2012 5.7 loss of power and bad mileage

[boogie067]

I have a 2012 ram 5.7 4x4 5 day ago notice loss of engine power and horrible gas mileage. Engine light is not on. Idles fine no misfires. Shifts fine. Is only getting 9.5 mpg. Truck has 79,000
Any ideas?i have already checked all brake calipers to make they are working properly.

 

[daveray9]

Plugs are copper... change every 30k recommended. Realistically 50 does it. How old are yours?

Sent from my SM-G960U using Tapatalk

 

[boogie067]

Bought the truck with 55,000. I have not changed them since I bought it.

 

[Fast69Mopar]

I have a 2012 ram 5.7 4x4 5 day ago notice loss of engine power and horrible gas mileage. Engine light is not on. Idles fine no misfires. Shifts fine. Is only getting 9.5 mpg. Truck has 79,000
Any ideas?i have already checked all brake calipers to make they are working properly.

How are you calculating the fuel economy? Are you going by what the fuel mileage shows in the EVIC or are you putting pen to paper and doing the math every time you fuel up?

Before the truck started to show it was getting poor fuel economy in the last 5 days, what was the fuel economy before this issue arose? Have you changed where you purchase fuel from?

 

[boogie067]

I have been checking mileage with the truck computer and pen and paper at every fill up. I have usd different gas station. I have been getting 16 to 18 miles per gallon prior to issue.

 

[Loudram]

Bought the truck with 55,000. I have not changed them since I bought it.

Did the previous owner change them? Maybe time for a tune up. New plugs and clean or replace the various sensors. Do the easy and cheap fixes first.

 

[16Ram4x4]

Besides changing the spark plugs, check the plug wires for any possible damage or arcing.
Also has the tone of the exhaust changed over those five days? Worst case scenario is you have a bed catalytic converter that's plugging up or has broken up inside causing your issues.
I had a 89 Dodge Dakota with the 3.9L V6 and it only got 5 to 9 mpg when I first bought it at 73k. The catalytic converter had broken down inside and rattled when you shoved the exhaust system around. After a new catalytic converter installed my fuel economy went up to 14 to 16 mog

 

[daveray9]

So, right after I got my JBA shorties installed my MPG went from 19 to about 13 Highway.. I also added a premium tune and leveled the truck out. Didn't expect that big of a drop but... I changed the plugs and that got another bump. I have checked and there are no leaks. My next stop was 02 sensors but I've been lazy.

Curious what is up with yours, especially if nothing has changed.

 

[boogie067]

So, right after I got my JBA shorties installed my MPG went from 19 to about 13 Highway.. I also added a premium tune and leveled the truck out. Didn't expect that big of a drop but... I changed the plugs and that got another bump. I have checked and there are no leaks. My next stop was 02 sensors but I've been lazy.

Curious what is up with yours, especially if nothing has changed.

Have not changed a single thing. will keep posted.

 

[Fast69Mopar]

I have been checking mileage with the truck computer and pen and paper at every fill up. I have usd different gas station. I have been getting 16 to 18 miles per gallon prior to issue.

Okay. Good. The only real way to calculate fuel mileage is by putting pen to paper and using the miles and gallons used. So, now we could really use a scan tool to take a look at a few things. When fuel mileage gets bad the first thing I look at is the Short Term Fuel Trim and the Long Term Fuel Trim.

These two items tell us what is going on with the fuel. The Short Term Fuel Trim tells us what is happening with the fuel right now. The Long Term Fuel Trim tells us what has been happening in the recent past. If the motor is using more fuel than usual to get the job done then the Short Term Fuel Trim will be adding fuel and show a positive number. The Long Term Fuel Trim will be subtracting fuel.

Do you have access to a scan tool or a mechanic friend you can borrow one from?

 

[boogie067]

Okay. Good. The only real way to calculate fuel mileage is by putting pen to paper and using the miles and gallons used. So, now we could really use a scan tool to take a look at a few things. When fuel mileage gets bad the first thing I look at is the Short Term Fuel Trim and the Long Term Fuel Trim.

These two items tell us what is going on with the fuel. The Short Term Fuel Trim tells us what is happening with the fuel right now. The Long Term Fuel Trim tells us what has been happening in the recent past. If the motor is using more fuel than usual to get the job done then the Short Term Fuel Trim will be adding fuel and show a positive number. The Long Term Fuel Trim will be subtracting fuel.

Do you have access to a scan tool or a mechanic friend you can borrow one from?

I do not.

 

[boogie067]

Okay. Good. The only real way to calculate fuel mileage is by putting pen to paper and using the miles and gallons used. So, now we could really use a scan tool to take a look at a few things. When fuel mileage gets bad the first thing I look at is the Short Term Fuel Trim and the Long Term Fuel Trim.

These two items tell us what is going on with the fuel. The Short Term Fuel Trim tells us what is happening with the fuel right now. The Long Term Fuel Trim tells us what has been happening in the recent past. If the motor is using more fuel than usual to get the job done then the Short Term Fuel Trim will be adding fuel and show a positive number. The Long Term Fuel Trim will be subtracting fuel.

Do you have access to a scan tool or a mechanic friend you can borrow one from?

 

[indept]

Check the air filter. Unless it looks brand new, change it just to be safe.

 

[boogie067]

tried that.

 

[boogie067]

If it’s a faulty injector, would the engine light come on?
Now it is starting a little harder and making a miss fire when starting.

 

[boogie067]

It’s at the dealer. I will update when it’s fixed.

 

[Loudram]

Your symptoms sound just like mine on the '14 Express I just traded in. I never did figure out what was wrong with it. I was thinking the start of a lifter failure. That's why I traded it in. I'm looking forward to hearing what the issue is. Please keep us updated.

 

[RamCares]

It’s at the dealer. I will update when it’s fixed.

Hey boogie067, if you are in need of any additional support while in service, please do not hesitate to send us a PM.

Mark
RamCares

 

[boogie067]

Your symptoms sound just like mine on the '14 Express I just traded in. I never did figure out what was wrong with it. I was thinking the start of a lifter failure. That's why I traded it in. I'm looking forward to hearing what the issue is. Please keep us updated.

You did the right thing trading it in!!!!!

Still at the dealer. Dealer said lifter bad “know issue for this motor “ ended up ruining the cam. Stay tuned this is going to be expensive.

 

[Loudram]

Sorry to hear that. I was hoping it was just a bad sensor. Thanks for the update.