So it had been about 1500 miles since I had last put any additive in my gas tank, so I went online and found what seemed to be good stuff, its called Techron by Chevron. I went out and bought it, and waited for my tank to get low then added the stuff and went to the gas station and filled up my tank. Whenever I get gas I always leave the battery on, and watch the fuel level rise. Well as the level was rising it all of the sudden dropped to the bottom and said that I had no gas? I pulled the car over to the side after I filled up to put air in my tires and let the car sit for a minute and it seemed to correct itself. On the ride back across town to my house the gauge dropped to empty again. It dropped and rose several times saturday night, and sunday it gave me an accurate reading most of the day of how much gas I had. Today I had no problems with the gauge until about an hour ago when it dropped back to an empty tank again, then rose back up to where it should be. Does anyone have a clue as to whats going on with my car? I've never seen anything like this before. Also before I bought the Techron I made sure that I read the label and it said "safe for all gasoline engines" so im wondering if this is just bad luck or the Techron doing this....

Thanks in advance for your help!

Mat

 

Bump.....does anybody know what this might be?

Thanks,

Mat

 

Sorry for the lack of response, but we'll try to get something going here....

I can definitely say that there isn't any way the additive affected your fuel level sender ... I think it was just coincidence. Some of the techs on here may be able to point you in the right direction to diagnose the intermittent issue with the gauge, but it sounds like a loose wire or faulty sender to me.

There are two level gauges in your tank, a LH and a RH. They just run from the tank to the Rear Electronic Module, so there isn't much room for a problem - you could probably check wiring yourself.

 

From the way you wrote your message, it sounded like you added the Techron to a low tank and drove it to the gas station. Procedure indicates to add it to the tank at the gas station and fill the tank, therefore mixing it with a full tank. Don't know how a high concentrate of the Techron would effect anything on the way to the gas station.

 

hlgeorge,

The gas station is about 1/10th of a mile from my house, so it wasnt like I was driving a long distance between putting it in a low tank and filling it up.

Mat

 

Hi Gents - I have the same issue with my 2004 Vanden Plas, you'll be going down the road and all of a sudden the fuel gauge reads empty and the warning light is on, the trip computer is also non functional at this time as well. The dealership is coming to get the car and will make it's 4th attempt to correct this problem. They have replaced the fuel sender twice, but for some reason this has not solved the problem. A fuel additive should not cause this problem. If they manage to get this sorted out I'll post what the solution was.

A word of caution; they get into the tank via the back seat, make sure they clean up well after themselves or your Jag will smell like gasoline for about a week.

 

There is a module that compares the levels in the two sides of the tank to see to it that the trim pump keeps both sides even, your module may have a bad connection or the module may be bad.

 

The car goes into the dealership to see if they can sort this out tomorrow. I'll mention your thoughts oldmots to the service writer who is about to pull what's left of his hair out over this. Interesting thing happened the other day, an amber check engine light came on for about a day then went out. I'm told that if the car cycles (running - off) two complete times without the error reoccurring that the light will go off, hope the computer stored this code. I'm really hoping that this will somehow lead them to the real cause of the problem.

 

Sounds like one of the floats on your senders is getting stuck. Next time it happens try shaking the car by pushing up and down on the quarter panel and see if the gauge goes back up.. It could also be a faulty ground wire or a bad connection.

 

Just an update.....

I brought the car in last thursday and I spoke to my service manager today and he told me that they were unable to pull any codes from the car, and they cant get the gas gauge to do what it was doing for me. He said that they would try again tomorrow, but even if it does happen tomorrow that doesn't mean that they will be able to make it happen again for the guy from the warranty company because its getting interemittant now for them. I swear every time I get something fixed on the car something else totally unrelated goes wrong!

Mat