The last few times I've filled up my 318is with fuel, when I've unscrewed the filler cap I've noticed a massive rush of air into the tank.
Based on what I've read in other forums, I'm guessing there's a problem with the system for equalising pressure in the tank as fuel is pumped out. Maybe due a blocked breather pipe? I've not found any e30/M42 specific info though.
Does this sound the likely cause, or could there be other possible issues?
Note the engine runs fine and the fuel economy is probably the best it's been.
I'm not clear on how the system should work, or which pipes are which on top of the tank, so any guidance would be appreciated.
Rush of air when opening fuel filler cap
Moderator: martauto
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Brianmoooore
- E30 Zone Team Member
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- Joined: Mon Jan 10, 2005 11:00 pm
Does your car have a cat, lambda sensor and carbon canister?
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cheesebox
- E30 Zone Regular
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Hi Brian. No cat or lambda. I guess that probably means no carbon canister.
I've noticed a smell of fuel too when the engine's cold. The tank was replaced recently, but that was a few months ago. The problem only start recently. It might coincide with having the inlet manifolds off to replace the rubber pipes under the TB. Maybe I've disturbed something around the fuel pressure regulator?
I've noticed a smell of fuel too when the engine's cold. The tank was replaced recently, but that was a few months ago. The problem only start recently. It might coincide with having the inlet manifolds off to replace the rubber pipes under the TB. Maybe I've disturbed something around the fuel pressure regulator?
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
The point of entry for air (to replace the fuel used) into the tank is a 8mm bore rubber hose connected to the end of a steel pipe that comes up into the engine compartment at the rear left corner. The open end of the rubber hose should be tucked into the reinforcement structure for the front LH suspension turret.
If you remove the fuel filler cap, pull the hose out of the reinforcement, and blow into it, air should come out of the filler neck.
From what you say has been done to the car recently, a kinked or trapped vent pipe across the top of the tank might be a possibility.
The fuel smell is likely to be a completely different problem. Could be an O ring as you suggest, or something as simple as a hose clip not tight enough.
If you remove the fuel filler cap, pull the hose out of the reinforcement, and blow into it, air should come out of the filler neck.
From what you say has been done to the car recently, a kinked or trapped vent pipe across the top of the tank might be a possibility.
The fuel smell is likely to be a completely different problem. Could be an O ring as you suggest, or something as simple as a hose clip not tight enough.