That whacky gas gauge!

KirbyLW · January 27, 2004

My gas gauge has developed a case of MPD (Multiple personality disorder)!

Assume I just stopped and filled the tank.

I turn the ignition on and the gauge just sits there on E. Then it jumps suddenly to FULL. Then it jumps back to EMPTY and the "Low Fuel" light comes on. Then it changes its mind and says, "well, OK, maybe you have half a tank." Then it might fall back to E and start CREEPING up slowly, taking five mins to reach FULL. Stays there for a while, gets tired of that reading and goes for the quarter tank mark. Then a quick dart back to E (I guess it just likes reading the "Low Fuel" message) - back to Full.. no wait...

You get the idea...

Is this a tank sensor problem, or a problem with the gauge itself? I was thinking of running a can of B12-Chemtool through the gas tank in case the sensor was getting gummed up. But this would only explain slow, or nonexistent UPWARD movement of the gauge needle, and wouldn't really explain the downward movement of the needle. Or would it?

Any takers?

Kirb

January 27, 2004

I'm going to bet on a loose/corroded connection to the sensor. I believe the low fuel light and the gauge are independant responses to the sensor, hence, if you get a fuel light and a bad reading at the same time...............

TROYROBO · January 27, 2004

sgiangregorio · January 27, 2004

Sounds like the sending unit is either going or has a bad connection. My 2002 Z71 Tahoe had a problem over the last few years a couple of times. I brought it to the dealer and they replaced it under warranty (the fuel pump and sending unit is one piece).

c5vetteman · January 27, 2004

Sounds like the sending unit is either going or has a bad connection. My 2002 Z71 Tahoe had a problem over the last few years a couple of times. I brought it to the dealer and they replaced it under warranty (the fuel pump and sending unit is one piece).

Yep, I had the proverbial erratic fuel gage symptom and the dealer replaced the fuel sending unit and it took care of the problem. Luckily. I had an extended warranty that took care of the cost!

Chuckster · January 28, 2004

This is a common problem with the C5 Corvette.. Some have had the guage replaced only for it to come back again..

Seems it comes from the reaction of many different type of gas and it forms a corrosion on the rheostat on the sending unit.. I saw one being removed frmo a C5 at the dealer.. It lools like a black carbon gritty sand on the contacts..

You may want to drive the truck till the gas reads very low.. Then put 2 bottles of techron in the tank.. Then take the truck on Mr. Toads Wild Ride... Slosh the Crap out of the gas/techhron mixture that is in the tank.. You just may be able to rinse it clean...

After seeing the Vette guage it looks like it could just be cleaned