ruben6805

but it didnt work. i tried to crimp the lines with vise grips but didnt work. does any know how to test SVB to see if its working so i can replace it?

ruben6805

Anyone know where the Vacuum distribution block is located? i believe its in the RF wheel panel. Is this correct? please help. im not getting vacuum when i check the Switchover Valve Block.

nightmare cl600

i have these same probs with my pops 1997 c 280 sport, your thread and info have helped me greatly! so thank you all! now my pops can drive happy again!

Texas993

This was most helpful to me today. Center vents would not blow. Mynwhite vacuum line near the firewall was disconnected. Thanks!

christiank

Thanks for this posted info. The white vacuum line passing near the oil filter was disconnected from the manifold port thus causing the vacuum pump to cycle on and off and creating a P1700 code (transmission upshift delay switchover valve failure). That bit of info bypassed a tremendous amount of troubleshooting time.

hkhan1

Does anyone know what this part calls? This got detached from the white vacuum line.
Any help will be greatly appreciated.

Thanks,

andy_1100

check here:
http://mb.ilcats.ru/part/class/1/cco...e/029/group/80
might be able to identify your parts

mercedes211995

i am having issue with rough idle and it was posted somewhere to check the vacuum lines. no i detached the white tube the one coming from the inlet manifold, sucked the air out and it appeared not to hold the vacuum.

* 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.

andy_1100

Hi. Yes...a vacuum leak will cause a rough idle, but finding a vacuum leak is not that easy. My, for example, was in the rubber connector between upper and lower intake manifold. A simple check for a loose hose might be a very simple fix, if you are lucky. Best way is to use a fog/smoke machine or if you smoke buy a cheap sigar. Check youtube, there are lots of videos on vacuum leaks.
I have a schematic somewhere, ill check tomorrow, see if i can find it.

mercedes211995

FIXED 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.

ptcruiser

1998 C230
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

andy_1100

What do you mean by "system recharge"?

If interested i made 2 complete videos of dash removal and vacuum element fix on recir/fresh air intake. This might help you ...

ptcruiser

I meant that I recharged the air condition system with refrigerant.
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

ptcruiser

I watched both videos, and here is my question?
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.

johnnr

All my air directs to the defroster vents when accelerating. Then all goes back to normal. My center vents work just fine. Flap test went fine too from what i can tell. (all vents distribute air the way they should)

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.

andy_1100

Whats the car?
Find vacuum schematic for your car.
Seems its a leak in the line from engine to distribution manifold as it happens when the vacuum rises when the rpm goes up.

johnnr

It's a w208. Clk 430.

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.

andy_1100

I keep thinking what can cause this problem, im really intrigued.

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?

johnnr

Thanks for these tbiughts/ideas! The vacuum pump, if you mean the PSE in the trunk is just fine. It only works for.a little bit when using multi contour seats or unlocking various elements. It's likely not the culprit.

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.

andy_1100

Yes..lets hope it wont cost an arm and a leg..
let us know what they find

johnnr

Well, the dealer identified the switch box in the foot well area as a culprit, and that they then need to test each vacuum line because at least on is bad in the dash.

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?

johnnr

Dealer checked that canister (distribution block?) in the fender as well since I pushed the ask a little more.

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.

andy_1100

I don't want to put any doubt in your soul....I had a bad vacuum actuator that operates the fresh air intake flap, it operates in 2 directions and has 2 bellows inside. So one of the bellows had a rip in it and this was on the side that closes the flap when you turn off the climate control (press 0). So anytime I'd press 0 on the controls my vacuum pump would starts cicling every 5 sec trying to keep up the vacuum.
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.

RGPP

huotalicusC200K

hi guys i have a w203 c200k and have the grey vacuum line loose , i can see where it comes from but i cant seem to find where it connects to

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