My bf drives a Honda Element. Last weekend we filled the tank before floating a river and the gas light came on while driving home (the trip was only 75mi away). We figured the tank got siphoned and chalked it up to bad luck. This was Sunday.
He put 2 gallons into the tank before work today (Tue), and by the time he got to work, his tank was empty again.
No spots under the car at work or in our driveway, no gasoline smell. Does anyone have suggestions about where to look first?
Note - the car has been having some issues. Cat was stolen a year ago and the repair was botched, having various troubles since then (stalling at stops among other things) but lately we got it running at its best since the cat thief… and now this happens
So the gas doesn’t disappear only when parked?
Correct, it seems to have dropped significantly while driving to work today.
The vehicle may be using excess gas due a thermostat that’s stuck open or a bad coolant sensor.
Is the Check Engine light on?
If the oxygen sensor is malfunctioning, the engine could be consuming up to 50% more fuel. Thermostat won’t make much difference during summer months.
Wouldn’t that turn on a Check Engine light?
The check engine light has been on for a long time.
suggest you check the engine.
how far is work? 2 gallons isn’t much. Unless you only have a 5 gallon tank, it’s not even going to measure much on the gas gauge.
I don’t think everything is fixed correctly yet. That’s where I’d start.
2 gallons should get you at least 50 miles or so. Is the drive to work further than that? Is there a lot of black-ish looking smoke coming out the tailpipe? Suggest to ask your shop use their scan tool to obtain a fuel-trim test, shouldn’t be overly expensive. You are welcome to post the results here for more ideas. Many relatively inexpensive aftermarket scan tools allow a diy’er to check the fuel trims themselves as well. Do either of the O2 sensors look like they are coated w/oil or gunk?
Back in my Morris minor days with an obvious engine problem, I filled the ten gallon tank then drove ten miles to the next town. I filled up again to get home. I wouldn’t rely too much on what the gauge says though. My riviera was down to about 16 mpg. I change the o2 sensor and took it for a short drive. I was up to 28 mpg on the computer before getting home. Gas is squirted into the combustion chambers thousands of times a mile so it doesn’t take much to destroy gas mileage.