Where does this vacuum canister connect to?

[Springs37923]

Hi e36 friends.. m52 owners in specific who know their engine bays.. I recently had my throttle body off and all the stuff on that side of the motor (MAF, ducts, air box, etc).. I saw a vacuum canister just laying suspended in the rear of the engine bay close to the fire wall.. One side of it has a vacuum hose that runs all the way to an under the fuse box (long hose), and then the other side has another very short vacuum hose and it wasn't connected to anything.. I can't find a nipple that it would go onto.. Below is a pic of the canister just pulled up over the intake tube... Does anyone have a pic of where the short hose goes?? I just put a small bolt in so it's not left open while unplugged.


Thanks in advance for any help!

[gc325is]

try entering the part number in realoem.com to find what it is and maybe where it goes.

[Springs37923]

try entering the part number in realoem.com to find what it is and maybe where it goes.

Well thanks, but I was hoping for a MUCH more SPECIFIC answer..

[shoman24v]

Somewhere in the intake?

[Springs37923]

Somewhere in the intake?

I dont think so. When I was at the local BMW dealership buying some parts, I asked a tech and he said it connects into some sort of emissions switch.. He gave me the general area of where to look for the switch(it obviously has a nipple to plug the hose onto)... I just havent had the time to disassemble everything again and look for it and was hoping to get a second opinion from someone who had dealt with this canister before.. Well.. no luck so far..

[Ronnaferd]

It may be one of the hoses that go into the bottom of the intake manifold...

[dRock13]

is that the charcoal canister? you don't need itttt. :P

[MParallel]

Yes that's the charcoal canister.

[DJCarbine]

If its an OBDII 1996 E36, that is the vacuum canister for the muffler flap. One end runs to a tee in the vacuum system, the other end runs to a fitting on the underhood fuse box that goes to the rear of the car.

The purpose of the vacuum canister is to store vacuum so the muffler is in "quiet" mode when you start the car in the morning.

The intake manifold has 2 small and 1 large vacuum ports under it near the IAT. The large port goes to a solenoid bolted to your drivers side shock tower, which then runs to the evap tank in the rear of the car. One small port runs to the fuel pressure regulator, and the other runs to a tee which splits the vacuum signal between the muffler flap and the secondary air pump

This is on an OBDII 328i, if you have an OBDI then disreguard the above

[MParallel]

If its an OBDII 1996 E36, that is the vacuum canister for the muffler flap....

Talking about throwing sand in someones face.

That has nothing to do with the exhaust flap, at all.

Where in the world did you get this info from.

[strad]

Well, I don't know where the charcoal canister is on a convertible, but I know for sure that it is in the spare tire well on a coupe. To the op: I'd suggest looking there (in the spare tire well). If the charcoal canister isn't there, than I would suspect that what you found in the front is the charcoal canister, b/c that's about what it would look like.

[MParallel]

Well, I don't know where the charcoal canister is on a convertible, but I know for sure that it is in the spare tire well on a coupe. To the op: I'd suggest looking there (in the spare tire well). If the charcoal canister isn't there, than I would suspect that what you found in the front is the charcoal canister, b/c that's about what it would look like.

If you check the ETK, the boot (trunk) mounted one is not listed a non-vert specific, but used on Sedans, Coupe's and Verts.

[flyfishvt]

I have OBDI and its in the engine bay by the airbox.

[DJCarbine]

Talking about throwing sand in someones face.

That has nothing to do with the exhaust flap, at all.

Where in the world did you get this info from.

I had the exact same vacuum canister, and it ran to my muffler after I traced the lines. It was under the intake manifold, it HAD a mount but it was broken, so it was just laying near the steering joint near the firewall.

The vacuum tank is part # 18101740207
From the size of the intake runners it looks like he has an OBDII vehicle, and that looks suspiciously like the vacuum tank in question

Testing this theory is simple, take the short end of the vacuum line on the tank and apply 15-20" in/hg of vacuum with a pump. Remove the pump, then after a few seconds remove the vacuum line from the other side of the canister. It should hiss, proving the vacuum canister was holding vacuum.

The other way of testing it is to hit it with a hammer and see whats inside.

[gc325is]

If the part is # 18101740207 as DJCarbine said, RealmOEM has a diagram to what part it connects to, An Electric Valve. Then it goes to the muffler.

http://www.realoem.com/bmw/showparts...18&fg=20&hl=18


I believe there is a flap in the muffler that opens under hard load to reduce back pressure, but it adds more noise.

[bmwbob89]

Yikes! it's not the charcoal canister. It is a vacuum reservoir for the muffler flap. The flap is a noise reducer and is closed at idle. There should be a little solenoid that the hose goes to that operates the flap. Keep looking and you will find it.

[richardodn]

Looking at my 98 328iC, that does indeed look like the vacuum cannister for the muffler flap. One vacuum line runs to the fusebox which I would assume is where the valve is. I'm still trying to see where the other end connects to manifold vacuum. It mounts parallel to and below the starter.

On the underside of the intake manifold between runners 1 and 2 is a small device. Mine has 2 vacuum lines connected to it; one with a blue stripe and one with a white stripe. I think it is the one with the white stripe but I can't be absolutely sure without taking some stuff apart.

[DJCarbine]

Looking at my 98 328iC, that does indeed look like the vacuum cannister for the muffler flap. One vacuum line runs to the fusebox which I would assume is where the valve is. I'm still trying to see where the other end connects to manifold vacuum. It mounts parallel to and below the starter.

On the underside of the intake manifold between runners 1 and 2 is a small device. Mine has 2 vacuum lines connected to it; one with a blue stripe and one with a white stripe. I think it is the one with the white stripe but I can't be absolutely sure without taking some stuff apart.

When I was re-running the entire vacuum system in my car, I think you are talking about the valve for the secondary air pump. There should be a line running from the intake manifold tee to a check valve, then an electronic valve, then to the solid vacuum line near the vanos solenoid

http://realoem.com/bmw/showparts.do?...39&hg=11&fg=45

19 runs to the vacuum canister
10 is the hard line near the vanos solenoid
7 and 5 are the electronic valve/solenoid and one way check valve under the manifold runners 1-3

The vacuum system in the E36 is a ticking time bomb IMO, and its location under the intake manifold just means that chances are the hoses havent been replaced unless the manifold has been off. I highly suggest replacing every single vacuum line under the intake manifold, as well as the one way valve #5. I used black silicone vacuum line because I had some left over from a turbo build, and I doubt they will ever need to be replaced in the future. Rubber vacuum lines just fall apart due to age/heat/winter cycle.

[MParallel]

Oh hell you have that extra emissions airpump right? Not in mine for goodness sake.

I believe my exhaust flap is controlled by a vacuum line coming from the manifold.

I could see some sense in the fact that if there is a carbon canister in the trunk, that this would be more easy to control the flap, but the one behind and below the airbox on the M52's. The diagram in the ETK doesn't convince me this not being true.

But then again, maybe there more US-spec vs. Euro-spec than I know. I was even surprised the US M52 (maybe only early production ones) have a cast-iron cilinder block, while ours is all-alu.

[DJCarbine]

Oh hell you have that extra emissions airpump right? Not in mine for goodness sake.

I believe my exhaust flap is controlled by a vacuum line coming from the manifold.

I could see some sense in the fact that if there is a carbon canister in the trunk, that this would be more easy to control the flap, but the one behind and below the airbox on the M52's. The diagram in the ETK doesn't convince me this not being true.

But then again, maybe there more US-spec vs. Euro-spec than I know. I was even surprised the US M52 (maybe only early production ones) have a cast-iron cilinder block, while ours is all-alu.

No wonder you questioned me, you are going off Euro spec design

The US spec OBDII 328i has charcoal canister in the trunk as part of the evap system, under the spare tire. The vacuum canister in the engine bay is to keep the muffler flap closed even while the car is off, so the next time you start the car the muffler will be in "quiet" mode.

I hate how euro/japanese spec is always different from US spec cars. They really dumb down the car with extra emissions crap

[MParallel]

But then the vacuum canister would be something else as the carbon/charcoal canister, which is what is pictured in the original post...

Well some UK cars, specially M3's also have the extra emissions pump and someone I know who had a 1993 M3 3.0 had an extra pump under the hood, which was very surprising.
So even some Euro's have bad parts.

But yes, in general speak, you guys usually get lobotomized. US M3 240 horses, we get 321. That's 81 horses stolen from you guys.

[doogee]

That is 100% the vacuum canister for the exhaust flap.

[MParallel]

So it's not this part?



Which is the Activated Carbon Filter and has nothing to do AT ALL with the exhaust flap.

[doogee]

So it's not this part?



Which is the Activated Carbon Filter and has nothing to do AT ALL with the exhaust flap.

No sir. They look very similar. But this is too small to be the charcoal canister and doesnt have the right connections

[MParallel]

So that was what caused this confusion.

I don't recall ever seeing that part that the OP posted in my engine bay.