[tommygrubb2001]

Gas milage is horrible. I drove 9 miles and dropped quarter of a tank. I have a 2001 v6 with 119,000 miles. The milage has got worse and worse now is horrible I replaced plugs 5000 miles ago, new cool pack new fuel filter, new air filter, what gives.. Idk what else it could be help is much appreciated

 

[99mustang99]

Gas milage is horrible. I drove 9 miles and dropped quarter of a tank. I have a 2001 v6 with 119,000 miles. The milage has got worse and worse now is horrible I replaced plugs 5000 miles ago, new cool pack new fuel filter, new air filter, what gives.. Idk what else it could be help is much appreciated

Idk may could be a fuel pump issue, never had a problem like this, I'm sorry to hear it bro

 

[tommygrubb2001]

How could a fuel pump make a car use more gas normally it causes the car to use less and die and not start

 

[99mustang99]

How could a fuel pump make a car use more gas normally it causes the car to use less and die and not start

Just throwing out options, small fuel leaks signs at all?

 

[1slosix]

check the filler neck grommet at the tank

 

[Redstang19]

I had this problem, my fuel injectors had a lot of carbon covering them, once I ran some injector cleaner through the tank it got better again. Try it and see what happens.

 

[tommygrubb2001]

I have tried seafoam to clean the injectors about 4 times, and I will check to grommet in a few minutes, and I can't smell gas or see any gas on the concrete after it sits there? So I don't think it is a fuel leak

 

[Redstang19]

When I had a brake sticking a little my gas mileage was really bad, maybe you have one sticking and haven't found out yet?

 

[fastmustangs1]

Are you running a stock tune or performance tune on ur car?

 

[Xaperez100]

I had this problem the other day but it wasn't really lowering my mileage it just said I was. My low fuel light came on after driving about 3 miles from half a tank. But it went away a little while after.. It was weird. Then I ran some supreme fuel in there and fuel cleaner and my car runs better and is better on gas. The mileage was just an electrical error I'm guessing because it went back up to half a tank. And I wasn't on a hill

 

[tommygrubb2001]

I have replaced both two from calipers and brakes the front should not be sticking the back may be? And it's bone stock, except the dual exhaust could cataylic converters do this? Bad o2 sensors?

---------- Post added at 11:20 PM ---------- Previous post was at 11:20 PM ----------

What is a good fuel system cleaner that works?

 

[99mustang99]

I use the fuel additive zmax makes and it's always been good for me

 

[davidcseifert]

Don't trust the gas gauge, fill up and divide the miles driven by gallons used.

Also, if you really have that bad of gas mileage, how's the car running? Notice any oil in coolant, or vice versa? Blown head gasket would cause really bad mileage but has symptoms you should be able to spot easy.. I say this because head gasket issues are somewhat common on these cars

 

[tommygrubb2001]

No coolant in oil or vice versa, there is a god awful tapping noise almost like a exhaust leak coming from under the car. Tranny is acting up? And feels so bogged down. I want to keep this car but its very sick

 

[Ghostedmind]

when you did the seafoam, did you notice any smoke at all coming from under the hood? that was how i found an exhaust leak (the tapping) if no exhaust leak the it sounds like you might have a rod knocking, which could be a bearing going bad, you need to try to pinpoint the knocking sound a little better than just under he car if you can. if you're saying it sounds like an exhaust leak it may be a bad piston ring. With the information I've seen so far there's a good amount of stuff that it could be.

 

[tonyd01gt]

No coolant in oil or vice versa, there is a god awful tapping noise almost like a exhaust leak coming from under the car. Tranny is acting up? And feels so bogged down. I want to keep this car but its very sick

hi, what is the tranny doing? you stated acting up, is it a auto or 5spd? if the tranny is slipping you will have bad gas mileage.

 

[Dantheman94]

Vacuum leak somewhere?

 

[tommygrubb2001]

The tranny is auto, and the exhust leak is more pronounced under the drive side towards the front. I did sea foam
The car and it did smoke I seen no visible smoke in the engine bay, I have seen any forums saying it may be a exhaust leak how would one check?

 

[Crowned1]

Don't trust the gas gauge, fill up and divide the miles driven by gallons used.

Also, if you really have that bad of gas mileage, how's the car running? Notice any oil in coolant, or vice versa? Blown head gasket would cause really bad mileage but has symptoms you should be able to spot easy.. I say this because head gasket issues are somewhat common on these cars

I'd agree with not trusting your gas gauge. After driving my car sometimes the gas gauge will lower then come back up a couple of minutes later. I know a lot of others who have had this problem as well.

 

[BloodRedStang]

I'd agree with not trusting your gas gauge. After driving my car sometimes the gas gauge will lower then come back up a couple of minutes later. I know a lot of others who have had this problem as well.

I don't trust any of the gauges in mine.. oil pressure gauge says pressures too high, but it was a quart low.. temp gauge says its overheating, but its not. Gas gauge says I have a little over. 1/4 tank, but I just put 11 gallons in. Voltometer dances with the beat of whatever music I'm listening to.. you get the idea.. lol

Your cars a new edge right? Check for a cracked exhaust header, may explain the tapping sound. or an exhaust rattle but I think that would change from rpms. Also, might wanna check your cats, could explain it running rough and crappy mileage.