on the car. It’s not my daily driver, so having it off the road for a while isn’t a problem.
The manifold is completely new, so there’s no need to transfer parts like the throttle body or throttle plate.I’ve read and watched all the guides I can find, and I feel I have a fairly good understanding of the process.
Based on the car’s history and other things I’ve noticed, I don’t think the manifold has been removed before, so I’m not expecting issues like broken bolts.
I already have new gaskets, new bolts, a new PCV, a catch can, and several vacuum hoses (like the brake booster) that I’ll replace at the same time, as well as the injectors. I also have the torque specs (just need to get a good torque wrench).
What’s making me hesitate is that if there turns out to be a lot of carbon buildup in the intake ports for example, I probably won’t be able to clean it myself?
The bigger concern, in my opinion, is that if something is wrong afterwards, such as a vacuum leak from a hose not being connected properly or the gaskets not sealing properly or something, I might not be able to detect it.
I can read some fault codes with a youcanic, but it won’t cover everything, and I’m not sure how quickly vacuum leaks would trigger fault codes, if at all?
So, mainly looking for general advice, is this job realistically doable without formal mechanical experience, assuming I’ve done my research and prepared properly?
Is there stuff that can go wrong that can remain undected afterwards ? Because as long as it throws codes or a CEL I at least know something is wrong and can bring it to a mechanic afterwards if I´m unable to fix it myself.
These engines are not difficult to work on. It’s unlikely you will mess anything up if you are paying attention. It does help to have an extra set of hands when you are ready to lift the entire unit out/ set new one back in. It’s doable by your self tho.
If you do have a vacuum leak, you will know pretty much right of way. Even if you don’t get a cel. If you are even halfway in-tune with your vehicle, you will know. It could be frustrating, but it’s not a big deal.
There is a lot of info on this already in the forum. If you have any issues, check that out first. If you still cant figure it out. Come back and ask us here. You got it man, good luck.
