I have an '08 C350 Sport that has the check engine light on.

They scanned the car and came up with... "Diagnosis of tumble flap 'Intake manifold' : Short circuit to ground of sensor lines / Tumble flap shafts stick in the actuated position. (P2004)

I also had a couple other places scan and they came up with the same thing. I've recently had quite a bit of work done to the car by this shop and I really like them. You know that feeling you get when you shop around and then finally talk to a guy who tells it to you straight? He has a 'no BS' attitude and literally shows me what is going on with the car. Good guy, I feel like I can trust him.

Now comes my concern. He tells me that if the tumble flaps need to be replaced so does the whole intake manifold. Seems a bit off especially because I have seen this is a common issue for W204 and they make a metal replacement just for my problem.

So other than a crack in the manifold would there be any other reason to replace it?

 

There have been quite a few instances of a P2004 discussed on here (nd elsewhere) where it turned out the issue of replacing the entire manifold was avoided by way of a kit like this: https://www.agatools.com/part/merced...FS9o7Aod5VYAbw "Mercedes-Benz Intake Manifold Lever"

For the amount it can save, it certainly is worth looking into... Good luck!

 

He could be entirely right, depending on which flap switches are malfunctioning.

The things circled in the picture are the reason I needed an entirely new manifold. I just could not source the parts for the individual components anywhere. The actuators and internal intake runner flaps are not separate item #s in EPC.

 

This is perfect, thank you. I watched out the video on the product page and he explained where you can actually see the issue. Well I checked it out and the piece was indeed broken.

If finding out something on my car is broken is great news, well, this is it.

Thank you for pointing me in the right direction.

 

The black plastic runners inside the manifold fall apart and get lodged in and under your valves and bend any that will fall in,,, destroying internals you'll see for yourself looking up on YouTube ,,,

 

Complete manifolds sell for $299.00 right
now

 

Respectable shops don't want to be responsible for exactly Whut can happen yes in most cases just the tumble flap is all you may need provided a therough inspection of the plastic runners are not loose and flapping around inside,

 

Aoooooo I just took another look ,,, the left side runner is broken I just noticed,,, yup u need a manifold that's the runner inside that's loose and will fall apart,,,,

 

Where did you find that?

 

Not really sure what you're looking at.

 

I need one too so I'll pull up the site now

 

The center tumble flap arm is available and is the most common for breaking off just like your left side but the center one is the notorious one

 

You're referring to my picture, not OP haha. I know, it happened and I fixed it this summer, the entire intake manifold did need replacing.. just posting it for reference

 

I am glad I can help....

 

Just Google "Mercedes benz parts"... And you'll get several results that would allow you to entere model year, make, and model (some may even request Transmission type, engine size....).
It will then come up with a listing of major systems on the vehicle, which you can browse through.

Oh... and as far as prices are concerned, most ill show an MSRP and an "online" price often slightly lower than MSRP but most likely lower than what your local dealer's parts department will charge fr the same part.

 

Actually, it is my understanding that none of the parts that make up the intake including (internal or external) are under seprate #s in EPC. Although there are after market manufacturers that fabricate the Actuators the connect to the rods you see coming from each canister.

Here is one that makes the replacements to the right and left levers (which I linked above)...

This guy above, makes a replacement for the center actuator piece. Although I cannt find were he has listred the part for sale. So you may have to contact him through his website.

There is one manufacturer that I know of that makes the center lever/actuator (triangular plastic piece that connects to the rod coming from the canister which you have labelled as "Swirl"), but the also make a replacement for the Rod and canister itself... Here is the kit being sold by a different outfit than URO... Here is their video:

 

Funkwagen, I've got 2 question for you about the picture below, as you seem to know quite a bit about how this thing operates.

1) When it comes to the center canister which you have labelled as "Swirl", and with regards to the rod extending from it to the center actuator... Under what conditions would the rod get pulled up and into the canister? Do you know?

2) With regards to the canister you have labelled as "LHS" and the rod that drops down from it... The reason you had to replace the whole manifold, is it simply because the rod disconnected from the part that is circled by the bottom most circle? Or is it because that other part actually came loose off of the manifold itself?

Thanks in advance fr any info you can offer!

 

1) The rod gets pulled up into the actuator at low engine RPM, I believe it starts releasing around 2.5-3k rpm. The default state for the swirl flaps is retracted, when there is no vacuum applied

2) Even if the disconnected rod was the only issue I was having, it likely would have meant a whole new manifold anyway unfortunately. There's no separate part number for the labelled actuators in EPC like you mentioned, so they can't be ordered separately which is annoying. You'd have to find a junked m272 intake manifold with working actuators and pull it off of it to replace, and as far as I can tell, finding one is basically impossible, at least in ontario here.

I don't think that part disconnects or wears quickly with normal functioning, though. The actuator labelled LHS had a leaky/torn rubber diaphragm and was causing a small vacuum leak, and I don't think it was moving the arm properly. I'm not sure which came first, the leak in the actuator or the fact that the left side variable length flaps were taking an unusual amount of force to operate. Still haven't gotten around to disassembling the whole manifold to find out, though.

I thought about ordering a kit like the one you mentioned to improve the swirl flap lever when I was replacing the whole manifold just for peace of mind, but I didn't really have the time since I needed a working car

 

Interesting you would say thaye because watching the two YouTube video I posted above, the rods basically snap on/snap off their respective actuators. Looking at the picture, it doesn'the appear to be broken or damaged, and I assumed it had just popped off... Of course a torn diaphragm would simply render it useless even if you could pop it back on.

(I guess we can call that a "actuator" as well... let's do "round actuator"...)...

Well, I asked about that particular rod because on mine, as I was inspecting the center rod and how it broke off the center actuator, I noticed that while the rod was still connected to that round actuator, the round actuator itself had slipped/snapped off the shafts where it belongs... I snapped it back on and it stuck... So.considering that it too is made up of the same degradable plastic material, and in fact it is in direct contact with the engine block(whereas the other style actuators are floating nearby), I would venture a guess that it too may be worn out and it will likely take very little for it to pop off again.

I am only guessing about the following but I can only assume that one (or more) of the canisters on mine has a torn diaphragm because prior to removing the vacuum pump (to get a little better view of the rods/actuators) I could hear this discernable hissing noise, and spraying carb cleaner in that general area just under the canisters would cause the engine to go into convulsions (rough idle).

I too am having an issue with taking it all apart with this being my only car at this time... And to make matters worse, I emailed the European Motor Works yesterday (link in my last post) asking him about the center actuator he sells, how much it is and how long it might take in transit... While I realize its only been one day, I'm not too happy about having received nothing in response as of yet!!!

I'll let you know how I make out with a used/junked intake manifold... (I'm in the Los Angeles metro area)...

Thanks for the super quick response and all your input.... I appreciate it.

 

Those actuators look amazingly similar to the vacuum door lock actuators on a W210...and those have the diaphragms available through several aftermarket suppliers. FWIW.

 

Yeah, I thought it'd just pop back on and that'd be it. I actually did that at first. I knew that'd be too easy a fix, though, and unsurprisingly it came back off within about 30 minutes of driving.. They're supposed to snap together, but it just sort of loosely connected and wasn't fastened well at all. Must have worn out, very strange.

Sounds like you definitely have a vacuum leak coming from somewhere, you should check these connections circled in red before anything (they'll be connected to vacuum tubing, of course) to see if they're loose or improperly sealed. Check to see if the plastic connections wiggle at all as well, they shouldn't - if they do, that'll probably the source of the leak

 

Thanks Funkwagen for the additional input...

I should probably mention that while this issue usually causes a CEL with OBD-II codes P2004, P2005, P2006... IN my case, I have had none of those come up. Instead, the codes I have been reading, clearing only to have them re-appear almost immediately are ALL seven misfire codes (Yes seven = six for each cylinder + 1 P0300 which reads "Random/Multiple Cylinder Misfire Detected").

In addition, I am also getting:

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

P0430 Catalyst System Efficiency Below Threshold (Bank 2)

As well as:

P0171 System Too Lean (Bank 1)

P0174 SYstem Too Lean (Bank 2)

And here I thought that the OBD-11 system was supposed to simplify diagnosis... The combination of codes above actually imply a possibility of for approximately 22 possible causes...

 

Sounds like you have a vacuum leak significant enough that the engine can never reach an air-fuel ratio of 14.7 or below even with fuel trim adjustments, too much un-metered air is entering the intake and causing it to run lean/misfire by altering the air/fuel ratio. The catalyst system is being thrown off by this causing those errors as well. You catalytic converters are probably running quite hot while you're running lean, which isn't good in the long run - running lean can damage them..

You should definitely try to find the source of the vacuum leak as soon as possible and fix it, the extra heat from running lean all the time can be pretty harmful. You may have to remove the intake manifold entirely to inspect everything, and you'll need replacement intake manifold gaskets for when you reinstall it. Best of luck!

 

Thanks again for your great insight as well as the extremely helpful tips... I've got a set of gaskets on order already... those should be here tomorrow, and I also believe I have gotten really lucky to have found a 2011 C300 intake manifold as a replacement (I've confirmed proper fitment through EPC). That, I will inspect and hopefully pick up later on this afternoon. If not, a local (independent) parts store has assured me he can get me the OEM (made by Pierburg) with 24 hours notice for the Amazon price match.

And so I've cancelled my plans for the weekend as it appears I will be up to my ears in elbow grease... I just hope that when all is said and done, that I don't have any extra parts... Hate when that happens!!!

Since you are a few steps ahead of me in this process, can you think of any special tools that are needed to remove and replace the intake manifold? I've already got a set of regular and deep sockets, extensions, as well as a set of Torx bits and a set of E-Torx sockets as well... Anything else?

Thanks again.

 

Hope I'm not too late responding! You should be fine with the tools you have though, just take your time, I labelled most of the sensor connectors so I knew what went where when I reinstalled everything. You might want an extra pair of helping hands for when you reinstall the manifold, I had a friend help me by pulling back the wiring harness when reinserting the manifold, made it a lot easier. Good luck!