Charcoal canister

Blaise · Post by **Blaise** » Mon Jan 23, 2012 1:37 am

My charcoal canister is looking like it per-dates my car. I am trying to figure out when one is replaced and how one knows when they stop functioning properly.

In googling, I just find that the check engine light will provide a code when it is time. No help there.

T.Hanson · Post by **T.Hanson** » Mon Jan 23, 2012 9:40 am

The best place to Google search topics is here, the archives of this site. Posting a question is easy, convenient and personal, but it requires a personal answer. That requires one of the (fewer) experts to read it, know the answer and take the time to type it, soon, fast.

Notice the number of enthusiasts visiting this site when it began, (archives) vs. now.

My simple answer would be to visit realoem.com., check out the drawing and part number for your car and buy that part. I don't remember them as being hugely expensive. Like an oil filter, too new won't hurt anything.

Mike or LennyD. or Larsoldbimmerguy etc. might drop by and be in the mood to teach us (again, see archives) what the cat, oxygen sensor, charcoal filter do, or mess up if neglected. Or, we can Google the exhaust recycling, emissions technology of the early eighties to understand the functions of the components ourselves.

Blaise · Post by **Blaise** » Mon Jan 23, 2012 1:28 pm

T.Hanson wrote:The best place to Google search topics is here, the archives of this site. Posting a question is easy, convenient and personal, but it requires a personal answer. That requires one of the (fewer) experts to read it, know the answer and take the time to type it, soon, fast.

Notice the number of enthusiasts visiting this site when it began, (archives) vs. now.

My simple answer would be to visit realoem.com., check out the drawing and part number for your car and buy that part. I don't remember them as being hugely expensive. Like an oil filter, too new won't hurt anything.

Mike or LennyD. or Larsoldbimmerguy etc. might drop by and be in the mood to teach us (again, see archives) what the cat, oxygen sensor, charcoal filter do, or mess up if neglected. Or, we can Google the exhaust recycling, emissions technology of the early eighties to understand the functions of the components ourselves.

I agree and apologize if I ask too soon. I know that I ask a lot of questions, but it is due to the fact that I have been knee deep into my restoration for the past nine months. I am now soo close to turning the key.

I did do some searching on this site and the archives regarding the charcoal canister. I understand what it does.

I am still unclear as to how one determines if it is still good, or not.

Thank you all for your support.

T.Hanson · Post by **T.Hanson** » Mon Jan 23, 2012 2:27 pm

Not to be misunderstood as a slap on the nose, only a head's up the traffic for answers is getting sparse.

Only because they are not expensive, I replaced mine just from probable years in service, and not finding a test procedure,...either.

I know it's better to play by the (green) rules, keep, replace the cat etc. rather than spend wrong headed time and money thinking there's a big performance advantage in dumping the emission pieces.

Still, my 635 never had a canister in it for ten years, while I never knew there was supposed to be one. Wasn't or was made the engine run no different that I could notice. Like little teeny vacuum tubes filtering vacuums through charcoal crumbs ? Old or new crumbs ? What.

Luis A. · Post by **Luis A.** » Mon Jan 23, 2012 4:22 pm

Blaise,

This system is pretty close to that on my E3 and utilizes the same canister. First off, it's pricey at around $120 list so about $100 after the 20% discount. The canister passively filters out raw gasoline fumes from the expansion tank which is essentially a liquid/air separator.

That price had me looking for a canister that would be close enough, but cheaper than the BMW one. The friendly NAPA guy pulled out his illustrated parts book and while there are some that are close enough to work, none were cheaper than the BMW one.

If you can smell raw gas fumes emanating from the canister, then the charcoal is spent.

I only need it for looks, so I will blast and repaint mine. If I had your welding skills, and needed a functional one, I'd open it up with a can opener, or a dremel, at the seam, refill it with activated charcoal and weld it back up.

Falkenberg · Post by **Falkenberg** » Mon Jan 23, 2012 4:31 pm

Blaise wrote: I know that I ask a lot of questions, but it is due to the fact that I have been knee deep into my restoration for the past nine months.

And once you are finished, I hope that you will answer questions posted by the next guy starting such a project (such as myself)

Blaise · Post by **Blaise** » Mon Jan 23, 2012 4:32 pm

Falkenberg wrote:
Blaise wrote: I know that I ask a lot of questions, but it is due to the fact that I have been knee deep into my restoration for the past nine months.
And once you are finished, I hope that you will answer questions posted by the next guy starting such a project (such as myself)

Of course, that is how it is meant to be. I try to do this already.

Lenny D. · Post by **Lenny D.** » Wed Jan 25, 2012 10:44 pm

All good answers above. Including the one about opening the old one up like a soup can and replacing the charcoal (aquarium supplies) with new. That's what us veedubbers do with canisters from the '70s (yes they intsalled them way back then). Or buy a new one.

The idea (in 1980) was to capture raw gasoline fumes via the charcoal and route a line to the intake manifold to be burned upon startup. It worked well for its time until automotive design progressed

to where it is today.

From the original owner's manual,

Check connections of Evaporative control system at 15, 30, and 60K mi. There are no maintenance guidelines past that

Remember, the Germans never dreamed of anyone driving their vehicles for 30+ years. At this point we are on our own.

Lenny D. · Post by **Lenny D.** » Wed Jan 25, 2012 11:07 pm

To further answer T. Hanson's questions:

The 'Cat' was/is a way to 'control/limit' what your (mine and our) engine(s) expel(s) into the atmosphere that we get to breathe as a by-product of combustion that moves us from point A to B. Notice dragsters have none of this, ergo these systems have nothing to do with the performance of your engine per se' but its failure does. The O2 sensor however, is part of your engine management system. Since its development it has allowed fine, dynamic adjustments to idle mixture for maximum combustion efficiency (look up 'stoichiometric ratio' and read).

Simple logic says time=wearing out, using up of resources. Maintenance, parts replacement prolong a vehicle's life and here we are keeping dead bodies alive way past their design expectancy

Blaise · Post by **Blaise** » Wed Jan 25, 2012 11:42 pm

Lenny D. wrote:To further answer T. Hanson's questions:

The 'Cat' was/is a way to 'control/limit' what your (mine and our) engine(s) expel(s) into the atmosphere that we get to breathe as a by-product of combustion that moves us from point A to B. Notice dragsters have none of this, ergo these systems have nothing to do with the performance of your engine per se' but its failure does. The O2 sensor however, is part of your engine management system. Since its development it has allowed fine, dynamic adjustments to idle mixture for maximum combustion efficiency (look up 'stoichiometric ratio' and read).

Simple logic says time=wearing out, using up of resources. Maintenance, parts replacement prolong a vehicle's life and here we are keeping dead bodies alive way past their design expectancy

Got it. Thank you.