Inlet manifold removal (N47 123D)

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Greg.W
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Inlet manifold removal (N47 123D)

Post by Greg.W » Mon Mar 21, 2016 11:25 pm

Hey everyone

Here's a how to on how I removed my inlet manifold. I did this as I wanted to clean it up as they are well known for gumming up, as well as checking the condition of the swirl flaps. My cam cover gasket was also leaking so this is part 1 of that procedure too.

Before I start, just bare in mind this is the way I did things, there may be other ways that are better/faster, this is just the way I saw best.

Also you attempt this at your own risk, and any damage you cause is your own fault. This is only a guide to help!

Tools required
-general socket set. I used a halfords 170 piece set. A range of normal and deep will help.
-torx bit set.
-torx sockets (they have the letter E on them eg.E10, E12 etc)
-general screw driver set
-standard tools like pliers, scraper etc
-rags
-cleaning fluid (eg degreaser)

Guide
-First remove the negative battery terminal in the boot. 10mm nut.
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-Next remove the acoustic engine cover and the front air scoop. Cover just pulls off, and 2 T20 bolts.
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-Remove the filter housing under the windscreen. 6 8mm bolts.
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-Remove the vac tube holder and the windscreen cowel. 2 8mm bolts and unplug 2 electrical plugs.
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-Remove the vac tube and alternator power cable and put to 1 side. 2 push clips and a 13mm nut on the alternator.
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-Next the 2 strut braces need to be removed. These are held in place with a central E18 bolt (under small cover) and a E14 bolt either side.
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-The rear acoustic carpet now needs removed. Remove the 2 plastic rivet popper clips and the carpet just pulls out.
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-You can start unplugging all the plugs now so we can move the wiring harness to get access to remove the manifold. I counted 6 plugs at the front, 4 from the alternator area, the 4 injector plugs and 2 from the centre. Here are also 4 bolts holding the harness in place. A small torx at the front(I used a 4.5mm socket as I didn't have an E socket that small), 2 10mm bolts attaching the harness to the inlet and a 8mm bolts at the rear left of the engine. This allows movement in the harness.

-To remove the injector plugs from the cam cover I had to remove the centre fuel rail holder to allow the plugs to slip through. This is held on with 2 E10 bolts.
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-The wiring harness can now be manipulated out the way. I used a bit of string and tied it up so it didn't get in the way.
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-Remove the inlet pipe from the inter cooler to throttle body. This is held in place by 2 spring clips that can be removed with a flat head screw driver. Can be a bit fiddly. There is also an electrical plug on this pipe to remove.

-The inlet manifold can now be removed. This is only help on with 5 10mm bolts. Loosen all 5 (they won't pull out of the holes as they are non removable and always stay attached to the manifold). When all are undone you can lift the manifold out. Be careful as you now have to reach around and under the manifold to release a few clips that cables and hoses are attached to, aswell as unplugging the throttle body plug.
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-It's out!!! You can now strip the components off it and begin cleaning. The throttle body is held on with 3 5mm Allen bolts, the pipe under the manifold is held on with 2 T20 bolts, and the swirl flap actuator is held on with 3 T30/35 bolts.
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-As you can see mine was quiet bad! My car has done just under 60k so it's worth doing if your around this or higher. I cleaned mine using degreaser, rags, brushes, screwdriver to scrape etc. Takes a while but worth it.
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-Refitting is the same as removal but in reverse of course. The tightening torque of the manifold bolts are 5nm mating, and 15nm final tightening.


And that's it! Next guide will be from here to removing the cam cover.

I hope this helps a few people. And mistakes I've made please let me know.

Thanks
Greg

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David 8
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Re: Inlet manifold removal (N47 123D)

Post by David 8 » Tue Mar 22, 2016 12:04 pm

Nice work there, how long roughly start to finish, and did you notice a difference to MPG/power/running when done ??
2009 White E81 123D, Factory Xenon's, I-Drive 313's

Greg.W
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Re: Inlet manifold removal (N47 123D)

Post by Greg.W » Tue Mar 22, 2016 3:02 pm

David 8 wrote:Nice work there, how long roughly start to finish, and did you notice a difference to MPG/power/running when done ??
I can't really say exactly how long it took me as I did the cam cover gasket as well, and had a bit of a nightmare removing 1 of the injectors! Haha.

I'd say if I was to do it now it would take roughly 2 hours to remove and refit. Then your cleaning time. So depends how thorough you are. Approx 4 hours including cleaning would be a good bet.

Again I can't really comment on how it's running as I only completed this last night, but seems fine so far. Peace of mind as well!

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David 8
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Re: Inlet manifold removal (N47 123D)

Post by David 8 » Tue Mar 22, 2016 7:09 pm

Not too bad then, on a nice day might be worth a go.

One other thought, any new seal or gaskets needed for this job ??
2009 White E81 123D, Factory Xenon's, I-Drive 313's

Greg.W
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Re: Inlet manifold removal (N47 123D)

Post by Greg.W » Tue Mar 22, 2016 11:05 pm

David 8 wrote:Not too bad then, on a nice day might be worth a go.

One other thought, any new seal or gaskets needed for this job ??
Yeh you need the inlet manifold gaskets x 4, the throttle body gasket, and the 2 o rings for the pipe. All mine looked OK apart from the o ring on the pipe that goes into the Block. This was torn slightly. I'd recommend replacing them all though.

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Re: Inlet manifold removal (N47 123D)

Post by TCR94 » Wed Jul 06, 2016 8:46 pm

Greg.W wrote:Yeh you need the inlet manifold gaskets x 4, the throttle body gasket, and the 2 o rings for the pipe. All mine looked OK apart from the o ring on the pipe that goes into the Block. This was torn slightly. I'd recommend replacing them all though.
I'm wanting to do this as I think it will give better results instead of having my engine 'carbon cleaned'.

I don't suppose you know the part numbers for the seals which are needed so I can get them ordered?
Current: M235i Work in progress...

Previous: 123D Milltek Exhaust, Performance Brakes Front & Rear, Performance Front Bumper, Carbon Rear Spoiler, Front Splitters & Strut Brace. Nexus 7 Installed.

RickyG512
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Re: Inlet manifold removal (N47 123D)

Post by RickyG512 » Fri Nov 11, 2016 12:46 pm

Hi Guys,

Thanks for the very good write up, should help me for when I plug my swirl flap rod. In the mean time I need to change my glow plugs, can you confirm I've correctly highlighted the glow plugs in the picture below please for the 2.0D N47 engine please?

Thanks,

Image

strixas
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Re: Inlet manifold removal (N47 123D)

Post by strixas » Thu Dec 01, 2016 10:45 am

Which chemical can remove black ash easy?

ianmarktuttle@gmail.com
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Re: Inlet manifold removal (N47 123D)

Post by ianmarktuttle@gmail.com » Sat Feb 25, 2017 6:10 pm

Sorry to be a pain but you mentioned inlet manifold gaskets x 4, the throttle body gasket, and the 2 o rings for the pipe. I am in the process of being these bits now but I am lost about the two o rings mentioned. What's the 2 o rings on part wise? Many thanks for your help and great article. Very handy after I discovered a leak :)

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floydroid
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Re: Inlet manifold removal (N47 123D)

Post by floydroid » Thu Apr 13, 2017 1:35 pm

Good write up.

Is it worth doing and EGR delete and swirl flap delete at the same time?

epovey
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Re: Inlet manifold removal (N47 123D)

Post by epovey » Fri Jun 02, 2017 9:13 am

Sorry to bring up an old thread but awesome write up! :o
Only two things stick out with this thread for me though. The first being that diesels don't have throttle bodies, the throttle is controlled by adjusting the fuel! What you're looking at in the picture is an anti shudder valve 😀 It basically makes for a smoother engine shut off and senses if the engine starts to run up on its own oil, usually due to turbo or piston ring failure. Just YouTube "runaway diesel" it's brilliant to watch! And secondly, yes those are glow plugs, However I'd highly advise NOT removing them if they don't need to be. There's at least one of the four that will be seized in and normally end up snapping it. Messy job as it has to be drilled and re-tapped or even helicoiled. This should only be done by a pro as you end up with metal shavings in the combustion chamber which need to be removed! Hope you find this helpful 😀

Greg.W
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Re: Inlet manifold removal (N47 123D)

Post by Greg.W » Thu Jun 08, 2017 4:01 pm

Thanks for pointing out its an anti shudder valve, I did not know that!

And sorry No those are NOT the glow plugs, those are the diesel return pipe clips. The picture below is the glow plugs. And yes I have to agree if they are working do not touch them. You will probably shear at least 1 and hate life!

Image

MSM
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Re: Inlet manifold removal (N47 123D)

Post by MSM » Mon Jun 26, 2017 3:47 pm

Hi Greg,

Thank you for sharing your excellent write up here.

Had a quick related question... Do you remember what the torque setting for the strut braces should be? I ask as they seem to be non standard bolts with a specialised purpose so they probably have a specific setting. It felt like the bolt holding them in the center to the bulkhead was a fair bit tighter than the strut tower bolts.

Regards,

M-s-m

Greg.W
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Re: Inlet manifold removal (N47 123D)

Post by Greg.W » Mon Jun 26, 2017 8:08 pm

MSM wrote:
Mon Jun 26, 2017 3:47 pm
Hi Greg,

Thank you for sharing your excellent write up here.

Had a quick related question... Do you remember what the torque setting for the strut braces should be? I ask as they seem to be non standard bolts with a specialised purpose so they probably have a specific setting. It felt like the bolt holding them in the center to the bulkhead was a fair bit tighter than the strut tower bolts.

Regards,

M-s-m
Hi mate

I can't remember the torque off hand. If you look on the website below the torque will be there, but it will be hard to find. Select your car and go to section 4 on the left hand side

http://workshop-manuals.com/bmw/

Greg

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Re: Inlet manifold removal (N47 123D)

Post by MSM » Tue Jun 27, 2017 12:03 am

Thanks Greg,

I had looked through the manual previously, but didn't work out exactly where they hid the bits I needed. For future reference, it was in the body equipment section under reinforcement, body (section 4.51.61).

States the bolts need to be replaced and the Center one has a 100nm then 90 degrees spec, so they appear to be stretch bolts. Will order new ones for mine, don't like reusing such fastenings.

M-s-m

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