Gas gauge indicator goes to empty when full

SOURCE: fuel gauge

khooper, in another forum, told me that "Chevron Techron Fuel System Treatment Plus can remove harmful sulfur deposits from the sending unit and a filmer agent that can prevent the deposition of said sulfur"

My 05 Trailblazer LT 2WD.
Erratic readings, and when the fuel level was below 1/2 full, the needle would sit on "Empty" with the amber light staying on.

So I went to a dealer, they replaced the fuel level sensor (p/n 19177712 SEN KIT 3.107 $118.62) with labor $270.00 for a total of $398.86 this appears to have fixed it for now.

I also talked to another mechanic who blames ethanol for these deposits !

SOURCE: When the gas tank is full the gas gauge shows as

Well that tells me that someone installed the wrong fuel level sensor. Your going to have to drop the tank and pull the pump and float assymbly out. Then go to a parts store and get a sending unit that has the opposite resistance of that sending unit. Just wait until the tank is empty so its a lot lighter. You can call the parts store or go down and see if there is multiple sending units. The sending units work by resistance, when the tank is full the float moves up and turns a wheel in the sending unit, which either removes or increases the resistance causing the gauge to lower. The sending units either give full resistance at full or no resistance at full and then changes as the level goes down until it does the opposite at empty.

SOURCE: gas gauge malfunction and engine light stays on

This is a common problem with Malibu's. It is due to cheap metal in the fuel gage that corrodes. Chevrolet knows about this but they refuse to issue a fix. The check engine light staying on and the faulty fuel gage are related. This is a defect and they need to recall this part! Raise hell with the dealership!

SOURCE: my car fuel level gauge sometimes goes to empty

Mine too! I have a 2007 Chevy Malibu also and I knoticed it does that or bounces up and down once my tank gets to half full. Have you found a solution? Sometimes my check engine light comes on and sometimes it doesn't.

SOURCE: gas gauge goes up and

You most likely have a failing fuel level sending unit which is located inside the fuel tank. The sender wears a bit as the float arm moves up and down with normal fuel level variations and this wear can result in a guage that reads erratically. Many of the fuel level senders are now only sold as a part of the fuel pump module so if it turns out that it is indeed the sender you may have to replace the entire pump module. Hope this helps!