I noticed 3 weeks ago that when I opened the filler cap to gas up, there was no sucking sound. So, my system is no longer sealed. At the same time I also noticed a raw gas smell anytime the windows or sunroof were opened. It's not the usual seal issue with the hatch letting burned fuel exhaust in.
Replaced gas cap. No change. I pulled the cover and carpeting to expose the filler and other various tubes. I couldn't see any tears. Tightened all clamps. No change. I checked the fuel gauge sending unit and it's gasket. All fine.
So, yesterday I decided to remove the passenger rear wheel (that's where the raw gas smell is the strongest). I jacked the car up with the wheel removed. I took off the cover panel for the fuel pump, hoping I'd see wetness. Nothing. The fuel pump is fine. SO what the HECK could be leaking?!
With the car jacked up and the passenger rear wheel removed, I inserted a funnel and began filling the car slowly. My hope was to get some fuel to leak and see what the issue could be. Well, I got the fuel to leak and it’s a very sizable leak! The problem is that I can't see what is leaking! The leak seems to be coming from the top of the tank, which of course is not visible without removing the torque tube and transaxle and dropping the fuel tank. I've looked at the schematics on AutoAtlanta's website and man I just can't see what the issue is. It’s not a drip. The fuel was running out at a very good clip.
Here is my question. If I filled the tank to overflowing, where would the fuel begin to spill from? Would it simply fill up into the fuel filler neck area you see when fueling and then out and down the small drain tube? I've checked mine and it's fine plus it wouldn't account for the lack of vacuum in the tank when gas is used. My guess is filling the tank and running it down to ¼ tank has made enough vacuum that some almost 20 year old plastic or rubber part surrendered and is now leaking. Since the tank is plastic and hasn’t been damaged, I find it hard to believe it split somewhere.
ANY ideas as to what it could be are greatly appreciated. I just can’t afford right now to pay to have the tank dropped.
I would guess that you have the dreaded cracked vent hose. If you look at the schematics, there are a couple of vent tubes that are hard to get to that run across the top and side of the tank and connect to the carbon canister.
I've got the wheel off again and tonight will look closer to see if I can tell where the leak might be coming from. It's definitely high up because I only got a physical leak once I topped it off with the funnel. Thank you for the suggestion. I will check it out.
There is also a chance it's the sending unit or the sending unit gasket. These sending units are known for cracking around the vent tubes, and the gasket has been known to shrink and fail as well. Try looking through the inspection hole in the floor of the trunk to see if fuel is coming out around the sending unit.