MPG drastic drop

[HDhillon]

About a month ago i removed my Dr. Performance, so i have been running stock for a while. I commute a little over 50 miles a day and the past two weeks i have been seeing horrible fuel mileage. Today i burned a hair less than a quarter tank and only went 58 miles. Does this sound normal or is something wrong? I have 34,000 miles on it and haven't had any problems yet. Engine noise has also been louder recently. Any thoughts or suggestions?

 

[CLAYTON]

Could be a fuel filter.

 

[mberry]

Fuel filter or air filter. How's your power been? When was the last time you changed the oil?

 

[bpenrod]

Have you checked the oil level? Could be a leaky injector, bad fuel mileage and it would be cutting the crank oil with diesel fuel. Pull the dipstick and see if it is over-full.

 

[nickleinonen]

Have you checked the oil level? Could be a leaky injector, bad fuel mileage and it would be cutting the crank oil with diesel fuel. Pull the dipstick and see if it is over-full.

i was thinking the same...

 

[Heavyweight]

You are under warranty,,,, Take her in...

 

[HDhillon]

I checked my dipstick today (several times) and the oil level was about an inch or so past the "safe" area. This means i should take it in and tell the dealer???

 

[2Gen3Gen]

I checked my dipstick today (several times) and the oil level was about an inch or so past the "safe" area. This means i should take it in and tell the dealer???

Sounds like you have diesel in your oil. . Take it in but I highly suggest that you remove any mods that would void any chance for D/C to VoID your warranty.

 

[bpenrod]

I would get it in there soon! I have read some posts on here where the injector fails bad and fills the crankcase!!

 

[HDhillon]

Would DC void my warrenty because of the missing muffler???

 

[JRD]

typically a missing muffler wont void the warranty. But if they wanted to get real strict, I guess they could try to void it... When we say remove your mods, we are talking about fueling boxes and the like. If you had an after market intake system and still had the stocker laying around you may want to swap the stocker back on just for the heck of it.

 

[HDhillon]

Thanks for the advice. To keep you guys updated, i took her in and the dealer said the oil level was fine. They told me i was on uneven ground. As far as the mpg issue, they told me they cant check anything until the check engine light comes on. Although they do offer a program where three of the service techs drive my truck 200 miles each (I pay for fuel) and see if they notice anything.

 

[Badunit]

That's an interesting program: 600 free miles of driving for their service techs. I bet they'd find a low mpg problem a lot sooner if they were paying for the fuel.



(58 miles)/(1/4 tank) = 7mpg.



($3/gal) *(600 miles)/(7mpg) = $257 for the privledge of the maybe getting three techs to agree that the mpg is low. Not to mention that they might treat your truck in ways you wouldn't want it treated.

 

[rbattelle]

Thanks for the advice. To keep you guys updated, i took her in and the dealer said the oil level was fine. They told me i was on uneven ground. As far as the mpg issue, they told me they cant check anything until the check engine light comes on. Although they do offer a program where three of the service techs drive my truck 200 miles each (I pay for fuel) and see if they notice anything.

I can't imagine how uneven the ground must have been to indicate a full 1" over full. Did the oil smell like diesel? If their attitude is that they can't do anything until a MIL comes on ( ) then just drive it and wait for it to explode.



-Ryan

 

[LSteiner]

I'm thinking you should fill it up to check 'actual' fuel used.



I've read where some have noticed erratic fuel gage readings.

 

[hERKY130]

I have the same problem, I have quadzilla on 100 all the time, I don't step into it a lot. I just use it for the mileage so I thought. Display says 21 and hand calculated mileage is 15. I drive 60 to and from work about 15 miles each way and I don't hammer at all to pass and the like. I pulled the dip stick and it too was about an inch or so above full and oil was jet black. I still have 2000 miles left before I change the oil at 7500 mile interval. I have 13000 on the clock so I'm lost. I used to get hand calculated around 21-22 on highway with the quad on full and then I had a box malfunction. I had it replaced and it has slowly been getting worse mileage. What do you all think?



Chris

 

[CoastyAV8R]

If your truck is "making" it's own oil, I would say you either have a problem or the proverbial goose laying the golden egg. I would venture to bet with the rest of the fellas, you have a leaking fuel injector that is causing the increase in your engine oil level. Smell it and see if you can smell diesel fuel in your engine oil.