Gas gauge stuck at Full

[Chris97K1500]

My gas gauge has always worked fine, but after filling it up last night (was working before the fillup) and then driving 94 miles, it's still at the Full mark. No way that is possible! Usually get to 50 miles and it's already going down. When I start it up the needle goes to just above 3/4 tank, which is about where it should be now, but then moves to the full mark. Just wondering if this is a sign of future fuel pump problems! Thanks, Chris

[MarkD]

Probably a gauge problem instead of a fuel pump problem.

[Chris97K1500]

Just a little update, I went outside and checked out all the connections to the battery no problems. But with the truck off, the gauge reads in between 3/4 and full, when I turn the key it slowly starts to move to above full. If I turn it off, it goes back down to between 3/4 and full. Is there any way to fix this, or is it just something I'll have to deal with? I guess the interesting thing would be if it reads correctly with the truck off, I'll have to watch to see if it drops when off. Thanks, Chris

[sjspor]

The sending unit has gone south. My 97 did the same thing... It will actually go down after a while. After 300 miles It was usally around 3/4's. Just use your trip odometer now...

 

Funny thing about this, this happened under while still under 36K, so the dealer had to deal with it. I guess there was a misprint in thier books, and they changed the PCM first for this!! Ouch...

[k1500chevy97]

Mine has been doing the same thing for over a year . I just use the trip odometer

[Chris97K1500]

Thanks, I just wanted to make sure it wasn't the beginning of something bigger! Chris

[mblrds]

What is known as the Fuel Level Sending Unit to all of us "shade-tree machanics" is known as the Fuel Gauge Tank Unit to GM. The cost of the part alone is $122.00 (should only be about $17.00)! To get the part replaced at the dealer will run somewhere around $400.00! It is my understanding that they are pretty easy to replace, once you drop the tank or remove the truck bed.

[Chris97K1500]

Well now I have a different problem, although it's one I like! After driving this weekend to go camping, the gas gauge started to go down after I went about 140 miles, after 260 miles it had gone down to between 3/4 and a half of a tank (usually it's almost empty at 260). I go to fill it up and I can only put 13.7 gallons in it before it stopped. Turned the truck on, it went back up to full as normal. With this tank full, it's doing the same thing, I've gone 100 miles and it's still just under the full mark. Is it possible that I'm getting almost 19 mpg, after averaging 12-14 since I got it in Feb? Only thing I can come up with to explain this is that I disconnected the battery for about 12 hours when I did the bodylift, could that have reset the computer on the truck? Could that alone make the gas mileage go up 7 mpg? I know the gas tank is full, I over filled it on purpose to make sure, it came running out at 14.3 gallons. This has to be the cheapest mod for an increase in mpg! Disconnect your battery for a few hours.

[diver76]

Chris,

 

Just as a precautionary reply. Here in Canada some GM cars and trucks are having a problem with their fuel gauges. The fuel gauge just stops working.... It will stop at where ever the position it feels. A few people at work have had this problem and according to GM it is a fuel sender that is being damaged from bad gas. GM is trying not to replace but is giving the advice of fuel additive cleaner. They have replaced one persons sender only because she was hounding them. (She is good at that.) I am not sure if this is your problem or maybe it is just the beginning to this problem. I hope it isn't. Thought I should point it out to be safe. I don't know which gas company you fill up with but up here it was Petro Canada and Shell. I don't think you will have a problem with the first, but the latter you might want to look into if you fill up there.

 

Good luck