MPG SUCKS!!!

[Joshua Peterson]

I have a 2014 1500 Sport 5.7. Within the last 2 months by average MPG have gone from 11.5 to 9.5. Here within the last week it has gone to 8.6. I Mainly do city driving and haven't done anything differently. I haven't added anything to the truck, drive it the same as I always have, and same routes. Take kids to school, go to work, use q few times a week for work (not hauling anything), pick kids up and home. No check engine lights either. Curious if anybody else has ran into this issue or may possibly know of any causes I could start looking in to. Thanks in advance

 

[bgenlvtex]

"winter blended fuel" brought to you by (insert favorite bogeyman here)

"it's not a flaw, it's a feature!"

 

[Daw14]

Have you looked for codes ? Have you checked the torque of your intake manifold bolts , they should all be 108 inch pounds . 5/16” or 8mm is the size.

02 sensors are not a lifetime part.

Spark plugs should be replaced at 100,000 miles.

Routine maintenance ? Air filter ?

 

[Adamcr68]

I have a 2014 1500 Sport 5.7. Within the last 2 months by average MPG have gone from 11.5 to 9.5. Here within the last week it has gone to 8.6. I Mainly do city driving and haven't done anything differently. I haven't added anything to the truck, drive it the same as I always have, and same routes. Take kids to school, go to work, use q few times a week for work (not hauling anything), pick kids up and home. No check engine lights either. Curious if anybody else has ran into this issue or may possibly know of any causes I could start looking in to. Thanks in advance

I would add any details you could, mileage & maintance that you have done or had done such as spark plugs or throttle body.
There are lots of members here that are happy to help & know a lot more than I do regarding our trucks.

 

[Burla]

Try a tank of 91 and report back. Winter gas = less mileage, we are the lucky ones who feel it more then others like people who drive priuses. Technical term winter gas has less energy in it, which is the science of the why.

 

[Adamcr68]

Have you looked for codes ? Have you checked the torque of your intake manifold bolts , they should all be 108 inch pounds . 5/16” or 8mm is the size.

02 sensors are not a lifetime part.

Spark plugs should be replaced at 100,000 miles.

Routine maintenance ? Air filter ?

You just verified my post perfectly!

 

[olyelr]

Yea, thats terrible for a half ton. My power wagon gets down around there in the winter, but my half ton is always up around 15/16 in the winter, and thats when driving like an ******* lol

Something is wrong.

 

[Burla]

So I didn't say why 91 in theory could fix this. So 91 octane "means" it can resist combustion more then 87 or 89, that's a fact. Plus, winter gas can combust easier then summer gas, that's a fact. So now the theory part, if then statements apply, if 91 resists combustion and if winter gas combusts easier THEN 91 octane would allow winter gas to combust in a manner closer to summer gas. BTW, I threw a hail marry at my truck I have to chose 87 or 91 even though I prefer hemi tuned 89, and it totally worked. For the first time I was under 10mpg, and it went to 14 with 91 no lie. I am overdue for a tune up that should have happened this summer but I had three fences on the property fall at the same time within a month, lol. So it will be a while before I find if maintenance is the issue, but whatever octane fixed it for now.

Still riding fence this guy, almost all buttoned up.

 

[express2014]

check for dragging brakes. My 1500 will make 14 MPG.

 

[62Blazer]

Did you just get the truck within the last year, meaning you haven't seen a change in seasons and winter gas yet? What is weather like in your location? Has it gotten drastically colder recently?

 

[Joshua Peterson]

Apologies for the lack of details and I will go ahead and say that I have failed miserably regarding maintenance but really trying to get back on it.
I've had the truck for about 5 or 6 years now. Mileage is at 124,000. I've changed the air filter but it's been awhile. Haven't done the spark plugs (I know and I'm ready the **** I deserve lol). I've had to replace the bolts and have the manifold resurfaced 3 times now. O2 sensors replaced 2 years ago and no codes come up.
Complete honesty, I'm ignorant when it comes to working and maintenance on my truck besides oil changes. Any guidance as far stuff I need and should have done is greatly appreciated and I can always watch videos on how to do things.

 

[Jeepwalker]

Probably the best to start, as stated above, would be to take it to a parts store and get a code-scan.

But overall, you might be money-ahead taking your truck to a competent shop. How many videos would you need to watch? There could be So many things...and several tests you probably don't have the tools to do. People on forums can shoot from the hip, and toss this and that...and 12 other possibilities what the problem might be, but the cause could be a couple issues. Or even three at the same time. The only way to know would be to do a thorough analysis and look-over.

So, rather than spend the next 9 months and 100 hours of video watching, and getting angry at the truck... maybe a few hundred bucks could solve the problem and prevent worse problems from festering (they only get more expensive). Your truck is telling you "I've got a problem." Get it fixed and move on to more pleasureable things in your life. Best of luck.

 

[Burla]

Apologies for the lack of details and I will go ahead and say that I have failed miserably regarding maintenance but really trying to get back on it.
I've had the truck for about 5 or 6 years now. Mileage is at 124,000. I've changed the air filter but it's been awhile. Haven't done the spark plugs (I know and I'm ready the **** I deserve lol). I've had to replace the bolts and have the manifold resurfaced 3 times now. O2 sensors replaced 2 years ago and no codes come up.
Complete honesty, I'm ignorant when it comes to working and maintenance on my truck besides oil changes. Any guidance as far stuff I need and should have done is greatly appreciated and I can always watch videos on how to do things.

most engines are still governed by 3 main things, fuel air and spark. Maintenance helps keep the engine burning efficiently. It is just like a fire in the fire place for air and fuel, wrong fuel or lack of air and the fire doesn't "burn" efficiently. Creates creosote and many problems in the pipes, not dissimilar with an engine. Maintenance should address fuel, air and spark and their pathways. Throttle body is a big spot along with egr. If you never have done plugs obviously you are overdue there. Replace air filter, run some redline si-1 clean injectors and combustion chamber, consider Valvoline restore and protect for a run. Google whatever dealer says should be a 60k mile service and consider those items. As far as mileage it comes down to fuel, air and spark and if that is burning efficiently.

 

[Joshua Peterson]

So, here it is. I've had the tires and rims for about 3 years now. I really appreciate the advice. I've taken my truck to several shops and they have not i.pressed me at all. Working on finding a new shop. Limited shops where I live, Eureka, CA but I'm sure there is one out there. I did just recently got the OBDLink MX+ and AlphaOBD app.
@Burla Thank you for your reply. I will definitely start looking into those things.
Kind of stupid learning this stuff later in life. Dad was a mechanic and service manager. I asked so many times to show .e how to change oil, or even go over the engine a d stuff with me in my first car. Easier for him to just take it to the shop and get it done. However, I have a 17yo son who had taken an interested in engines (especially diesel). We got him a 1984 F250 6.9IDI. Engine got seized and was shot. He found an engine locally, pulled it, pulled old one out, and put the other one in his truck (with a little help from me) by himself. So, learning little by little for myself.

 

[Joshua Peterson]

One last thing. Truck has a horrible, loud, squeking noise. Does it going in reverse and driving, mainly over any kind of bump. I know my ball joints are shot. I have replacements and will be installed next week. Can't figure out where it's coming from though. Almost sounds like from the back springs. Hell, I don't know. Wheel bearings?

 

[Dredger]

Kind of stupid learning this stuff later in life. Dad was a mechanic and service manager. I asked so many times to show .e how to change oil, or even go over the engine a d stuff with me in my first car. Easier for him to just take it to the shop and get it done.

Hmmm . . . My mom would say when I was young, "The shoe makers kids never had any shoes." You know, I never questioned it, but I also never understood that until I got older.
It's never too late to learn and its certainly not stupid learning anything when you get older. We would be wise to consider ourselves lifetime learners. I applaud you for digging in!
If you still have the owner's manual, go to the maintenance section and catch everything up to the listed years/milage of your vehicle. It's a beginning . . .

 

[markabby]

"winter blended fuel" brought to you by (insert favorite bogeyman here)

"it's not a flaw, it's a feature!"

i've noticed mine has gone down a little this winter. I thought it was the winter blend...whatever that is, but, it could also be warming the truck up before driving too.

 

[Curmudgeon]

@Joshua Peterson please note...

In post #16 you said; "I've had to replace the bolts and have the manifold resurfaced 3 times now." You are referring to the exhaust manifold, this is
a common issue that most of us have had, but...

In post #3 @Daw14 said; "Have you checked the torque of your intake manifold bolts , they should all be 108 inch pounds, 5/16” or 8mm is the size.

Very many of us have found the intake manifold bolts loose. The best way to check them is with a 1/4" drive ratchet, 1/4" extension, and 5/16 or 8mm socket. The extension can probably be no more than 6" long, but the skinny 1/4" is helpful in getting to those bolts.

EDITED to add: Here is a pic someone posted about the torque sequence for the intake manifold. Please NOTE that this drawing is for the 5.7L intake in a CAR so the air pipe is facing the driver's side. Just verify you are matching front to front.

 

[jws123]

winter blend im gettin 12mpg around town

 

[raggdoll]

Try a tank of 91 and report back. Winter gas = less mileage, we are the lucky ones who feel it more then others like people who drive priuses. Technical term winter gas has less energy in it, which is the science of the why.

And a can of Seafoam...