# 1999 Pontiac Grand Prix \_ I wish it were true, but

**URL:** <https://community.cartalk.com/t/1999-pontiac-grand-prix-i-wish-it-were-true-but/123808>\
**Category:** Maintenance/Repairs\
**Tags:** pontiac\
**Created:** [August 27, 2018, 4:16pm UTC](https://community.cartalk.com/t/1999-pontiac-grand-prix-i-wish-it-were-true-but/123808 "2018-08-27T16:16:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![JohnPitcher](https://avatars.discourse-cdn.com/v4/letter/j/c37758/32.png) [@JohnPitcher](https://community.cartalk.com/u/JohnPitcher)\
**Post date:** [August 27, 2018, 4:16pm UTC](https://community.cartalk.com/t/1999-pontiac-grand-prix-i-wish-it-were-true-but/123808/1 "2018-08-27T16:16:53Z")

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fuel gauge periodically reads full when the tank is not full

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**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\
**Post date:** [August 27, 2018, 5:52pm UTC](https://community.cartalk.com/t/1999-pontiac-grand-prix-i-wish-it-were-true-but/123808/2 "2018-08-27T17:52:51Z")

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That means your fuel sender is failing. It is in the tank and I think, part of the fuel pump assembly. You might try a bottle of Techron (read the instructions) in with the fuel to clean it off. Given the car’s age, and possible mileage (100K +) it might make sense to change the fuel pump before it fails and get 2 birds with one stone.