Fill up your tank and smell gas for next 3 hours of driving? - I had changed all the little tubes on the top of the tank to no luck, i changed this o-ring and no more fumes!
Change this part
62168782015
or 16111744369
Part 8 on this diagram
ADDITION/UPDATE:
E21 Shop manual says:
"The cord ring seal (6) will swell in contact with gasoline, and must therefore be renewed whenever the unit is removed"
Also:
I had this problem too, i think it solved it but I have yet to go under the car and confirmbusemans
i wonder if that is why gas runs down the tank after filling up. its coming from that area but i never really dug into it
Last edited by g323; 12-14-2008 at 03:24 PM.
Interesting... will be looking into this...
Great info! I was running out of ideas on this issue, thanks.
It works, I did this a couple years ago and the smell is gone, I was always hesitant to fill up my tank because of it.
i wonder if that is why gas runs down the tank after filling up. its coming from that area but i never really dug into it
No e30s again.
Good tip and I will order the part on Monday. I have been trying to figure this one out for a few months. The fumes have gotten so bad my wife wouldn't get in the car to go to the Christmas tree lot. We had to drive to separate cars because the e21 is the only car with ski racks to support the tree. It worked out okay because I raced a mustang GT on the way there. Did the burn out right in front of my wife as she was in her car behind me. Couldn't resist.
haha I think I used an M20 thermostat housing O-ring in that spot. Wonder if it will hold up...
i replaced my m20 thermostat housing O ring the other day and was thinking to myself how similar it looked to the other one haha I hope it works for you!
Last edited by g323; 12-14-2008 at 05:13 PM. Reason: clarity
Thanks for the tip. Preparing to install new interior in car, now would be the time to change that o-ring!
Just a note to add here, the o-ring may not be the only problem. Even after replacing all the hoses and replacing the O-ring I ended up with a leak. I found that the locking tabs on top of the gas tank were all bent up which prevented a proper seal even with a new o-ring. I had to gently tap them flat again with a hammer for it to seal properly again.
Also, just as common are the tank vent fuel lines. Hoses numbered 3 (12mm diameter) and 4 (14mm diameter) in this diagram were not fuel rated and are usually deteriorated, brittle and cracked. It is very difficult to find fuel line in metric that large in the states. I was able to find 7/16" at my local Napa.
is this accessible from the panel underneath the seats?
You can replace the O-ring by just pulling the access panel. To replace the vent lines you have to unbolt the tanks and let them hang slightly to gain access. You don't have to remove them completely, but it still sucks. A helping hand is... helpful.
Do you really need to drop the tanks a bit to replace the vent lines? what about a having the new hose handy-connecting the old to the new via a pvc tube and clamps- then pulling it through?
My Website
1982 323i
Under the Hood:
M20B23, Dogleg tranny, K&N Box Air Filter, Hayden 11inch Pusher Fan, redline tranny/diff fluid, Dual Exhaust,3.45 open.
Braking/Suspension:
Steel brake lines in front, front/rear 323i disks, Front and Rear Strut Braces, Lower Alpina(Ken) Bar, Kmac Camber/Castor Plates(Raise the front 1 inch), PolyUrethane Steering Rack Mounts, Rims = RG alloy wheel set (BBS design) silver 6x13“ KBA 40324, Tires: Sumitomo 195/60/13, Struts: Bilstien HDs Springs: Stock
Body:
087-Graphit-metallic, Euro Bumpers, BBS Valance, Foha Rear Spoler, Yellow Hella High Beams
Interior:
Recaro Front Seats, Sports Steering Wheel, Kph 220 Speedometer, Vacuum gauge, Air/Fuel Gauge
how are you going to cut the old crimped on hose clamp and remove the old hose from the driver's side tank? That's the only reason you need to lower them, the passenger side you can do from the access panel.
Keep in mind the tanks are connected, it's best to lower them as a pair, with the tanks as empty as possible. You don't have to remove them, just unbolt the rear bolts, loosen the front bolts, and rotate them down enough to get your hands in. Supporting them with a jack is a good idea.
I also recommend smoking a large cigar while doing this job. It will take the edge off.
ha K-jetman recomends smoking during fuel line jobI also recommend smoking a large cigar while doing this job. It will take the edge off.
Didn't look closely enough at the diagram, for some reason I thought the lines underneath the access panel went into the trunk near the fillup socket-I forgot about the little aux tank.how are you going to cut the old crimped on hose clamp and remove the old hose from the driver's side tank? That's the only reason you need to lower them, the passenger side you can do from the access panel.
A question about tipping off the tank:
When I fill up the tank and the gas gun shuts off-has the aux tank filled at that point? Or must I tip off the tank?
My Website
1982 323i
Under the Hood:
M20B23, Dogleg tranny, K&N Box Air Filter, Hayden 11inch Pusher Fan, redline tranny/diff fluid, Dual Exhaust,3.45 open.
Braking/Suspension:
Steel brake lines in front, front/rear 323i disks, Front and Rear Strut Braces, Lower Alpina(Ken) Bar, Kmac Camber/Castor Plates(Raise the front 1 inch), PolyUrethane Steering Rack Mounts, Rims = RG alloy wheel set (BBS design) silver 6x13“ KBA 40324, Tires: Sumitomo 195/60/13, Struts: Bilstien HDs Springs: Stock
Body:
087-Graphit-metallic, Euro Bumpers, BBS Valance, Foha Rear Spoler, Yellow Hella High Beams
Interior:
Recaro Front Seats, Sports Steering Wheel, Kph 220 Speedometer, Vacuum gauge, Air/Fuel Gauge
Auxillary tank? I'm talking primarily about the line that connects to top of the 2 main tanks. This lines purpose is to allow air to travel from one tank to the other so that as fuel is pulled or added to 1 side, the level can freely rise or lower in the other without pressurizing or depressurizing air.
The line that runs to the fill tube and the small vapor tank should also be replaced for good measure.
You should NEVER top off the tank any further after it shuts off, and you should never try to fill the little vent tank (not even sure how you would). That is to prevent fuel overflow (from topping off the tank) from traveling up to the engine bay and ruining the carbon canister.
Its called a vapor tank? I thought I had always seen that the tank was something like 52 liters plus 6 liters when including the aux tank.
http://www.bmwe21.net/e21/us320i/
This is the piece im talking about: Its called:09EXPANSION TANK
1
16121118911$26.51
As to the point about topping off, I dont and know about killing the carbon canister. Whats the deal with the 320i/323i owners manual talking about testing mileage, it talks about filling to the brim or some such phrase,,,Ill look it up tomorrow if I get a chance.
EDIT: I have the pdf version of the manual so here is:
Commandment 10:
Having faith is good, checking is better
The secret of energy conscious driving is
knowing exactly what your car consumes.
Only if you establish what the effects of
different driving styles are on consumption
and what readjustments can do for
the engine will you act and react with
greater awareness in the future.
Keep a constant check on how much fuel
you use.
Preconditions for fuel consumption measurement
1. The engine must be broken in.
2. Fill the tank to the brim.
3. The car should be perfectly level wher)
you fill up.
4. Get rid of air bubbles in the tank by
rocking the car.
'Check as you drive';
Try to maintain a constant 90 or 120 km/h
(56 or 75 mile/h) in direct top (4th gear).
'Observe' -
Measuring the consumption
After finishing yOur journey, fill the lank to
the brim again.
Last edited by g323; 01-05-2009 at 11:01 PM.
My Website
1982 323i
Under the Hood:
M20B23, Dogleg tranny, K&N Box Air Filter, Hayden 11inch Pusher Fan, redline tranny/diff fluid, Dual Exhaust,3.45 open.
Braking/Suspension:
Steel brake lines in front, front/rear 323i disks, Front and Rear Strut Braces, Lower Alpina(Ken) Bar, Kmac Camber/Castor Plates(Raise the front 1 inch), PolyUrethane Steering Rack Mounts, Rims = RG alloy wheel set (BBS design) silver 6x13“ KBA 40324, Tires: Sumitomo 195/60/13, Struts: Bilstien HDs Springs: Stock
Body:
087-Graphit-metallic, Euro Bumpers, BBS Valance, Foha Rear Spoler, Yellow Hella High Beams
Interior:
Recaro Front Seats, Sports Steering Wheel, Kph 220 Speedometer, Vacuum gauge, Air/Fuel Gauge
What kind of material is this and the pressure valve o-rings which makes them so special?
My Website
1982 323i
Under the Hood:
M20B23, Dogleg tranny, K&N Box Air Filter, Hayden 11inch Pusher Fan, redline tranny/diff fluid, Dual Exhaust,3.45 open.
Braking/Suspension:
Steel brake lines in front, front/rear 323i disks, Front and Rear Strut Braces, Lower Alpina(Ken) Bar, Kmac Camber/Castor Plates(Raise the front 1 inch), PolyUrethane Steering Rack Mounts, Rims = RG alloy wheel set (BBS design) silver 6x13“ KBA 40324, Tires: Sumitomo 195/60/13, Struts: Bilstien HDs Springs: Stock
Body:
087-Graphit-metallic, Euro Bumpers, BBS Valance, Foha Rear Spoler, Yellow Hella High Beams
Interior:
Recaro Front Seats, Sports Steering Wheel, Kph 220 Speedometer, Vacuum gauge, Air/Fuel Gauge
The material is viton which is very fuel resistant compared to the common nitrile (buna-n) o-rings found in your hardware store.
Yup, gotta lower the tanks to get to the edit: driver-side (top) tank vent hose nipple. All the other hose conns should be accesible. I think I used 7/16" as well when I replaced all my old vent hoses.
I'm guessing they used better rubber for the tank top o-ring in '78 because I'm still using the original o-ring and the sending unit has been out 4 times since I've had it. I just keep it lubed with multi-purpose grease when I re-use it, and it still holds a tight squeeze. No fumes either (knock on wood)...
Anyways g323, excellent safety topic, Robert
Last edited by epmedia; 07-10-2009 at 05:20 PM.
Tbd
Final common failure point on the tanks are the seams between top and bottom halves.
I had replaced all hoses and gaskets but was still getting horrible stink.
I finally dropped the passenger tank in frustration to find that the seams had rusted through near the top. What was confusing is the seams run down and to the front so although the leak was at the top rear, gas would appear at the bottom front.
But wait, it gets even better!
I pulled, diagnosed, replaced and sealed the *passenger* tank and guess what!? It still reeks of gas when I top it off! I bet you can guess where the smells coming from.
Way to rush the job, dip$h!t.
Eric P.
Was working on replacing the o-rings last night, and I was unable to get the fuel gauge structure out of the tank. The bottom lip of the cylinder kept catching on edge of the tank opening. I managed to stretch the o-ring over the top and secure it down, but could not make sense of not being able to remove it completely.
What was I doing wrong?
Its a very tight tolerance, a bit of twisting and fiddling and you should be successful.
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