Very strong petrol smell in car

[Hammer278]

Been having this issue for a few years. I understand this is a common issue with the model, but the smell has become unbearable the past 2-3 weeks. Especially when I'm idling in traffic and aircond is on at high. Anyone know which part in the engine compartment needs to be replaced and what's the cost like?

 

[alantiong]

check fuel line. there is a short piece of flex hose between the pressure line from under the car to fuel rail. this piece always fail and its located just near the cabin air intake filter .

i suggest change all rubber fuel hose and hose clamps that you can see. there will be some hoses in he fuel tank too.. total should be 2-300 bucks

 

[Roberto]

Is this hose in the engine bay? To the right of the throttle body and a little under the intake manifold, for an M50 engine?

My car always smells of petrol right after a full fillup. I always fillup right to the top of the cap. Is this normal? If not, what do I need to fix?

 

[Hammer278]

check fuel line. there is a short piece of flex hose between the pressure line from under the car to fuel rail. this piece always fail and its located just near the cabin air intake filter .

i suggest change all rubber fuel hose and hose clamps that you can see. there will be some hoses in he fuel tank too.. total should be 2-300 bucks

Hey thanks, this helps very much!

 

[Iylia H]

Is this hose in the engine bay? To the right of the throttle body and a little under the intake manifold, for an M50 engine?

My car always smells of petrol right after a full fillup. I always fillup right to the top of the cap. Is this normal? If not, what do I need to fix?

Open your boot, and open the fuel pump hatch. If it's wet there, you might have a cracked rubber hose or worse a cracked at the fuel pump's top plastic cover. Either way, you need to get it change, because fuel will leak through evaporation even when the tank is not filled to the brim.

 

[Iylia H]

Been having this issue for a few years. I understand this is a common issue with the model, but the smell has become unbearable the past 2-3 weeks. Especially when I'm idling in traffic and aircond is on at high. Anyone know which part in the engine compartment needs to be replaced and what's the cost like?

Had this issue once during the early stage of my ownership. Mine was due to one of the fuel injectors gone bad. Changed it, problem solved.

 

[alantiong]

Is this hose in the engine bay? To the right of the throttle body and a little under the intake manifold, for an M50 engine?

My car always smells of petrol right after a full fillup. I always fillup right to the top of the cap. Is this normal? If not, what do I need to fix?

oh this is an easy one. if you have smell after filling up, then the breather hose at the fuel tank is busted. i had that on my E32. its an L shape 16mm OD. 10mm ID hose. no need to buy bmw ori hose. bloody expensive. just any hose will do. i used the blue silicon hose, which i feel is far superior to rubber hoses. but make sure there is no kink in it after install so that it can breath.

 

[anakin]

Hi Alan...what if it smell only during first engine start for the day...?

 

[alantiong]

from engine

Hi Alan...what if it smell only during first engine start for the day...?

from engine bay. hose near the fuel rail.. i have that on my 38 right now.. and abou tto fix it. once i do that.. i can tell u more if my guess is right

 

[alantiong]

but for E39, there is a clear hose with spiral spring like thingy in it balancing the both HUMPs of the fuel tank. u can see when u remove the rear seat bottom . that need to be change at this age of the car.

 

[Roberto]

oh this is an easy one. if you have smell after filling up, then the breather hose at the fuel tank is busted. i had that on my E32. its an L shape 16mm OD. 10mm ID hose. no need to buy bmw ori hose. bloody expensive. just any hose will do. i used the blue silicon hose, which i feel is far superior to rubber hoses. but make sure there is no kink in it after install so that it can breath.

Hi Alan,

Sorry just saw this.

1. A question. If I can smell petrol right after a full fillup (right to the brim fillup), doesn't it mean that the breather hose is working? As in, there's alot of petrol, so there's alot of vapour, and so alot of vapour escapes the car, so you can smell that?

2. Where is the breather hose located on the E34 and how do I change it ? Is it an easy DIY ?

3. Instead of the breather hose leading out the outside of the car - can we feed a long thin hose from the breather to the engine, and stick it into the airbox or intake manifold or something - so that the fuel vapours are not 'wasted' ? The E34 did not come with a vapour recovery system - I think that came with the subsequent generation.

Thanks.

 

[alantiong]

Hi Alan,

Sorry just saw this.

1. A question. If I can smell petrol right after a full fillup (right to the brim fillup), doesn't it mean that the breather hose is working? As in, there's alot of petrol, so there's alot of vapour, and so alot of vapour escapes the car, so you can smell that? The breather concept is to let trapped air to release itself near to inlet which is still technically in the tank, when u close back the cap, it should be closed and no smell. but now the breather hose is leaking, causing a non closed loop. so even cap is closed, the pressure and movement from fuel line will cause fuel to spill out from this point. hence .. the smell.

2. Where is the breather hose located on the E34 and how do I change it ? Is it an easy DIY ? I will not suggest DIY this as dropping the fuel tank, needs a few pairs of hand. yes you need to drop the tank and disconnect the fuel line to get to this. its located near the filling inlet


3. Instead of the breather hose leading out the outside of the car - can we feed a long thin hose from the breather to the engine, and stick it into the airbox or intake manifold or something - so that the fuel vapours are not 'wasted' ? The E34 did not come with a vapour recovery system - I think that came with the subsequent generation. by now you should noticed Breather hose is located at tank and it is closed loop in the tank.

Thanks.


Breather is actually to let the bubbles created when flow comes into tank to rise without choking the path of fuel flowing in from nozzle when filling up.

 

[Roberto]

Thank you for your reply Alan but your description is really vague and imprecise. I've not seen this hose myself and cannot use your description to firm the correct picture in my mind. Do you have a diagram or link that would help ?

 

[Roberto]

Perhaps you can help me out with specific references to the following diagrams :

Fuel supply general :

http://www.realoem.com/bmw/partgrp.do?model=HB62&mospid=47370&hg=16

Fuel tank :

http://www.realoem.com/bmw/showparts.do?model=HB62&mospid=47370&btnr=16_0041&hg=16&fg=05

Fuel supply, ventilation :

http://www.realoem.com/bmw/showparts.do?model=HB62&mospid=47370&btnr=16_0103&hg=16&fg=10


And it looks like this diagram is useful to understand how the two above connect to each other :

http://www.realoem.com/bmw/showparts.do?model=HB62&mospid=47370&btnr=16_0078&hg=16&fg=10



Sorry to be such a pain but I must understand this. Thanks Alan.

p.s. Also would like to know if things will get worse and how, if this problem is left unfixed. Thanks.

 

[alantiong]

Yup yup hose no 3 n 4

 

[alantiong]

Infact I will suggest change all as when u remove the tank.. some other will crack too

 

[Roberto]

Yup yup hose no 3 n 4

Which diagram bro ?

Are you talking about this one ?

 

[alantiong]

3 and particularly 4 in this diagram

Which diagram bro ?

Are you talking about this one ?

 

[Roberto]

Hi Alan,

I checked with my mechanic on this subject. He says there is no need to drop the main fuel tank to access those cracked hoses between the tank and the air escape reservoir. All you need to do is to :

1. Remove the rear right wheel
2. Remove the inner arc-shaped fender cover

and you'll be able to see everything and can fix it. The job should take close to an hour.

Please comment if this is correct. Thank you.

Roberto

 

[alantiong]

maybe E34 and E32 are different.