Anyone know what this is?

[anonymous1]

Hi,

In the search for my hesitation and misfire, I have come across this part but am unsure what it is. E34.sport stood over the engine while I revved it and the crack/pop noise consistent with the hesitation came from this area. At the time of narrowing the noise down, we had taken the air box off and the noise seemed to come either from the MAF or from somewhere below it?





The only image on real.oem I can find that seems shows this part doesn't actually have a number/description for it. But it looks like it is part of the fuel system. http://www.realoem.com/bmw/showparts...72&hg=13&fg=15

I am wondering if this problem could either be caused by this part, or alternatively as it seems to be within the fuel system should I be looking to replace the pump and regulator.

I will be doing a compression test to see if I have a problem with valves/head, but don't think (hope) this is the case as it's an intermittent issue I have been having now for a while.

Thanks in advance.

[Kibokojoe]

Isn't that the fuel tank breather canister? Doesn't it have a carbon filter in it?

[BMWDriver]

Almost sounds like the fuel is backfiring out the intake.

[Kibokojoe]

Then it sounds like the vent line from the fuel tank has a problem. Can you get air through the vent line? Could be plugged. Isn't this line suppose to pull fumes from the fuel tank?

[repenttokyo]

looks like the charcoal canister to me, but I don't see why it would be making a noise.

[e34.535i.sport]

looks like the charcoal canister to me, but I don't see why it would be making a noise.

Hey not to hijack the Captains thread but should I have one of these... I sure as hell can't find it if I do!

[Kibokojoe]

I don't have one on my 1989 E34 either. Its environmental crap. Traps gasoline fumes. Something else to go bad.

[e34.535i.sport]

I don't have one on my 1989 E34 either. Its environmental crap. Traps gasoline fumes. Something else to go bad.

Good stuff... I have enough on the to-do list at the moment!

[anonymous1]

Hi,

Thanks for the information. Is it likely that I would need to replace the canister, or is it normally a non-service item? Unsure due to there not being a part number on real.oem for it is all.

There seems to be 3 lines going into/out of the canister, does fuel actually go through it, or does it just suck fumes from the tank itself? Wondering if I just need to possibly change the hoses and if so whether I'll need to depressurise the system? The noise only seems to happen at lower end revs, presume before the pressure builds and forces it's way through, which I'm guessing would also explain the hesitation in accelaration if the fuel pressure is being affected as a result.

If it is back firing (Which would explain the loud cracking/popping noise I get - although it's not as bad as the one Uncle Buck has! ), can it cause any further damage? I only ask, as I was recently under the front end and noticed that the exhaust manifold coming off the 3rd cyclinder seems dis-coloured (dark - as if damp) compared to the other 5. Or would this be a separate issue - possibly gasket related?

Sorry so many questions, I have no idea in this area.

Thanks in advance.

[Morgenster]

Hi,

Thanks for the information. Is it likely that I would need to replace the canister, or is it normally a non-service item? Unsure due to there not being a part number on real.oem for it is all.

There seems to be 3 lines going into/out of the canister, does fuel actually go through it, or does it just suck fumes from the tank itself? Wondering if I just need to possibly change the hoses and if so whether I'll need to depressurise the system? The noise only seems to happen at lower end revs, presume before the pressure builds and forces it's way through, which I'm guessing would also explain the hesitation in accelaration if the fuel pressure is being affected as a result.

If it is back firing (Which would explain the loud cracking/popping noise I get - although it's not as bad as the one Uncle Buck has! ), can it cause any further damage? I only ask, as I was recently under the front end and noticed that the exhaust manifold coming off the 3rd cyclinder seems dis-coloured (dark - as if damp) compared to the other 5. Or would this be a separate issue - possibly gasket related?

Sorry so many questions, I have no idea in this area.

Thanks in advance.

Check the line from the canister to the intake manifold at the end connecting to the manifold. If it's really slick with gasoline it's probably inhaling to much of it. Since it's a vacuum line it'll suck the most at lower revs because vacuum in the manifold and the line are highest then. Which in turn would cause backfires.
The culprit is most likely the canister itself since it will take in fuel diverted by the FPR, filter it, and then split off the fuel back to the tank and the vapours to the manifold. If it's just vapour diverted to the manifold then it's ok. If it's more you have trouble.
It could also be the line from the canister back to the fuel tank. If that's blocked the canister will spew fuel into the vacuum line. If you're lucky it's just a local blockage at the canisterside that you may be able to clear out yourself.