Dale_S
Saugus, CA
Senior Member
Joined: 05/23/2007
View Profile
 Offline
|
Things I would check, standing in the front of the truck look towards the back of the engine, towards the firewall, you should see a blue hose just to the left of the turbo, make sure it has not worked itself loose. I have a seen a few do that, and you loose a little boost, just enough where you are not getting the right boost, but not enough where it triggers any sensors, or you really notice a huge lose of power. If it is loose, remove it, clean it up real well, grab some hairspray (I use AquaNet Super Extra Hold), spray the ends before you put it back on there.
the next thing I would check is the bleeder screw on top of the fuel filter. See if there is any diesel residue around it. They are cheap nylon, and I would change it out with an aftermarket stainless steel screw that are available from a few vendors.
If you are letting the folks who change your oil, change your fuel filter, I would also check the WIF sensor in the bottom. If it is overtightened it can get hairline cracks in it. Also, never let them use a wrench to tighten the fuel filter, they will eventually crack the filter housing and it will leak.
|
maxum1989
Vancouver Canada
Senior Member
Joined: 03/29/2006
View Profile
|
I just filled up the tank today. My last tank I got 10.7 mpg. Seems quite low to me.
2008 Chevy 2500hd Diesel
2006 Wildcat 27 bhwb
|
45Ricochet
North Idaho
Senior Member
Joined: 09/04/2009
View Profile
|
maxum1989 wrote:I just filled up the tank today. My last tank I got 10.7 mpg. Seems quite low to me.
10.7 is about right for towing 
Joking aside is that a hand calculation? Can't wait to hear your next MPG report cause 10.7 tells me something ain't right.
06 Dodge 3500 CC LB Laramie 4x4 Dually 5.9 Cummins 325/610 48RE Jacobs brake Smarty Jr 
GVWR 12,200 Payload 4580
06 Grand Junction 34' High profile 15500 GVWR 3200 pin Mor/ryde 5500 Onan genny Dual A/C
27' Hallett 502, 500HP
|
maxum1989
Vancouver Canada
Senior Member
Joined: 03/29/2006
View Profile
|
Yes, hand calculation for mgg's. I went 275km (170 miles) and put in just shy of 60 liters (15.85 gallons). 170/15.85=10.72 mpg. Another way to put that is crappy mileage. I agree that it would be fine if I was towing my fifth wheel (10000 pounds) in that time, but no towing at all, just probably 65 to 75% around town and the rest highway.
I am going to try and make a list of everyone's suggestions and go out to the truck and do my best to figure it out. I certainly don't want to pay dealership rates to search this out. That will be my last resort. I will even do another oil change at a different location prior to taking it to the dealership to see if that helps. Please keep the suggestions coming and I will do my best to sort this out. I will be sure to post whatever it takes to fix this so others can watch out for this as well.
Thanks.
|
mudmaker
Iowa
Senior Member
Joined: 10/15/2006
View Profile
Good Sam RV Club Member
Offline
|
Air filters aren't expensive and they can seal over making air pass thru a lot harder and decreasing mileage.
Glen and Loretta
Marc, Jake, and Kirsten
Coachmen Chaparral 276RLS
08 Saturn Vue
04 GMC 2500HD Sierra CC 4x4
03 Dodge 3500 DRW quad 5.9HO
Yamaha EF2400is gen
2 official rallys!
|
|
|
'68Monaco440HP
Corpus Christi, Texas
Senior Member
Joined: 11/14/2003
View Profile
Offline
|
Attend to the basics:
Fuel filter
Air filter
Alignment
Tire pressure
Brake drag
CAC leaks
Short trips in cold weather (less than 30-miles) keeps ALL fluids/greases from reaching operating temperatures. On top of that (the second consideration) is that "winter fuel" has lower energy content.
A winter front and the use of the block heater will get coolant temps up faster, and maintain them more easily; actual outside temperature is irrelevant. Combine all trips (eliminate short trips) into a long loop back to the house. Use less fuel when driving, and save fuel by not driving (all in a manner of speaking). Do the same work, but with less fuel. Fewer trips, but with more stops per trip; as necessary.
Attention to details can bring even a proper running diesel pickup to higher mpg figures. I brought my in-town annual average mpg from 18 to 21-mpg on my 3/4T CTD over a few years. The past 1,100-miles in town have been at 23-mpg. (Highway is a bit higher).
Problems outside of basics show up more easily if accurate records are kept. Noting how many miles until empty is NOT accurate record keeping as one needs to be able to chart changes as low as 10% (and then explain them satisfactorily).
.
[Sold] 1983 [34'] Model 3411 Silver Streak
1976 32' Continental Supreme Silver Streak at present
2004 DODGE 305/555 ISB, QC SRW LB NV-5600, 7,400-lbs & Hensley Arrow
Combination is above 15,000-lbs. 15-cpm solo, 25-cpm towing
|
NewsW
US
Senior Member
Joined: 02/06/2012
View Profile
|
Assuming you are not towing.
Based on your symptoms.
Bet you have a stuck thermostat and what is happening is your vehicle never comes up to warm --- and an over rich fuel mixture is being injected to compensate for the cold and trying to heat up the engine.
If you closed off most of the rad, and it made a difference, that is it.
Posts are for entertainment purposes and may not be constituted as scientific, technical, engineering, or practical advice. Information is believed to be true but its accuracy and completeness cannot be guaranteed / or deemed fit for any purpose.
|
maxum1989
Vancouver Canada
Senior Member
Joined: 03/29/2006
View Profile
|
To add to the equation. I just got back from a trip up to Whistler and found that at highway speeds for a decent duration (1.5 hours) I can get just shy of 20 mpg as displayed on the trucks digital display. Yes this a mountain highway so there are some hills but nothing too bad. At highways speeds is this an acceptable mpg? I didn't think this was too bad. So, it seems most of my problem is city driving when the truck doesn't get to run for long periods of time. Maybe the latest suggestion of a thermostat problem is the case then? Would a thermostat problem go away when the truck is run for longer periods of time or is 19.5 mpg still too low for highway driving?
Also, my engine temp gauge has never shown to be anything but normal.
|
NewsW
US
Senior Member
Joined: 02/06/2012
View Profile
|
19.5 mpg is phenomenal for highway driving at 70+mph.
Lose a bit of mileage with altitude.
In town driving you are getting hammered by having to warm the motor...
Use a shield to block off rad to reduce excess cooling.
Thermostat could be partially stuck, but I am going to say it is probably normal.
Diesels don't do good with very cold starts and short runs.
|
45Ricochet
North Idaho
Senior Member
Joined: 09/04/2009
View Profile
|
maxum1989 wrote:To add to the equation. I just got back from a trip up to Whistler and found that at highway speeds for a decent duration (1.5 hours) I can get just shy of 20 mpg as displayed on the trucks digital display. Yes this a mountain highway so there are some hills but nothing too bad. At highways speeds is this an acceptable mpg? I didn't think this was too bad. So, it seems most of my problem is city driving when the truck doesn't get to run for long periods of time. Maybe the latest suggestion of a thermostat problem is the case then? Would a thermostat problem go away when the truck is run for longer periods of time or is 19.5 mpg still too low for highway driving?
Also, my engine temp gauge has never shown to be anything but normal.
LOL your truck is fine, case closed
|
|
|
