Thread: fuel loss

I have a 1998 Pontiac V6 Grand Prix 3800. It takes $36.00 to fill it with gas mid grade. It takes two days for the gas to run out. I have 112,000 miles with this car. I did a tune up and I have done fuel injector cleaning. I notice on my dash monitor showing low percentage in fuel consumption. Can anyone suggest a solution to this problem ? , How can I set the reset monitor showing the low percentage ? and I did a coolant flush and my low coolant indicator came on. How do I correct this problem?

janiuay123

First off the low coolant sensor pisses me off! That thing is junky stuff and always takes a sheeeiat. But seeing as if your's showed up after you did the coolant service means that you prolly didn't get your system filled properly. First off does your temp gauge seem to be running colder than before? Prolly wont matter either way, because I believe your e.c.m reads the coolant temp sensor to determine the coolant temp. Now if you didn't get the sytem filled correctly your coolant temp sensor may not be seeing the right coolant temp therefore it will run in rich mode to heat up and give you bad gas milage because it is constantly in open mode operation in order to heat up the engine. What you need to do is purge the system of air and get it filled up properly. What I do is fill it up at the radiator cap and start the engine with the cap off, and add coolant till you can't add no more, pump the upper radiator hose a little bit, (don't worry if you spill it's only coolant) hehe
now don't be sceared you need to run it till the thermostat opens so you can properly fill the system. Once it opens it will either start bubbling out the radiator cap or suck way down in which case fill the f er up and close the radiator cap and post back from there. (by the way a properly functioning thermostat will take a few minutes to open, it will be close to operating temp on your gauge before it opens)

and yes I do realize that was terrible half askes advice, but it may shed some light on the subject

Originally Posted by UR LOSN

do a manual check on your mpg. Is your car running completely out of fuel? the gauge is not always accurate....

if you go into the DIC fuel screen. press and hold reset button until it clears it out.

I would carry a gallon of fuel in your trunk and physicly see how far you can go on your tank of gas. I would allow the gauge to go all the way down past the E. this will also tell you if your fuel gauge is accurate of not. in which case you would need a new level sensor in the fuel pump assembly(easy fix).

36dollars to fill up? wow!!!!!!! I just put in 52dollars today...

by saying that...it might tell me that your fuel pump is not using all the fuel out of the tank....

agree 200% for $36 in even my buick I can't get but 12 gallons or so