Preamble
- This post is for information only. Despite my best efforts, I make no claims or warranties regarding the accuracy of this DIY. Your vehicle, its parts, systems, and torque specifications may differ from what is detailed below. You assume all risks associated with working on your own vehicle, and do not hold me liable for any damages. Having this work done by a qualified mechanic is recommended.

Why did I decide to perform this procedure on my vehicle?
- Preventive maintenance.
- Odometer: 104,000 kms.

Part List/consumables
- Fuel Filter (1x) c/w condesation sensor ------------------------ A 642 090 60 52
- 5/8 inch Stainless Steel Clamps (2x) OR the clamps below
- 13.5 mm CLIC hose clamp (1x) --------------------------------- A 00 499 720 90
- 15.0 mm CLIC hose clamp (1x) --------------------------------- A 00 699 718 90

Special Tools
- (Optional) Mercedes CLIC hose clamp tool 171 589 00 37 00. Only if you decide to use OEM clamps.

Before you begin the work
- Open and close the gas tank filler cap to help relieve any pressure currently in the system.

Air/Acoustic System Removal


- Disconnect engine Cover [700] from air duct [600]. Pull up on engine cover to remove.
- Remove intake Y-pipe [85] downstream of filter housings:
------ Disconnect electrical connections for each MAF sensor [915], one per side.
------ Unclip connections to air filter housings [400, 410] by two clips per side.
------ Loosen clamp [110] connection.
------ Pull intake Y-pipe [85] gently towards front of vehicle to remove from turbocharger.
------ Carefully disconnect [150] from intake Y-pipe during removal.
- Remove charge air duct [80].
------ Remove bolt [130] from charge air duct to engine.
------ Remove bolt [430] and bracket [420] from charge air duct to silencer [400].
------ (optional) Remove bolts [460] and [440] to allow silencer [400] to be easily maneuvered.
------ Slide the charge air duct [80] towards the front of the vehicle to remove from turbocharger.
------ Exercise caution not to lose or damage the o-rings [83] and [410].

Fuel System Removal

- Disconnect electrical connection to fuel filter condensation sensor [6].
- Detach fuel hoses [2] from fuel filter by first disconnecting clamps [3].
- Loosen 5 mm hex screw [5] on fuel filter mounting collar. Lift fuel filter [4] upwards to remove.
- (optional method) remove three bolts from fuel filter mounting collar, and lift fuel filter complete with mounting collar upwards to remove.
- (optional method) remove mounting collar from fuel filter.

Reinstall fuel system
- (optional method) reinstall mounting collar to new fuel filter [4].
- (optional method) reinstall fuel filter complete with mounting collar with three bolts (not shown).
- Reinstall fuel filter [4] and tighten 5 mm hex screw [5] on mounting collar.
- Reattach fuel hoses [2] to new fuel filter using OEM CLIC clamps [3], or 5/8 inch stainless steel hose clamps.
- Reconnect electrical connection to fuel filter condensation sensor.

Reinstall Air/Acoustic System
- Reinstall charge air duct [80].
------ Lubricate o-ring [410] with fresh oil and carefully press charge air duct back onto silencer [400].
------ Reinstall bracket [420] and bolt [430] to affix charge air duct to silencer.
------ Lubricate o-ring [83] with fresh oil and carefully press charge air duct back onto turbocharger.
------ Reinstall bolts [460] and [440] to affix silencer to engine.
------ Reinstall bolt [130] to affix charge air duct to engine.
- Reinstall intake Y-pipe [85] downstream of filter housings:
------ Carefully reconnect [150] onto intake Y-pipe [85].
------ Push Y-pipe [85] gently rearward onto turbocharger.
------ Reinstall clamp [110] connection to turbocharger compressor inlet.
------ Reconnect to air filter housings [400, 410] by two clips per side. Exercise caution to align mating face of both parts to ensure an air tight and aligned connection via gasket [100].
------ Reconnect electrical connections to each MAF sensor [915], one per side.
- Reinstall engine Cover [700] by placing/pushing down on standoffs, and reconnect tor air duct [600].

Initial Start-Up
- Turn the key to 2nd position (run) position and wait 5-10 seconds for fuel system to prime.
- Repeat above several times to get as much fuel circulated through the filter as possible.
- Start vehicle. There may be a idle hesitation if entrapped air is still being evacuated from the system.

Conclusion
- No perceivable changes. No error codes.

Please notify me if you find any errors, discrepancies, or tips/tricks which I should add to this tutorial.

 

Nice write up. Did mine a few weeks back, it's a pretty basic change out but such a silly design. Also should mention to protect the turbo intake, or any air ducts, from foreign dirt during the process. I use a clean rag to gently pop into the openings (in case you drop a screw in!). It's also easy to forget to push in the PCV vent hose under the intake to the turbo, and if left out would allow unfiltered (and un-metered) air to enter the system.

 

I appreciate your feedback. I agree that care should be taken to protect exposed parts from debris. In addition to lint-free cloth and towels, taping-over exposed openings can be helpful.
Regarding the PVC connection to the y-pipe; that step had been identified within the DIY. Refer to below.

As a side note; while the Y-pipe is removed, it's a good opportunity to check the turbocharger shaft for play.

 

I tried to replace fuel filter last week. Pretty much everything is straightforward, although a lot of connections/pieces to remove. Anyway when I got to the "Remove Charge Air Duct" [80}, I encountered the following:
--- just in front of the engine where the belt is running there is a plastic cover. There are 2 bolts on top holding it. I removed the 2 bolts holding the plastic cover, but there still appears to be something holding it in place. Either midway down or the bottom?, so I wasn’t able to get it out. Any idea what is holding in place after removal of the top bolts?

Here is a pic of the area I am having trouble with the two top bolts circled:

 

Jpkcpa, this configuration appears different from my 2014 GL350. What is the year/chassis/model of your vehicle?

 

2013 GL 350 X166

 

Based on Jpkcpa's VIN number, his vehicle is equipped with option code "468 ACTIVE DRIVING STABILITY (ARS)" or Active Roll Stabilization.

The WIS does mention that vehicles equipped with this option code will have an "Impact Plate" which must be removed ahead of the charge air hose/pipe. I feel that this may be the plastic cover you are currently having issues with.


Comparing your photo to the photo of my engine bay, it is possible that aside from the two (2) bolts you've already removed, the only remaining connection point is a grommet at the base of the impact plate. If possible, try pulling upwards to remove the impact plate from this grommet (similar to removing either the left or right side air filter housings). Also don't forget to detach your two (2) hose supports from the impact plate.


Hope that works for you. If not, please share your results so we can figure this out.

 

That is indeed the plate. I located the grommet but it is securely in place. I used a good bit of force to pull up but it wouldn’t release. I then climbed underneath and located it. It does appear to be a plastic post through a rubber bushing. However, it looks like it has a larger diameter head on it than the hole in the bushing. I tried to push it up from underneath, but it just looks like it’s too big. I’m going to try again on Thursday to see if I have better success.

 

I'm sure you've figured it out by now but there is a plastic nipple that sticks through that rubber grommet. It's a bugger to pull back though when removing it. I lubed mine with some oil which made it a little easier but it will come (alone with some twisting and pulling). I really thought I was going to break it.

WJ

 

Thanks for the feedback. I ended up needing to schedule service for A/C and oil cooler (again!) and spoke to the service tech. He basically said the same. They are very difficult to remove but only require that you pull up. Thanks for the lube advice. Will use that next time. They agreed to change out for no labor charge on this one as long as they had to pull it out anyway. But DIY will allow me to change more frequently than the 40k mile recommendation.