I have decided to clean out the intake valves mechanically using a walnut blaster. My GLE43 AMG has over 143K miles and I have noticed pretty bad hesitation when gently accelerating, while heavy acceleration seems unaffected - although I imagine there's some performance loss. I also began noticing a rough idle; however, upon using an intake and turbo cleaner from CRC I did notice that the rough idle subsided. I have also noted more recently that the PCV breather line is somewhere leaking - I can hear now a slight whistle and it appears to be coming from under the intake manifold. I have thus decided to take on the challenge of walnut blasting the intake valves as I understand this to be a GDI engine and despite the built in oil catch system it still develops a carbon buildup - and I have to remove the intake manifold just to get to the PCV / crankcase breather line anyway. I think I have evidence of the carbon buildup as using CRC cleaner did help with some improvements to the rough idle and acceleration. I have already changed the sparks only 6 months ago. Getting to the intake manifold is not exactly easy - and it appears at least one sensor wire/line is tucked under a bracket for the pulleys - and that's where I am currently stuck. Should I just cut the line and solder the three wires back together? Or remove the belt and the pulley altogether? I assume the latter.... I also managed to snap/break off the release mechanism on the ECM... so it's not coming off - going to just tie it off to the side. I will update this post with the progress and pictures and please wish me luck. Some other concerns/thoughts... I will need to turn the engine ... do I need to remove the air cooler to do so? Lastly, has anyone tried methanol/water kits on this car? Bit random but I saw another post where that would supposedly help avoid the issue of carbon buildup altogether.. while also adding a benefit of performance gains - curious.

Getting all the sensors disconnected. So many sensors... Oil filter removed... Air Filters removed... still one wire is stuck...

Oil leak supposedly from magnet cam adjusters. Seems about right given there is no oil above - only below...

This wire is trapped behind a pulley bracket - not cool.

Bought the following from Amazon:
I also bought walnut shells but didn't need to - it comes with a lot!
okay honestly after reviewing the full Crankcase Ventilation System for this car... this is likely unnecessary but... we'll see if it can catch can...oil rather.
VEVOR Articulating Borescope Camera with Light, Two-Way Articulated Endoscope Inspection Camera with 6.4mm Tiny Lens, 5" IPS 1080P HD Screen, 8X Zoom, 8 LED Light Snake Cameras for Auto, Plumbing
hoping to scope the cylinders too while I'm in there and also for getting better view of the valves.

Bought the following from FCP Euro:
Mercedes M276 Crankcase Ventilation System Kit KIT-2760107111 - Likely more than I need - as I really just needed to replace the one line... but thought I would get the full kit to have on hand to replace additional components as needed.
Mercedes Intake Manifold Gasket (3 of ELR-582090 and 3 of ELR-582110(6 in total)) - This isn't expensive and figure I might as well replace them while in there
Mercedes Air Filter Set KIT-2760940504 - while we're in there - the old ones didn't look great... nor horrible
Mercedes Oil Change Kit 5W-40 KIT-523081M - I figure I had to take out the oil filter to access things so why not do another oil change... and it has been 6 months....
CERA TEC Engine Oil Additive (300ml Can) MOL-LM20002 - I like the Liqui Moly additives
Mercedes Camshaft Solenoid Kit KIT-2761560790KT - I bought this sometime ago but never installed - it appears the old ones were leaking slightly and the dealership had recommended replacing them.

Maybe I have been watching too many LegitStreetCars videos but thinking/hoping I can take this one on as well.

 

Very detailed! Thanks OP : )

 

Just a few updates while I'm on here...
I likely should have simply bought 4 of these rather than buying the whole solenoid kit - as its really just the rubber seals that had worn out. The old ones were squished and you can actually see where oil was getting around them.
Mercedes Camshaft Solenoid O-Ring - Reinz 0169975045

Meanwhile - upon viewing linked from this post, https://mbworld.org/forums/e-class-w...ml#post7651223 - I have decided its in my best interest to replace the other components in the crankcase ventilation system - so I'm glad I bought the full kit in this case. Also going to go for the oil catch can as an added preventative measure.

I'm also going to get the MAF Sensor cleaner and clean that puppy up while I'm at it.

Meanwhile I was able to get the intake manifold removed and got a few photos.


Bought the entire kit but really just needed to replace the rubber gaskets/seals. Could have saved some $$$.

These gaskets look okay but replacing just the same- I noticed a bit of oil in the intake manifold but nothing too significant.

Intake Manifold Removed and to the side..

with intake manifold removed

I honestly was hoping to see worse but this is one of the cleaner sides/ports.

 

And I got so focused on the intake I nearly forgot about why I started this - a broken PCV line...
Here's where the crack was in the line:

small hole/crack in the middle. The replacement includes both lines that you see in the photo.

This is where it was in relation to the rest of the engine - e.g. it was under the intake manifold.


Also another question I have is - where do I insert the oil catch can? Hope to find the answer to this- meanwhile... the question on removing that last wire... heck with it ... its still there but I'm able to access the ports, etc. from what I can see so hopefully all good. Think I'm going to do some cleaning/vacuuming before getting much further.

 

Thanks for sharing this. At my age I wouldn't attempt to do anything like this anymore. It will be interesting how it all turns out performance wise when your done.

 

Thanks! I will be happy to get it back together at this point - although really considering that water/methanol injection kit for fun...

So does any one have a suggestion for removing this? I don't want to break the center component that is piped to the cover for the oil drip pan as I have realized that access to the oil drip pan near the passenger firewall - is not easily accessible. I can't even get an angle for my camera to see it.


Just trying to take the connection in front off. Not easy. I finally got the top smaller hose removed - but I can't figure out the mechanism on the larger one - and or it is fused together.. any ideas?

This is what the new one looks like- I got the orange/red one out - the green one is stuck on the old module - taking out the component is extra difficult.

At this point I have broken off all but the last bit... hoping I can perform a bit more surgery and get it out successfully... fun times.

 

Having been through a carbon clean with my previous Audi RS5 at around 60k miles, your valves don't look bad at all at 143k miles. I wouldn't have too high hopes of seeing a lot of performance improvements. I definitely noticed it in the RS5, but this is how the valves looked after 60k. The shop I brought it to used the solvent and scraping out the buildup approach. Walnut blasting is messy.

 

Would you say frequent Italian tune-up might had helped?

 

I redlined the crap out of it. With an 8500 rpm redline you gotta have to let it sing . The first and second generation direct injection engines basically had no mitigation for the carbon build up. This wasn't as bad as what people saw on the B7 RS4 and other first generation DI engines. For the RS5 engine, Audi increased the oil temperature, which is one mitigation that helps somewhat with the build up, but it wasn't enough. Having oil separators and catch cans that get the oil out of the intake air is pretty much the only mitigation, or have both port and direct injection, so the valves still get periodically washed. Combustion engines are getting ever more complicated and creating new issues as manufacturers have to find creative ways to meet emissions regulations. The internal combustion engine is getting killed by a thousand cuts.

 

I was curious because that is how we drive and in the case of a forum member with a M276 so the V6 that had 150K miles, the carbon deposits was very minimal for the mileage and they did tell me they reline often.

 

Well some quick progress to note - but not finished yet!
The walnut blaster apparatus is basically a shop vacuum cleaner with an attachment for the high pressure air line - so it vacuums the walnut shells while it blasts them - recycling them around and around. Not bad, but my pancake compressor can't really keep up well so it's taking more time than it should! Nice thing is - it isn't messy in this case. I thought I was going to need to 3D print an attachment... and honestly I kinda hoped I did as any excuse to use my 3d printers in function is welcomed. Alas - the machine comes with an array of silicone attachments that fit snugly within the port - allowing the vacuum and walnut blasting simultaneously and within a closed circuit... well at least for the walnut shells. I actually could see chunks of black carbon that it had vacuumed up while blasting them free.
I finally got the breather hose loose from the plastic housing... in pieces. I used a 90 degree angled flat head screwdriver to help pry the bottom parts where it snaps in place - then used spark plug wire pullers to finagle it free. Surgery...
I have some nice photos of the valves before and after that I will post soon... I need to finish the 5 ports that are available.. then turn the engine for the last... while the car is in neutral (but its in park and battery is detached... so that's something I will shortly figure out)....
I ensured the front covers were in place before I started shooting walnut shells everywhere.
TBH - the machine works great imo. There were maybe 5 little bits of walnut shells that got out... the rest just gets sucked up... cycled around... There is some dust that remains and needs to be wiped out and blasted with pressurized air alone. The machine has a valve so you can dial the walnut shells on or off and a varying level.
I did spray them down with intake cleaner anyway. I'm also going to dial up the psi to 90-100... at 60-80 it has been okay but I think it needs more.


Here you can see the vacuum line attachments and the pressurized gun with the lines for compressed air and walnuts built in. What you don't see is an inlet port for the compressed air in back.


Walnut De-Carbon Cleaner... e.g. shop vac with attachment for external air pressure .. supplied by my pancake compressor which is trying to catch up... Nice thing over your hobby lobby setup is that this constantly recycles the walnut shells - so no reloading necessary.

components of the walnut shell cleaner - the big cotton section is just really a filter - walnuts stay on one side - suction on the other.... pressure is attached in the back via a pancake compressor.

Add the walnut shells to the lower chamber. pancake compressor supplies the compressed air via yellow line.

Here you can see the Yellow Silicone attachment that fits within the port nicely. Then attach the vacuum accessory that has a hole in it for the walnut shell blaster - which is supplied by compressed air and a larger white/clear line for the walnut shells.

I used these for the covers and mag cam adjusters' o rings...

Font valve/cam cover screws after a quick clean. I can see the blue paint on the screws again.

New magnetic cam adjusters installed after cleaning the covers. I want to be able to see if they leak and hard to tell if they are covered in old oil...

Used a plastic razor to clean the old gasket material.

Installed. The procedure for the gasket maker is to hand tighten the screws - wait an hour - then come back and tighten to spec. Which in this case is not a lot - okay I can look it up but I hand tightened them gently. As they are magnesium covers I believe. Tighten like you would a tire - always tightening bit by bit and going over and across... not all at once on any one bolt.

I call this - winning. I got it off but it wasn't pretty.

 

So I will share a few more photos from the final clean here soon but this is on its way!


needle nose pliers are also a hose guide/holder while an old lamp holder is keeping the vacuum line tidy

I couldn't reach certain bits and started thinking ... what can brush in hard to reach spaces... TOOTHBRUSH! but it was still too wide so I cut it in half. BUT - it wasn't strong enough to get some carbon baked on near the top of the valves.. so I thought ... what would a dental hygienist do? And I found my dental pick from Ace Hardware and was able to get the last little bit of carbon buildup that sits near the top of the valves. I did this while using the camera and screen to aim perfect. I kept thinking about a dental cleaning.

used a shop rag to wipe up until here after spraying with intake cleaner - and soaking up what I could with a paper towel.....

first blast of walnut shells... barely starts to clean the left valve.... leaving shells embedded in the oil.

another 30 seconds later - this is the last port on the right and not as easy to access. getting closer.

much better but not complete. Meanwhile the camera date/time is fixed/removed moving forward.

 

Progress!

 

Two steps forward ... and one giant leap back...

aww nuts - the intake valves on this port were just barely open - despite appearing closed - I knew better but thought I was getting lucky. Now I have a piston full of nuts... I bought a small tube and vacuum hose accessories... the nuts were too oily and sticky and wouldn't budge with the vacuum alone... and now I am pouring fuel into the intake port while vacuuming it out the spark plug hole... basically just port injection at this point right? I put a bunch of walnut shells in the vacuum first so it soaks up the fuel. Then quickly emptied the vacuum and got away from the fumes..
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Now that you've added extra texture to the head and valve stems how long before massive carbon buildup do ya think ?

 

Oh it's mostly out of there at this point. I left my sd card in the computer so no good photos yet but I was able to vacuum while blasting air and knock loose most all the walnut shells. I read a reddit post where someone did the same and they were told it's nothing to worry about but to change the oil as likely some shells made it around but otherwise..."send it". The shells should burn off and soft enough not to scratch the metal. Meanwhile lifted the car and unscrewed three bolts to loosen the air cooler so that I could access the 27mm bolt on the crankshaft pulley . The cylinder looks good. One more to go after turning the engine just a bit more. Already did a bit to further open the intake valves to vacuum the rest of those shells out of the last cylinder on the right.

 

Well at this point I have had the car back together and the intake valves are clean and its running. It did not start initially and I actually had to change all the spark plug boots and changed the sparks at the same time. I destroyed a couple boots just taking them off... one fell into pieces... thinking it didn't start initially because the reused boots were broken..












But I have a problem with low turbo 1 boost and it accelerates from 0-60 in about 11 seconds... . I realized that this was occurring AFTER I used the CRC cleaner as well and before I actually started the walnut blasting - as the hesitation on idle went away - but then I had some loss of horsepower and assumed I needed to further clean the intake manifold.... and also I had the crack in the crank case breather hose... perhaps there's still a crack or something is not tight.... or perhaps there is mechanical damage to the turbo from carbon fouling up the turbine?... none sure. I'm hoping its simply the sensor that got CRC cleaner on it ... which you're supposed to avoid... I've ordered the sensor from FCP Euro and it should arrive in a week. So I'm thinking the issue is either, 1) manifold sensor is broken, 2) still a crack in the breather hose/PCV system, 3) one or both of the turbos is caput from carbon fouling it up?... maybe... OR maybe the exhaust system has a restriction? IF there were walnuts in there then I would have expected them to burn off by now....
hoping its the $20 sensor... thoughts? Should I just drop the exhaust and check exhaust turbine... or just see if the intake turbine spins freely?... if its the PCV I'm going to be annoyed.

 

It’s unlikely with the small amount of carbon you had on your valves that you have any issues with carbon on your turbos. Since you are thinking, this was in conjunction with use of CRC, it is likely any sensor that got covered because as you stated the directions say to make sure you don’t spray any sensors with an intake cleaner. I don’t know that engine extremely well, but have you changed any turbo check valves or boost controllers? Or monitored on diagnostics?

 

I totally agree with you and I actually took a look at the turbos while running the engine and they are spinning beautifully. The only mechanical issue I could imagine at this point would be restrictions in the exhaust; however... that too seems unlikely.
I do think I messed up the sensor in the intake manifold - I have ordered a new one but its taking longer than I expected to arrive. Maybe I should have shelled out extra for one at Mercedes after all... nope - just called Mercedes of Austin... its $250+ which is almost hilarious but that's truly a ripoff. The Bosch one is less than $20 online albeit the faster shipping was more expensive ($50) - and that's why I'm waiting on it for another week I think. Meanwhile driving my old '09 ML 63 and it's a blast... that V8 is so mean...
BTW - I watched F1 over the weekend at a 4DX theatre - pretty good! Wish they had a note at the end... "DRIVE SAFE"... most everyone left the theatre driving like a bat out of hell - and two imports wrecked and shutdown the highway just after....
Meanwhile I was driving the GLE at the time and I wasn't going anywhere fast with this sensor issue!
Quick edit - I did run some diagnostics and I am no longer getting any error codes - not even low boost warning; however it still drives sooo slooow. I read the intake manifold pressure and its coming back with below ambient pressure the whole time... hoping that's incorrect!
Is there a way to test the sensor independently ... in my garage... like... maybe I can check the ..... ... yea not sure what. resistance?

 

Ends up I had the wrong part on order!
There are three different air pressure sensors... one on each air filter box... and one on the intake manifold itself.

I had ordered:
Mercedes Absolute Pressure Sensor - Bosch 0071530528 (there are two of these and they go on the air filter box)
however, I really should have ordered:
Mercedes Manifold Absolute Pressure Sensor - Genuine Mercedes 0009055906
Luckily I found the part at Autozone and its being shipped to my home tomorrow, $50... I could have picked it up today from a nearby store - or paid 5X and gone to Mercedes...
Santech MAP Sensor MP0179 Part #MP0179 SKU #1071452

 

You need to use a computer that can show you requested vs actual values. As the owner of two benzs, you really should invest in a xentry setup. Also, many will say not to use aftermarket sensors. If cost is an issue, find the oe manufacturer such as Denso or Bosch.

 

Several good points and I'll cast another... I bought the wrong part again... by the time I've bought all the wrong parts I could have bought the $250 overpriced part from MB - actually what's strange is the part number on my car... shows as not compatible when I go to buy it online. And agreed - I was going for the Bosch replacement initially...
Xentry - would that help better locate the issue? Seems if it was sensor related that I would be getting some engine warning light but no such luck.
I downloaded the service and parts manual previously but had to reinstall the windows image and didn't wait to order what I thought was the correct part from Autozone.
Part Number Part Name Price Quantity Total 009-153-33-28 Pressure Gauge Converter $52.00 (here's to the third attempt... )

 

Well - pretty sure its not a sensor. Smoke test below. Good news - problem found...

Smoke test reveals a sensor may be less of an issue and a missing seal or improper manifold seating is to blame... shall find out soon. Clearly I should have done a smoke test prior to ordering sensors... so many sensors...

 

So a bit of an update on this saga ... The manifold was reseated and gaskets repositioned - no more leak from the manifold; however, its still moving slow and I'm not getting much power. It drives though - and no engine lights - but it is not quick. From the ECU: I had a historic P029909 code - "The boost pressure of turbocharger 1 is too low, There is a component fault."... and more recently got a current - "The boost pressure of turbocharger 1 is too low". But which one is turbocharger 1 and how do it know? There is only the pressure sensors above and below the throttle body on the intercooler and intake manifold respectively from what I can tell - so how would it know which turbo has low boost pressure?!

And I am now focusing on the turbos and specifically the wastegate actuators and the boost pressure solenoid. I'm going to do a vacuum test and go from there ... watched this video and now I am trying to actually diagnose the issue rather than whack a mole replacing parts... ...although I'm a lot better at buying parts tbh. The video is of course for a different model W212 M274...

- So I hooked up a hand vacuum to the air line that connects both turbo boost pressure control flaps by disconnecting it first from the boost pressure solenoid. It held a vacuum and I could see both turbos' had the control flaps' connecting bars move. Although the one on the passenger side didn't appear to move as much - hard to tell. But the vacuum held - and they both moved. I think that's a pass?
- The other end has a vacuum when the car is running ... I think that's another pass...
- and it seems the boost pressure solenoid/transducer is working as designed as plugging it in and unplugging it shows the control flaps moving while at idle.. .I think that's also a pass?
Not sure how to test the actuators - maybe one or both are bad?
Or maybe there's a restriction in the catalytic converter... because I'm not sure what else the issue could be. Any thoughts?!

Photo taken with engine off - it showed a strong vacuum when running though.

 

Sorry for your issues, but It looks you're being very thorough and that you'll zero in on the problem.

It must be fun to go through those diagnostics. If you have the time, that is.