F250 Superduty 6Ldiesel bad gas mileage

flowerpower · #1 (**permalink**) 10-28-2009, 12:47 PM

Hello all, I am not only a newbie here but also a woman who could use a hand with a very detailed and easy explanation of things..so please bear with me as I try to get my truck to work better for me.

My truck is a 2004 which I bought brand new. Love it. I want to maintain it as best I can but not go overboard. Here is my current problem. I am getting VERY VERY bad gas mileage! When I look at the overhead computer it tell me the instant gas mileage. At this time as I sit at idle not even moving, the computer says 7 MPG! As I start to move very slowly it drops to like 4 MPG then levels off at about 8 or 9 MGP. That is horrible! IF I get on the highway and start going about 70 mph it levels off at 10-12 mpg. Even going down a hill I am not seeing the computer tell an impressive number for MPG! So -here is what I think it might be... about 3 months ago I had my EX put a new air filter on after he changed the oil, oil filter, and 1 fuel filter. He had ALOT of trouble getting this air filter to go into place...do you think he may have cracked it? or maybe it is not sitting properly inplace? Could this cause a problem bringing air into the engine? My truck does spit and sputter at times.. randomly ... but I have never been able to decipher that issue for 3 years... now all of a sudden after the last maintanence the gas mileage is really horrible. Please some advise is needed! Where do I start?

Kim

Robs06SuperDuty · #2 (**permalink**) 10-28-2009, 01:37 PM

clogged EGR? what type of air filter did he put on it? OEM Replacement?

tazo · #3 (**permalink**) 10-28-2009, 01:37 PM

Kim,
There could be a few things going on. When your ex changed the fuel filter did he change both of them? There is one on the frame rail and another on the engine and they should be changed in pairs. Also the fuel filters need to be motorcraft or racor fuel filters. The other aftermarket one do not work correctly. The same goes with the oil filter. When he changed the air filter did he use the oem one with the blue media? Maybe he didn't get the filter in correctly. It is a bit tricky. There is also a sensor there maybe it got damaged. When you check the fuel mileage do you just go by the lie o meter or do you calculate by hand. I do both and calculating by miles driven by fuel consumed is more accurate. Just some food for thought.

flowerpower · #4 (**permalink**) 10-28-2009, 03:01 PM

Thank You for the two replies so quickly. Clogged EGR (ERG??whatever) how can I tell if that is the problem?

I bought the motorcraft fuel filter off ebay and it was brand new and still inthe box. It was sold by a dealership going out of business earlier this year before cash for clunkers rolled around. However, I only had the 1 filter, and I am not sure what location he installed it at....as for the air filter - he had a real hard time getting it to click into place all the way around and I am not sure who manufactured the filter but I do not remember it being blue in color...the outside was black plastic and it had a white fillament inside if I remember correctly. Could that really make a difference? The make of the parts? come on.

The senser getting damaged. What type of sensor is in the air filter area? How would I know if it is damamged?

So, if I know what I am asking for at the Ford dealership service dept, then I might be able to diagnose this problem without giving them my first born! Certainly costs to diagnose play into the situation. also finding a mechanic outside the dealership for a diesel seems to be a problem. How do most people find diesel mechanics?

Kim

tazo · #5 (**permalink**) 10-28-2009, 03:47 PM

http://www.ford-trucks.com/forums/30...ch-folder.html
Kim, This is the tech folder on the 2003-2007 diesel page. Lots of good info.
Finding a good diesel mechanic is hard to come by. If you find a good dealer they usually have good diesel techs.
The sensor near the air filter is the mass air flow sensor. But if something is malfunctioning there should be codes stored on the vehicles computer. And if it is bad enough you should have a check engine light on. Good luck

papadelogan · #6 (**permalink**) 10-28-2009, 04:22 PM

Quote:

Originally Posted by flowerpower

Thank You for the two replies so quickly. Clogged EGR (ERG??whatever) how can I tell if that is the problem?

I bought the motorcraft fuel filter off ebay and it was brand new and still inthe box. It was sold by a dealership going out of business earlier this year before cash for clunkers rolled around. However, I only had the 1 filter, and I am not sure what location he installed it at....as for the air filter - he had a real hard time getting it to click into place all the way around and I am not sure who manufactured the filter but I do not remember it being blue in color...the outside was black plastic and it had a white fillament inside if I remember correctly. Could that really make a difference? The make of the parts? come on.

The senser getting damaged. What type of sensor is in the air filter area? How would I know if it is damamged?

So, if I know what I am asking for at the Ford dealership service dept, then I might be able to diagnose this problem without giving them my first born! Certainly costs to diagnose play into the situation. also finding a mechanic outside the dealership for a diesel seems to be a problem. How do most people find diesel mechanics?

Kim

hiya Kim!

I've got a 7.3 diesel myself, but one thing I've found is how helpful people are on this site. That being said, since you're basically having engine trouble, there is a forum just for the 6.0 diesels; it can be found HERE.

I'm certain that posting your problem in there will get you more specific and thorough help. (I've actually notified the moderator of this forum and asked them to move this thread there for you, so you don't have to start over or check 2 threads.)

Also, I'm sure you're not the first to have such problems as sputtering or asking about filters. The search feature can pull up tons of great info from people that were once in your shoes. It's in the same place at the top of each forum screen, but I've circled it in red in the pic below for you.

Does the brand of filter matter? In a word.... YES. Seriously. The quality of the filter, how well it filters, and with the least restriction matter, ESPECIALLY in a diesel. For example, the 6.8 V10 gas engine takes 6 quarts of oil for a change. My 7.3 and your 6.0 take 15!!! Quality filtration is critical.

I'm about tapped for techie on the 6.0 but use that 6.0 forum, search around a little, and don't be afraid to ask for some help. I'm sure you'll find some great people in there that might just be not that far from you.

Krewat · #7 (**permalink**) 10-28-2009, 04:48 PM

Moved to the 6.0L forum. And WELCOME to FTE!

SHAWN056.0 · #8 (**permalink**) 10-28-2009, 05:05 PM

Welcome to FTE! The above posts are right. These trucks take a little more pampering than your average vehicle. Always use motorcraft, racor filters aftermarket ones especially the oil filter do not fit properly. They don't seat all the way down allowing the oil to not be filtered and also ford knows this and they'll deny some warranty claims if these aftermarket filters are used. Maintaince maintaince maintaince not to try to scare you but checking and keeping up on services on these trucks is key to a longer lasting happy engine. Synethic oil seems to make em happy too 5w40. As for the lie o meter I always hand calculate mine as that thing gets screwy every time I drive it.

Read up all you can in the tech folder at the top of this forum and if ya have any questions don't hesistate to ask there are alot great techs on here.

Thanks

Shawn

cmcowboy · #9 (**permalink**) 10-28-2009, 05:31 PM

Quote:

Originally Posted by flowerpower

My truck is a 2004 which I bought brand new. Love it. I want to maintain it as best I can but not go overboard. Here is my current problem. I am getting VERY VERY bad gas mileage! When I look at the overhead computer it tell me the instant gas mileage.

Welcome to FTE!!!!!
Also I would like to add, My 2006 just tells me an average MPG, I'm pretty sure your does to, it is not an instant reading. I also agree with above posters, hand calculate, I always get different readings then the truck tells me.

Like others have said as well maintenance, maintenance and then more maintenance. Using good quality filters and fluids changed regularly on time. A good fuel additive as well, and good fuel from a station that sells allot of fuel.
Welcome again and good luck