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?

http://img31.picoodle.com/img/img31/4/5/10/f_DSC00114m_7381b67.jpg (http://www.picoodle.com/view.php?img=/4/5/10/f_DSC00114m_7381b67.jpg&srv=img31)

http://img29.picoodle.com/img/img29/4/5/10/f_DSC00116m_447497a.jpg (http://www.picoodle.com/view.php?img=/4/5/10/f_DSC00116m_447497a.jpg&srv=img29)

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.do?model=CB12&mospid=47441&btnr=13_0372&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!

[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! :p

[Kibokojoe]

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

[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! :D ), 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! :D ), 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.

[ThoreauHD]

Charcoal canister.

Part # : 16 13 1 181 217
$ 54.95

bavauto.com

[anonymous1]

Hi,

Much appreciated on all information and way to diagnose. I checked the line going from the canister to the intake (Seems to connect at the throttle body?) and it hasn't got anything on it that I can feel/see. I'm going to order a new canister for the weekend and see how much the hoses and fuel line are in case I need to replace those as well. (I'm taking it that I'll be best to de-pressurise the system when changing the canister over?)

It'll just add to the list of jobs for the weekend, also including a new thermostat housing (due to the old one crying and wasting me some coolant!), fitting new shocks to E34.sports' vehicle, carrying out compression test on mine and sure they'll be a couple of others still to come up, after all there are 3 more days for them to be discovered. :D

Here's to this getting rid of the problem and me being able to pull out from junctions without wondering if today will be the day the car doesn't shift like it should and I find a lorry nestling in my lap. :p

Thanks again.

[anonymous1]

Hi,

Changed the Canister at the weekend, one of the easier items in the engine to get to for once. This seems to have cured the problem, the old one was making a rattling sound when I took it out (Not sure if this is normal after time - but the new one didn't). I initally thought it was still there, so opened the fuel cap (Engine turned off), not sure if this equalised the pressure or if it simply took a little while for the new canister to kick in, but seems OK since.

I did also get the pipe that goes back to the fuel tank, but hoping to avoid dropping the tank if I can.

Thanks for all the advice, much appreciated and here's to it staying gone.

[anonymous1]

Hi,

Just when I though I was in the clear, the little annoyance had reared it's head yet again! Stayed gone for over a week after the canister change.

I'm wondering if it could be something to do with the valve between the carbon canister and the throttle housoing that could be causing the issue. #1 on this: http://www.realoem.com/bmw/showparts.do?model=CB12&mospid=47441&btnr=13_0372&hg=13&fg=15

Although I am also thinking it could be something to do with the level of fuel I have in the car. After changing the canister I went and put just over half a tank in and the noise/hesitation left me alone for a week. Now it is back on a quarter it is back... I thought I had noticed this in the past, but then put it down to being in my head. Could this link to the problem I am having... Fuel sender or reg? Or could it be that once the fuel is this low there is more of a vacuum and thus it becomes more noticeable? I'm lost!

I do have the pipe which goes from the canister to the tank, but if I can avoid dropping the tank, only to find out it's not this I'd prefer to. (looks like a pain with the double tank type setup!)

Thanks in advance for any ideas.

[Morgenster]

The magnetic valve may be faulty and stuck open. Usually this part can be removed and cleaned. It's right next to the canister. Try that first.
alternatively it could also be the FPR. If the FPR lets through too much fuel back to the canister You could be having a brand new broken canister.

[anonymous1]

Thanks Morgenster, I'll have a look at that this weekend, think I noticed the part you mean, I had to remove it from the bracket on the old canister. Can I use Carb/Brake Cleaner on it or can it just be wiped clean?

I'm hoping it's not damaged the new canister, at £30 a pop I can't really afford to have to swap it again, especially if I do have to change the fuel reg as well. (Which from looking at my engine I am guessing is at the end of the fuel rail nearest the fire wall in a position that seems ridiculous for anyone lacking rubber/monkey arms to get at :D - without removing the rail itself first?)

Thanks again and hopefully this time I'll be able to say goodbye to it for good!!!

[Ross]

I'm wondering if your tank is vented at all. If you are trying to draw fuel from a tank that is a partial vacuum that makes the fuel pump's work very hard indeed. Try releasing the cap when the fuel is low and the problems begin to relieve any accumulated vacuum.

[anonymous1]

I'm wondering if your tank is vented at all. If you are trying to draw fuel from a tank that is a partial vacuum that makes the fuel pump's work very hard indeed. Try releasing the cap when the fuel is low and the problems begin to relieve any accumulated vacuum.

Hi,

Thanks, I'll give this a try and report back. I haven't noticed any release/hissing noise when I remove the cap to fill with petrol; is this something I would get if it was a build up of vacuum? The only noise I am getting at present is a loud bang/pop from what sounds like the right side of the engine lower down. When I get this, the car hesitates for a second or so and then the power kicks back in and I'm away. I can live with this to an extent, but concerned it will cause more problems over time.

Cheers again.

[Morgenster]

Thanks Morgenster, I'll have a look at that this weekend, think I noticed the part you mean, I had to remove it from the bracket on the old canister. Can I use Carb/Brake Cleaner on it or can it just be wiped clean?
Affirmative on location, not so sure on how to clean it, but it only has one moving part and carb cleaner won't kill it AFAIK. If it's jammed it'll likely be visibly so.


I'm hoping it's not damaged the new canister, at £30 a pop I can't really afford to have to swap it again, especially if I do have to change the fuel reg as well. (Which from looking at my engine I am guessing is at the end of the fuel rail nearest the fire wall in a position that seems ridiculous for anyone lacking rubber/monkey arms to get at :D - without removing the rail itself first?)
Again, affirmative on the location of the FPR. But I wouldn't swap the sucker out before testing fuel pressure with an inline pressuretester and checking the values on idle and increased throttle. If it's stuck open to 'return to tank flow' you'd probably notice fuel pressure is low on increased throttle.

[anonymous1]

Affirmative on location, not so sure on how to clean it, but it only has one moving part and carb cleaner won't kill it AFAIK. If it's jammed it'll likely be visibly so.


Again, affirmative on the location of the FPR. But I wouldn't swap the sucker out before testing fuel pressure with an inline pressuretester and checking the values on idle and increased throttle. If it's stuck open to 'return to tank flow' you'd probably notice fuel pressure is low on increased throttle.

Thanks for the additional advice, I'll definately be having a look at the weekend. I'm not sure if this is relevant or not, but the old canister I took out was bone dry, and none of the hoses had anything in them... Should there have been some fuel in there somewhere?

[Kibokojoe]

Should be no fuel just fumes.

QUOTE=CaptainGoSlow]Thanks for the additional advice, I'll definately be having a look at the weekend. I'm not sure if this is relevant or not, but the old canister I took out was bone dry, and none of the hoses had anything in them... Should there have been some fuel in there somewhere?[/QUOTE]

[anonymous1]

Hi,

Thanks for all the input. I took the valve off yesterday and cleaned it as best I could. Then changed the vent pipe that goes from the canister to the tank, tried putting water through the old one (once it was off:D ) and seemed to be meeting some resistance, I then opened the filler cap to release any pressure, so I was hopeful this was the problem.

However, after starting it up, I still seem to be able to get the noise (loud bang) from the engine compartment at low revs. Myself and E34.sport have both listened and now think it may be coming from the exhaust manifold, so thinking I poss have a bad gasket. Is it possble this would only show up when starting to put your foot down at low revs? The bang only happens every now again, not everytime I try to accelerate from low revs. I seem to be able to get it to happen if I say hold the vehicle at 30mph in 3rd (although the gear I'm in bears no relevance as long as right rev range) and then I drop down to 20mph or just under, then I put my foot back down and bang comes from the engine, along with a loss in power.

I also found a slice in a vacum hose that goes off the MAF elbow underneath the iontake, but spraying this with carb cleaner didn't bring any rise to the idle.

I did manage to drive the car for over a hour last night without getting the symptom, to this just kept the revs above 1,000. Do I need to worry or should I just carry on driving at a slightly higher rev range where I do not get the issue?

Thanks again. (Hope that all made sense!)

[jofusfarr]

have you checked fuel pressure yet?

I had these similar symptoms when I was losing fuel pressure due to a defective fuel pump.