komp55

I spent some time on Saturday installing a set of headers. To assist others who may be considering a similar upgrade, I took several pictures and will describe the process I followed. There may be others ways to tackle this project; this is what worked for me.

It's a good idea to make sure you have the right tools on hand before starting. For this project, you will need a thin body E12 torx socket (to detach exhaust system from manifolds), a T27 torx bit (coil packs), a variety of 10mm sockets and wrenches (nuts for manifolds), and 13mm and 12mm wrenches and sockets (exhaust system removal). With these surprisingly few tools, you can have at it.

I decided to start from the top and work down. Here's a shot of the engine with the front cover and air tubes removed:



Next step is to remove the air boxes as an assembly. Here's a shot of the small lever that attaches the air inlet "Y" connector to the throttle body. To remove it, simply lift up the tab. The boxes are then removed by lifting them out of their retaining clips.



There is a breather tube that connects to the driver side air tube that needs to be disconnected. It is removed by pulling the fitting out of the hose.



Here's a shot of the top of the engine following removal of the covers and air boxes.



With the air boxes removed, next step is to remove the spark plug wires and coil packs. Here's a shot with one side removed:



With the top cleared off, next step is to remove the front half of the exhaust system. First step is to disconnect the primary and secondary O2 sensors. All four connectors are located in close proximity and are easy to disconnect. Here's a shot of the connectors:



Once you've disconnected the O2 sensors, be sure to free the individual wires from their holding brackets such that the wires are hanging free from the exhaust pipes. You're now ready to tackle the exhaust system removal. Here's a shot of the two torx screws that attach the cats to the exhaust manifold:



Removing the exhaust is pretty straight forward. The front half consists of two pieces, the driver's side section (big) and the passenger side section (small). It's easiest to remove the passenger side section first. Loosen the band bracket securing it at the rear, the two 13mm nuts attaching it to the side support brackets, and finally the two torx screws securing it to the manifold. Since I was using my lift, I positioned a telescoping jack stand under the catalyst to support its weight as I lowered it from the manifold.

The driver's side section requires the additional steps of removing a supporting cross brace, and disconnecting the four screws that secure the front section of the exhaust to the rear section. There is no ring band on the driver's side since its attachment is the four screws at the rear. The screws have a 13mm head and a 12mm attaching locknut.

Here's a shot of the front exhaust section showing the crossover pipe before the secondary cats. Because this pipe is there, there is no reason I am aware of from a performance standpoint to install a second H-pipe or X-pipe further back in the system, such as in lieu of the resonator.



With the front half of the exhaust system removed, it's now time to tackle the little 10mm copper locknuts that secure the manifold to the head. Since I was working underneath the car for the exhaust removal, it made sense to remove the bottom manifold nuts first. All I can say is removing these is a true PITA, and requires patience because access and space is very tight on some of them. You end up sticking your arm up into places beneath the engine you didn't know it would fit. Here's a topside shot of the passenger side with the manifold removed:



And here's the view from the bottom, showing the exhaust ports:



Note that in several cases, removing the locknut actually caused the stud to back out of the cylinder head. It's not a bad idea to have some new studs on hand to replace those that back out. Alternatively, you can in some cases also remove the nut from the stud once it's off the engine. Your choice. Not sure if it was necessary, but I used a small amount of anti-seize on the studs I replaced. I should also mention here that I bought 16 new locknuts to use in attaching the headers. Better than having to go back in later to retighten.

The actual header is fitted from below. I installed new gaskets. A tip is that one bolt hole of each gasket has a little tab that extends into the bolt hole area. This enables the gasket to stay in place on the stud. So when you install the gaskets, put the tabbed hole on the bottom so the gasket doesn't slide off the studs. With the gaskets in place, you work the header into position and then slide it onto the studs. Because the shape is more complex than the factory log manifold, you first think you will never get some of the nuts to attach, but they do. Again, patience and persistence is required. Here's a shot of the passenger side header as viewed from the top:



And the view from bottom:



The same process is followed on the driver's side, except that in order to install the header, it is necessary to disconnect the steering column. The column detaches with removal of a 13mm head bolt. I temporarily secured the column to the side with a nylon tylock to keep it out of the way during the install as can be seen in this picture taken from the driver’s side top:



Here's the driver's side from the top:



And here's a shot with the steering column reattached. I used some Locktite Blue to secure the bolt:



Once you've secured the headers in place with their new locknuts, the remainder is simple reassembly in reverse order of above. My experience was that the most difficult aspect of the reassembly was reconnecting the cats to the headers. You must line up the flanges on the downpipes exactly in line with the threads on the header bolt holes in order to start the torx bolts. I used new fasteners here, too, and because of the awkward angles, it was time consuming to get these lined up and started. I definitely recommend a narrow E12 torx socket so that it can fit close enough to the downpipes to achieve the right entry angle on the header bolt holes.

Once those are started, reattach the rest of the exhaust loosely, and then tighten everything back into place in proper alignment. Don't forget to reconnect the O2 connectors and reinstall the wires in their mounting clips.

Once the work on the bottom is completed, lower the car and reinstall the plug wires, coils, and air box assemblies. Make sure you don't have any extra parts lying around and you're good to go.

Initial impressions are a slightly deeper exhaust pitch at idle, and perhaps a slight loss of some torque at initial throttle, but definitely as sense of freer breathing during acceleration. I'll dyno later to get actual gains, but for now, my impression is that the headers are clearly a worthwhile upgrade for our engines.

Code3 Performance

Beautiful writeup. Nice work.

jcjmw

Thanks for the write up and for sharing. I have no doubt this post helps all those looking into headers!!!

jangy

Nice write-up. I will be doing shorty headers soon. Do you have a TB? Or a Pulley?

DFW01E55

Thanks kompressed, good work.

JamE55

Very nice write up. How long did the whole installation process take you?

waxking1

Thanks for the writeup, this is just what I needed. I also plan on doing some shorty headers soon.

spr

also curious how long it took you. I would assume it out be a bit quicker and easier as I have a lift.

psk145

what happened to the other ones you were working on?

stevebez

I have been told repeatedly that these headers will not fit a RHD setup... is the steering column arrangement in a RHD different? Is the space available differrent?

Seems pretty symetrical too me and dont see why they wont fit....

BTW that silver finish sure looks gr8... and very nice write up. I reckon my next mod is to enlarge my garage and get the car lift I always wanted!!!

dyno

BELLISSIMO !

I saved quite all shots

thanks
marco

.. now, room only for your Blue project

Zod

very nice so how are you liking them ?

MRAMG1

SUPER wite up kompressed

This is what I wish others were doing, when modding. It REALLY makes life simple when you share, WITH PICTURES!

See yeah

PS: Any before and after dynos my friend?

komp55

I wasn't really keeping track of my time, but it took longer than I anticipated because of interruptions, taking pictures and jotting down notes, being careful, and then finally getting the cats reattached. Plus, doing it as a one man job slows down the exhaust removal / iinstallation too. If you're planning for a DIY install with no distractions or interruptions, then I would allow for a minimum of six hours, possibly more if you encounter Mr. Murphy.

There's nothing exceedingly difficult or complex about doing the install; it just is a slow, methodical process, especially the R&R of the attaching nuts for the manifolds / headers. Space is tight. I was most concerned about the quality of the work instead of the time it took to do it - which is the major advantage of doing it yourself. I have no doubt I could knock out a second repetition faster since there would be no learning curve; but it's not a job I want to do again anytime soon.

OzE55

Thank-you.
Something I won't be trying!

CLS55 V8K

komp55

I know it's already been done by some inspired owners here, but I wouldn't advise anyone to do the header install without using a lift. It took several times raising and lowering the car to slide the headers into position on the studs since I was trying to be careful not to mar the coating on the headers. After I was done, I did my bows to my Rotary lift.

Yacht Master

Nice job, well done! Thanks for taking the time to record your process and share it here.

vrus

Great write-up!!!

Can I hire you to do all my installation docs? LOL.

DFW01E55

I agree Steve. Many thanks for your excellent tutorial.

I have just returned from the garage in defeat. If you don't have a lift, this is a nightmare job, in spite of what Evosport might think.

It wasn't a complete waste of time, I put the phenolics back in and that's worth, what ... 50?

SWED E55-04

I see no pics? what is wrong?

BrianS

When I did mine, https://mbworld.org/forums/w211-amg/208213-diy-header-install.html , I could definitely see it being easier with a lift but it wasn't too bad. Patience is definitely important on this one. Excellent write-up by the way.

2root4u

Bringing back this thread from the dead....very nice write-up.

Anybody care to share the torque specs for this install?

Thanks.

prodigymb

nice write up. needs to be added to the diy thread.

kurtwz

Hey, could you tell me what size torx bolts those are? I'm sure I don't have the right socket for that, so I want to make sure I buy the right one. Thanks!