fuel smell

[resunoiz]

as everytime, I filled engine to full tank. gone home, nothing but engine indicator a 3/4, not moving. I did'nt care too much about, is not the first time it goes "sleep" and starts whenmever he wants.
had lunh, and at 16.00 pm took the car, made 5-6 turn on the city, and the indicator always a 3/4, not moving.
suddenly in the sterets, an intense, very intense fuel smell. had to stop, very afraid honestly, shut down the car. checked the fuel cap was ok (think it was), no leaks. the smell seemed from inside, NOT so strong outside.
restarted the car, little anxious, the engine indicator slowly went to full (as it should). the smell slowly went away, is slightly perceptible now, I think because it was veeery strong and quite hard to leave. interior carpet is dry, the 3 hoses from the tank under the car seems ok.

what to check? I'm a bit afraid....

[dcrothers]

Fuel smell is definately scary. I would get the car up on jack stands. Trace the fuel lines as best you can from the engine bay to the tank and fuel pump.
Look for any sign of a leak,obviously.
It could have been a clog or sometthing causing fuel to back-up.
Guys have reported good luck with using SeaFoam in the gas tank to clear any glogged or gummed up sensors.
When it comes to fuel leaks, if you are not a confident and competant DIYer it's best left for a pro to diagnose and fix.

[JoshS]

95% of the time, this is the seal on your gas cap. They fail over time. Start with the easy thing. Just get a new one.

[Vintage42]

... suddenly in the sterets, an intense, very intense fuel smell. had to stop, very afraid honestly, shut down the car. checked the fuel cap was ok... no leaks. the smell seemed from inside, NOT so strong outside... slightly perceptible now, I think because it was veeery strong and quite hard to leave. interior carpet is dry, the 3 hoses from the tank under the car seems ok...

The fuel tank has an access plate behind the passenger seat. When the passenger seat is removed, there is a large flap of padded carpet behind the seat that lifts to reveal the access plate and the electrical connections to the fuel tank. Move your passenger seat full forward and see if that allows the carpet flap to be pulled open enough for inspection of the tank.

[Randy Forbes]

95% of the time, this is the seal on your gas cap. They fail over time. Start with the easy thing. Just get a new one.

Ding, ding ding!! Happened to me last night; made a hard-long sweeping left turn with a full tank and a near immediate very strong gasoline smell. Top was down, and the vapor smell dissipated quickly. On the return trip, right near home I made another sharp-fast left and the same thing, so as soon as I got to the garage, I pulled the cap and could see where the seal was wet to the edge and there was just a hint of liquid left in the rubber well.

Well, the rubber lanyard gave way about a month ago, so the cap leaking is a better reason to buy a new cap

[resunoiz]

95% of the time, this is the seal on your gas cap. They fail over time. Start with the easy thing. Just get a new one.

waht part is? serial numer?

The fuel tank has an access plate behind the passenger seat. When the passenger seat is removed, there is a large flap of padded carpet behind the seat that lifts to reveal the access plate and the electrical connections to the fuel tank. Move your passenger seat full forward and see if that allows the carpet flap to be pulled open enough for inspection of the tank.

never understood if the carpet part for inspection t is only hole-shaped or effectively cutted. how can I remove it?

[Kenn]

I had this issue for a while years ago. I would only smell gas inside my garage, and only with full tank of gas. By the time it was down to 3/4 or so, no more smell. It turned out to be the plastic ring that holds the fuel pump/sender unit onto the gas tank had worked its way loose (not even hand tight). With a full tank, gas would seep from the gasket, and it was even pooled inside the outside top of the fuel pump/sender unit, and once it was full, excess would drip to the garage floor and evaporate. The fix was free and easy - just tighten the ring. There's a special tool to tighten the ring, but some careful taps with a hammer on a screwdriver onto the ridges around this ring work also.

The carpet has cut sections in it over the access point to this unit (like a dotted line), and you need to cut between the already-cut sections to get access. (Mine was already cut, indicating pump/sender work or replacement before I bought the car, and whoever did that work didn't tighten the ring adequately - just hand tight most likely.) If you don't want to cut the carpet (pretty much invisible, since it's behind the passenger seat anyway, and the cut semicircle fits back into position), you could remove the carpet or drop the fuel tank. Neither would be all that easy.

[resunoiz]

thanks. reading you, there are a lot of causes, not necessarily exprensive, but a lot ot stuff to search.

I'm little afraid too...

[Vintage42]

Behind the passenger seat of my 1997 (built in 10/96) 1.9L, there is a large semi-circular flap in the vertical carpet and its padding. The flap is molded into the carpet and foam backing, and was not cut into the carpet. When I had the seat out, I just pulled open the flap and looked at the access plate to the gas tank.
I also replaced the gasket on my gas cap because of its age, even though there was no problem with the old gasket. It was P/N 16 11 1 179 680, about $7 from BMW South Atlanta.

[resunoiz]

this s/n doesn't fit for Z3 on realoem...why?

what numer is for my schematic?
http://www.realoem.com/bmw/showparts...&fg=05&lang=it

[Vintage42]

Number 4 in these diagrams:
http://realoem.com/bmw/showparts.do?...05&hg=16&fg=05
http://parts.bmwofsouthatlanta.com/s...roduct=1327398

[dreamrider01]

The fuel gauge discrepancy may not be related to the fuel aromas you are experiencing. The fuel gauge in the Z is a bit useless. Just drive until the little orange light comes on. Then, hurry to find gas.

As far as the fuel smell - This may suggest a leak in the EVAP system. The most common cause is a bad fuel cap. Its diaphragm has developed a crack, and seal is compromised. Easy to test.

Other common problems that may cause this are:
1) Seal broken at a EVAP system lines junctions (someone noted this above).
2) Fuel logged Carbon Canister (another reason not to click-click-click that fuel pump until fuel spills out of the intake).
3) Cracked EVAP system hose.
4) Bad EVAP system solenoid, usually located near the carbon canister. Note: some of these have a mesh and rubber flapper on the intake side, which often get packed with road dust and dirt. These can be cleaned quite easily.
5) Bad Purge Valve solenoid, usually located near intake manifold.
6) Clogged EVAP system hose.

The easiest way to test the system for leaks (and before buying parts galore) is to pressurize it, about 10 mmHg, from the purge solenoid back (to the gas tank, not from intake manifold). It should hold pressure for about 10 minutes. If there is a leak, it should not hold pressure for more than 30 sec, anyway.

Another test is to remove the solenoids above described, hook them up to a fused line with your battery, and feel if they are triggering upon voltage application (usually 12V).

Also, check the canister for cracks, as well as for fuel logging.

Regardless, a CEL coming on is usually associated with the EVAP leak/problem, i.e.: ODB-II code will tell you if it is a small leak, or a large leak in the EVAP system. These codes come up rather quickly if there is a leak detected. However, you have not noted any ODB-II codes. May want to re-check ODB-ii codes, even if the CEL has not come on. They can be stored as PD.

[resunoiz]

The fuel gauge discrepancy may not be related to the fuel aromas you are experiencing. The fuel gauge in the Z is a bit useless. Just drive until the little orange light comes on. Then, hurry to find gas.

As far as the fuel smell - This may suggest a leak in the EVAP system. The most common cause is a bad fuel cap. Its diaphragm has developed a crack, and seal is compromised. Easy to test.

Other common problems that may cause this are:
1) Seal broken at a EVAP system lines junctions (someone noted this above).
2) Fuel logged Carbon Canister (another reason not to click-click-click that fuel pump until fuel spills out of the intake).
3) Cracked EVAP system hose.
4) Bad EVAP system solenoid, usually located near the carbon canister. Note: some of these have a mesh and rubber flapper on the intake side, which often get packed with road dust and dirt. These can be cleaned quite easily.
5) Bad Purge Valve solenoid, usually located near intake manifold.
6) Clogged EVAP system hose.

The easiest way to test the system for leaks (and before buying parts galore) is to pressurize it, about 10 mmHg, from the purge solenoid back (to the gas tank, not from intake manifold). It should hold pressure for about 10 minutes. If there is a leak, it should not hold pressure for more than 30 sec, anyway.

Another test is to remove the solenoids above described, hook them up to a fused line with your battery, and feel if they are triggering upon voltage application (usually 12V).

Also, check the canister for cracks, as well as for fuel logging.

Regardless, a CEL coming on is usually associated with the EVAP leak/problem, i.e.: ODB-II code will tell you if it is a small leak, or a large leak in the EVAP system. These codes come up rather quickly if there is a leak detected. However, you have not noted any ODB-II codes. May want to re-check ODB-ii codes, even if the CEL has not come on. They can be stored as PD.

thanks for the extemely precise (even if I don't know exactly some terms..I'll ask you if something is not so clear) response.

I know fuel indicator isn' accurate, at all. what made me think he could interfere was that usually it goes to top slowly, but goes. and when it decide to not operate, stops to red...and when he want to came to full. never remained "stopped" at a position. and the smell stopped with indicator making his "normal operation". but I truly trust you when saying it really doesn't matter.

I confess you that my ugly fear is fuel pump. But...is not time to cry now

- cap can be easily replaced with a low cost, not a big problem. BUT it will have a different key from the ones for the car now, being brand new? (my z is a pre facelift, has cap with key) or BMW will provide me a new cap that can be used with my keys?

- how to verify this seal? where exactly is? is a DiY work to do, check and eventually change?

- can you explain me point n. 2) ?

(another reason not to click-click-click that fuel pump until fuel spills out of the intake).

[Randy Forbes]

I ordered a new cap this morning through my old BMW dealer up in Ohio (that may not carry any weight to someone in Italy, I know...) and was told that it would be coded to suit my car; in other words, my existing keys would work in it.

Just to have them on hand, I also ordered a couple of cap seals; this is the rubber washer that you can see when you hold the cap in your hand and look at its underside.

Interesting that my car has not thrown a code, even though raw gasoline could leak past the cap. Was out in the car last night, and could exactly duplicate a couple of the lefthand turns, but with 1/2 full tank, no smell. Full disclaimer though: I usually round off the fuel numbers to the next dollar when I fill up, though I never have seen it "filled to the brim" and a couple days ago was the first time I can ever recall having the strong smell of gasoline in the car under any circumstances. Right now, my initial reaction to ANY abnormality, is that it's result of the recent twinscrew installation.

[dreamrider01]

- can you explain me point n. 2) ?

Only if you post a full picture of Miss Zuku!, and message me with her phone number...

Kidding aside; well, when you overfill until it spills out of the intake (some even rock their cars back and forth to get rid of air pockets...) the fuel rocks back and forth in the tank as one drives around. In doing so, some of the fuel may go into the EVAP system, which may end up in the Carbon Canister. The EVAP system is nothing but a fuel tank fumes recirculation for environmental benefit. Fumes from the gast tank are recirculated to the intake manifold and hopefully burned.

I was going to suggest a possible fuel delivery problem as a second option if all EVAP System components passed. Sometimes it could be as simple as a clogged fuel filter, or perhaps the tiny little wire meshes in the intake of the injectors. Then again, during prior fuel pump failures my vehicle simply stops. I gather mine were total failures.

[resunoiz]

- can you explain me point n. 2) ?

Only if you post a full picture of Miss Zuku!, and message me with her phone number...

think there a lot here in the forum if not, i can link you a lot of!

Kidding aside; well, when you overfill until it spills out of the intake (some even rock their cars back and forth to get rid of air pockets...) the fuel rocks back and forth in the tank as one drives around. In doing so, some of the fuel may go into the EVAP system, which may end up in the Carbon Canister. The EVAP system is nothing but a fuel tank fumes recirculation for environmental benefit. Fumes from the gast tank are recirculated to the intake manifold and hopefully burned.

I was going to suggest a possible fuel delivery problem as a second option if all EVAP System components passed. Sometimes it could be as simple as a clogged fuel filter, or perhaps the tiny little wire meshes in the intake of the injectors. Then again, during prior fuel pump failures my vehicle simply stops. I gather mine were total failures.

ok, thanks!

I ordered a new cap this morning through my old BMW dealer up in Ohio (that may not carry any weight to someone in Italy, I know...) and was told that it would be coded to suit my car; in other words, my existing keys would work in it.

Just to have them on hand, I also ordered a couple of cap seals; this is the rubber washer that you can see when you hold the cap in your hand and look at its underside.

thanks a lot to you too!

sincerely, never seen a gasket on the fuel cap.....

- - - Updated - - -

..but about the fact that smell seemed stronger INSIDE than outside?

what about this gasket?

[resunoiz]

I noticed the cap seal is wet in the center, BUT in the external aprt too..may be a sign of a failure of it, removing in fact a lot of my troubles?

in your cars, when you remove the cap, is wet to the external part fo that seal too, or not?

- - - Updated - - -

Number 4 in these diagrams:
http://realoem.com/bmw/showparts.do?...05&hg=16&fg=05
http://parts.bmwofsouthatlanta.com/s...roduct=1327398

the 1st link shows the correct part, BUT is not in the list and with no serial numer..don't know why.


the 2nd link clicking "details" says that is suitable for other cars, not Z3...in any case, no longer available...

[Randy Forbes]

the 1st link shows the correct part, BUT is not in the list and with no serial numer..don't know why.


the 2nd link clicking "details" says that is suitable for other cars, not Z3...in any case, no longer available...

Excerpts from my E-mail / parts order from a few days ago...

From: Erandyforbes
Sent: Monday, September 30, 2013 10:08 AM
To: Teresa
Subject: Parts order...

Hi Teresa,

A few parts for a car I'm working on, and my own car (LCXXXXX) needs a new gas-filler cap__this is the key-lockable type. Will it come already "keyed" to match my existing locks, or?

1 ea) 16 11 1 184 709 fuel filler cap

2 ea) 16 11 1 179 680 fuel cap seals

4 ea) 34 11 6 772 428 bolt

4 ea) 33 17 2 228 297 spacer

10 ea) 12 52 1 437 136 clips

Thanks, and please let me know about the gas cap.


Reply:

Good Morning –

The gas cap will come coded to your car. The spacers will be coming from Germany. I will ship everything as soon as it gets here & ship the spacers once they arrive.

Thanks for the order!!!

[Vintage42]

...
2 ea) 16 11 1 179 680 fuel cap seals...
Thanks, and please let me know about the gas cap.
...

The OP PM'd me about the part number for the gas cap seal. and I replied:

The part number 16 11 1 179 680 is the correct part for a Z3, according to the vendor's catalog page at:
http://parts.bmwofsouthatlanta.com/s...roduct=1327398
All the Z3 models use that gasket, according to the catalog listing:
Z3 1.9 (M44) Convertible: Up To 07/2001
Z3 2.5 (M52) Convertible: Up To 08/1999
Z3 2.8 (M52) Convertible: Up To 07/2001
Z3 2.8 (M52) Convertible: Up To 08/1999
Z3 2.8 (M52) Coupe: Up To 08/1999
Z3 M3.2 (S52) Convertible: Up To 08/1999
Z3 M3.2 (S52) Coupe: Up To 08/1999

[resunoiz]

thanks to all the replies, really

hope to solve...

- - - Updated - - -

this afternoon made some check.
fuel pump "cap" is tighten, no signs of something that could have "wetted" the surfaces.
no smell at all, even moving the hoses.


seeing the fuel cap terminal, saw some points to pay attention at:
- rubber gasket that is around the metal part of the tank was heavily rotten in various points, fuel that eventually can came there could go anywhere;
- the hose that connects this rubber gasket to the bottom of the car was detached (I knew it)
- the terminal part of the plastic tank where the filler cap screws on, is in metal (pic below). had 2-3 rectangular little cramps around it. one of them in the moment I touched it, fall under the chassis. what are they for? maybe to tighten the plastic and the metal parts together?
- is normal that this tank part lean on the car chassis? (pic below)



sorry for my bad english, think is hard to understand :P

[Vintage42]

... is normal that this tank part lean on the car chassis? (pic below)...

My filler neck is low in the opening. I do not think it is leaning on or resting against the body yet, and I don't know if this appearance is normal, or if it is a sag or a drop in some support. I also notice some wet gas has leaked from the cap gasket onto the rubber bellows that surrounds the filler neck. The leak was much too little to get near the drain hole. I wiped the whole area which made everything look wet.
I did not have a problem until I got into this thread. Now I will have to watch my filler.

1997 fuel filler.jpg

Maybe I should get #16 and #18 in the diagram at
http://realoem.com/bmw/showparts.do?...39&hg=41&fg=25

[resunoiz]

n. 18 is the rubber or metallic part? I can't understand viewing the diagrams..

[resunoiz]

n. 18 is the rubber or metallic part? I can't understand viewing the diagrams..

[Vintage42]

I don't know, but they are so cheap that I would buy both.

[resunoiz]

seeing tgat pic, I understood that what i tought was a little clamp, is this golden "filament" on the botom of the image, joined to cap.

what it is? think on mine is detached.

m0ro0.jpg