Anyone have the vacuum diagram for a W202 C280 (center vent is inop)
But first, check to make sure the thin plastic vacuum line (often white), that runs across the top of the firewall and drops down near the oil filter, hasn't been pulled off where it attaches up and under the intake manifold (about 6" forward of the oil filter). It's a common thing that happens sometimes during oil changes. I found that in my case.
Thanks for any help.
But first, check to make sure the thin plastic vacuum line (often white), that runs across the top of the firewall and drops down near the oil filter, hasn't been pulled off where it attaches up and under the intake manifold (about 6" forward of the oil filter). It's a common thing that happens sometimes during oil changes. I found that in my case.
Any help will be greatly appreciated.
Thanks,
I've done a lot of reading about it. As example, this thread: http://www.mercedesshop.com/shopforu...850#post295850
But first, check to make sure the thin plastic vacuum line (often white), that runs across the top of the firewall and drops down near the oil filter, hasn't been pulled off where it attaches up and under the intake manifold (about 6" forward of the oil filter). It's a common thing that happens sometimes during oil changes. I found that in my case.
Now I also suspect a leaking vacuum line. Apparently some cars have a vacuum distribution manifold of some sort (perhaps in the RF wheel well) but before I just start tearing into things, I wanted to see a diagram of the entire vacuum system. Something similar to this from another MBZ forum: http://www.mercedesforum.com/upfiles...BF6675606E.jpg, but with info beyond just the door locks.
Thanks for any help.
http://mb.ilcats.ru/part/class/1/cco...e/029/group/80
might be able to identify your parts
* can this cause rough idle?
* where does that tube end?
please help i am desperate.
i have c280 elegance 1995, and i live in Sydney Australia.
The Best of Mercedes & AMG
* can this cause rough idle?
* where does that tube end?
please help i am desperate.
i have c280 elegance 1995, and i live in Sydney Australia.
I have a schematic somewhere, ill check tomorrow, see if i can find it.
hair line crack at the vacuum manifold vacuum manifold. also, the previous mechanic decided to swap the pins for the MAF, that is way it always faile.
superglued the crack, put the pins in their correct order and surprise surprise it works perfect. will drive it tomorrow to work with a big smile.
thanks everyone.
As numerous people have commented, I have the same problem with the center vent.
I did a system recharge and it worked fine for awhile, and thought that was the cure.
Now, it's back again, and I am just putting up with it, as it really isn't that inconvenient.
Reading all the posts for the "cure", I just want to verify that if I remove the glove box, I can see the distribution vacuum unit that is referred to, and the line that can be clamped off? If that is correct, I will pull the glove compartment this weekend and give it a shot.
Thanks
If interested i made 2 complete videos of dash removal and vacuum element fix on recir/fresh air intake. This might help you ...
Last edited by andy_1100; Nov 20, 2015 at 04:59 PM. Reason: link update
Thanks for the videos. I will watch them with great interest, as sight unseen, something eventually gets screwed up along the way.
I will post the results.
Thanks again
When you installed the new vacuum element, you needed to disconnect the passenger side air bag and remove it to get access to the pump. My question is, can the airbag removal screws not be accessed after removing the glove box and either slide it out through the glove box opening, or move it around a bit under the dash to access the pump? It would seem that the airbag is a smaller width than the the glove box, so it would seem possible, rather than pulling the whole dash out?
I just saw your located in Surrey, and that is where I lived on 64th Ave. Now, I live in Central America.
Last edited by ptcruiser; Nov 21, 2015 at 11:57 AM. Reason: Added comment
Any thoughts on what this could be?
The most obvious line by the MAF is brand new and connected. Also I blew air into the line that goes to the canister in the passenger foot well and didn't hear any leaks. Not sure if that matters.
I also got into the passenger foot well by the blower motor and slightly removed (decamped) the switchover valve to listen for leaks buy could not hear anything. Seems all is fine there since all vents work anyhow.
Since this happens to all vents what do you all think?
Seems like a common issue with many makes of cars. Not just Mercedes.
Last edited by johnnr; Mar 19, 2017 at 10:51 PM. Reason: Additional info..
I think the vacuum schematics are similar to the 202s.
I do think it's the vacuum canister (distributor) in the passenger fender. I'm taking it to the dealer because I've had no luck with Indys.
I will try and direct the dealer to look at this part first but I'm fearing their diagnosis will include parts I don't need.
So far this is what i can formulate:
1. This is counterintuitive but, the vacuum created by engine intake drops with rpm going up.
I think you have a very small leak, at engine idle the vaccum is enough to switch all deflectors to a desired position. As you start driving the vaccum drops down causing all deflectors to go to a default position.
It seems like you gonna have some tough time since the leak is not obvious. Pay attension to the line connections, on my w140 I had an end of a connector break causing my trunk soft close to operate kind of only for 50%.
From what I've read, one of main suspects when you have a leak is the manifold under the hood, there's a steel ball pressed in and the plastic manifold tends to develop a hairline crack.
Another question...do you hear your vacuum pump constantly cicling?
I am thinking since the impact is to ALL the vents, that distributor canister in the fender is the culprit, especially since the hose from the engine area by the MAF was just replaced.
It's at the dealer... Crossing my fingers here! I try to avoid the dealer but in my experience with some items, they are better equipped to handle/assess.
However, what doesn't make sense is why do ALL the vents work fine until I accelerate. Since all vents work fine until then, wouldn't that rule out anything beyond a main vacuum line (e.g. That cannister/ distributor in the passenger fender?)
Does anyone know the actual purpose of the canister/distributor in the fender?
I am told the canister is fine... so I guess their assessment of a vacuum leak within the dash, being the main culprit, is plausible.
All in all, if the only issue is me losing full blast air for a few seconds while accelerating, I'm going to leave it be. I don't want to take apart the dash, the issue isn't significant enough to warrant that. And I definitely don't want to crack or tear my dashboard!
dealer did advise, if and when I do want to replace those elements in the dash, may as well replace them all to avoid future elements that are old, to be replaced and then go back into the dash.
If one of this vacuum actuators has failed on your car you can easily find this, all you need is a vacuum pump from Harbour Freight Tools and maybe an HR of your time.
Pull every line of the manifold under your glove compartment and test for leak.
Like I said, Im really intrigued by this problem, keep this updated if you finally find the cause.
So far this is what i can formulate:
1. This is counterintuitive but, the vacuum created by engine intake drops with rpm going up.
I think you have a very small leak, at engine idle the vaccum is enough to switch all deflectors to a desired position. As you start driving the vaccum drops down causing all deflectors to go to a default position.
It seems like you gonna have some tough time since the leak is not obvious. Pay attension to the line connections, on my w140 I had an end of a connector break causing my trunk soft close to operate kind of only for 50%.
From what I've read, one of main suspects when you have a leak is the manifold under the hood, there's a steel ball pressed in and the plastic manifold tends to develop a hairline crack.
Another question...do you hear your vacuum pump constantly cicling?
a few years I asked you for the back lights (R) diagram, well not lucky with that diagram, but today I have some issue and have the same problem with the Vacuum system, I have only air for the defrost vent, and can’t close the recycling air, today I’m gonna have some time to see the problem and maybe un assembly some plastic parts to find the problem, off course up pics and videos.
ps thks for all videos
i am from Australia so its RHD and the vacuum line for RHD connects somewhere near the firewall on the right side of the car near the fuse box
can anyone help me
i am fairly new to this site and io did try a search for vacuum line w203 but only found thissite




