# 2005 gmc envoy oil gauge **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [October 27, 2015, 8:56am UTC](https://community.cartalk.com/t/2005-gmc-envoy-oil-gauge/91555 "2015-10-27T08:56:55Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Bleh](https://avatars.discourse-cdn.com/v4/letter/b/dec6dc/32.png) [@Bleh](https://community.cartalk.com/u/Bleh)\ **Post date:** [October 27, 2015, 8:56am UTC](https://community.cartalk.com/t/2005-gmc-envoy-oil-gauge/91555/1 "2015-10-27T08:56:55Z")
2005 gmc envoy sle When I fuel up my oil gauge goes up i.e. 1/4 tank = 42 on oil gauge 1/2 tank = 80 on oil gauge and fuel mpg goes down as oil goes up, any ideas as to a cause? ---
**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\ **Post date:** [October 27, 2015, 4:19pm UTC](https://community.cartalk.com/t/2005-gmc-envoy-oil-gauge/91555/2 "2015-10-27T16:19:51Z")
Sounds like a cluster issue. A scan tool will be most helpful at this point to see if the data matches what the cluster shows. Data is fed to cluster via modules, whether it be BCM or PCM. If data agrees, try unplugging connector at alternator and see if it straightens out. I say alternator because it might have a problem causing it to put out AC voltage instead of DC voltage which car electronics are much happier with. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [October 27, 2015, 5:51pm UTC](https://community.cartalk.com/t/2005-gmc-envoy-oil-gauge/91555/3 "2015-10-27T17:51:30Z")
Faulty ground connection to or in the cluster.