2003 Gas Guzzler

[dhunters4life]

I only drove 55 miles since my last fill up and it is already showing past 3/4's of a tank. For some reason the gas gauge fluctuates and just really annoying to see this when I know I should be getting a lot more miles out of a tank. Can anyone give me some suggestions for problems?

much appreciated

[topless kitty]

don't base mileage on the gauge like that. wait until you're near the end, fill up, and calculate mileage based on how many gallons it took. that's the only way to accurately determine.

[vdubbugman53]

car run poorly or smell like gas?

[dhunters4life]

Originally Posted by vdubbugman53

car run poorly or smell like gas?

It seems to run fine and doesn't smell like gas at all. There's no leaks, no spotting on the ground, nothing looks wrong at all.

[Smileybug]

I would say don't judge your gas mileage from the gas gauge. Wait until you fill up and calculate your mileage by hand (miles traveled on the tank/gallons put into the car). The gauges can be pretty flaky. I have gotten 230 miles to the half tank line, but then have to fill up at 350. (230 at half-way would assume you get 460 miles on a tank, if the gauge was completely accurate). I have never had my gauge read that low at that point but again, don't judge it yet.

[dhunters4life]

i never got 460 to a tank, but in 30miles for the gas gage to even be touched, that doesnt sound right it should be still at least lil past the full mark

[Smileybug]

Have you had this car for awhile or is it the first tank you've run in it?

[SMG]

How's the idle? Could be as simple as a vacuum leak which would most times give you a rough idle.

It could also be a bad MAF or O2 sensor.

[dhunters4life]

it idels fine, doesnt idle rough or anything

[dhunters4life]

acualy, i do have a problom with the cooling system not sure if that ahs anything to do with it

[cep]

What kind of problem with the cooling system? It can have an effect.

If the ECM 'thinks' the engine is cold, it will continue to richen the mixture just like it's supposed to do for a cold engine even though the engine is hot. Telltale signs of this would be blackened spark plugs and soot inside the tailpipe. If I'm not mistaken, the coolant temp sensor is what provides the ECM the info it needs to tell whether the engine is warm or cold. It is a cheap part and easy to replace; I think I'd try that first.

Second on the list are the Oxygen sensors. I believe they make inputs that are used to help the ECM decide on what mixture to send to the engine.

[dhunters4life]

P2181, Cooling System Performance

[cep]

A bad coolant temp sensor or thermostat will cause a Cooling System Performance code.

[dhunters4life]

soare you sure cause im limited on time now and i gotta get it fixed, everyone is syain that the code throws off multiple issues, ithey never specified if it was one thing or not

[cep]

My advice is worth what you paid for it.

What have you got to lose by changing the coolant temp sensor? It's a ~$20 part that takes a couple of minutes to change.

[cep]

One more question: Do you have a lot of foamy looking crap on the underneath side your oil fill cap? If so, you probably need a thermostat. If not, coolant temp sensor.

[dhunters4life]

the foamy stuff no, so the coolant temp sensor will trigger the check engine light too? which the check engine light will lead to the coolant temp sensor imma presume right? sorry im not all technical with cars like this

[Smileybug]

I never got a CEL when my temp sensor was bad, but I did throw a code for it, and I have seen many people on here get a CEL when it goes.

[SMG]

I never got a CEL from a malfunctioning coolant temp sensor either.

[cep]

Yeah, come to think of it, ours did not light the MIL, either...but the code was there to be read. We discovered it when the airbag light was on.