Thread: Z3 Fuel smell in boot
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Old 10-02-2012, 08:55 AM
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Randy Forbes Randy Forbes is offline
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Originally Posted by dkindig View Post
The key phrase is that there are no leaks visible.

There is an extensive network of vapor recovery tubes that run on top of the fuel tank and those have been known to be a problem. Also, if there has been any aftermarket audio work done it isn't uncommon to see an installer actually drill into the fuel tank while drilling holes for screws.

Unfortunately, to make a complete evaluation of fuel vapors coming from that area the best way is to break down and pull the fuel tank for inspection of the tank and associated lines.
Actually, this symptom can be evaluated very quickly and easily by performing a "smoke test" saving at least ten (>10) hours of dismantling the back half of the car. Using a smoke generating diagnostic tool, you can locate vapor leaks in a matter of minutes, and I've done so for just the reasons you've pointed out (stereo installers drilling into the tank's chambers and also rodents chewing on the maze of plastic tubing).

A very cool tool, and kudos to whoever thought it up__though I suspect it's an age-old practice, as I can remember guys in the 60s exhaling their cigarette smoke into the vacuum line to see if the distributor advance diaphragm was cracking.

Originally Posted by Nezy76 View Post
Just letting you know the update on my car. Had it looked at, turned out to be the drivers side fuel tank strap was loose. Cheap replace 13 from dealer.
Thanks again for the input. Great forum
Yes, they can work loose, or the rubber insulating pads become dislodged, but I still can't see how it led to your smelling fuel in the trunk; the fuel tank is a sealed unit (and it's tested everytime you start the car via a small pressure pump). That's why you get a check engine light if you leave the filler cap off/loose.

If you didn't get a check engine light, resulting from a system breach, then there shouldn't have been any smell. I think you're just psychic and that's what led you to getting the loose fuel tank strap taken care of...

Randy Forbes
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