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i worked at Kenworth for years and have replaced countless DEF pumps, tanks, filters ect. I understand what its for how it works and all that junk. However i have never onwed a diesel and have never needed to use DEF personally. How long does it last? How big is the tank on the 2011 6.7s? I dont see a DEF gadge so how do i know when im low? Do you buy boxes of DEF or do u fill up at loves?
i worked at Kenworth for years and have replaced countless DEF pumps, tanks, filters ect. I understand what its for how it works and all that junk. However i have never onwed a diesel and have never needed to use DEF personally. How long does it last? How big is the tank on the 2011 6.7s? I dont see a DEF gadge so how do i know when im low? Do you buy boxes of DEF or do u fill up at loves?
any information would be appreciated thanks
Towing you can probably make it 500-750 miles. Unloaded probably twice that.. The tank should hold around 5 gallons. My nephew works at MHC Kenworth and gets trucks in fairly often that got bad DEF from the truck stops. So I get mine at Walmart. I use Supertech but if you like brand names buy the Peak
Your owner's manual will give you approx miles on the DEF. Towing, you should get around 2,000 miles to 4100 miles unless you have the 4.30 gears then it less. See the photo. This is from my 2015 owner's diesel supplemental manual.
Every trip towing to CO is about 1500 miles round trip. Usually when I get back I put a 2.5 gal jug in it. So my math was a little off. LOL Based on this and if it's a 5 gal tank about 3k miles if towing.
I have a 2013 with the same size of the DEF tank. I can run about 4 to 5 K before fill up
While you can fill up at a truck stop I never do since it is not that often.
I fill up using the ford filler spout since it seals, does not leak and prevents an overfill. Over filling in the Summer is ok, but in winter the def will freeze and expand.
Another tip: don't fill until you get the warning of <200 miles to empty. Then a complete fill up. Using this method keeps the system from being confused.
There are lots of folks that fill up much sooner but the completed empty and fill up method works best to keep it working good imho.
Last edited by senix; Jun 21, 2020 at 07:39 AM.
Reason: added info
I use the Wally World Super Tech brand for $7.88 for 2.5 gallons, if I remember correctly (the price).
I'm one of those guys who try to fill up every 3k to 4k miles to keep fluid on the heater as every Time the truck starts and the glow plugs light, so does the DEF tank heater. I can't remember but I thought a Ford tech on here recommended that. I have never had any problems.
I use the Wally World Super Tech brand for $7.88 for 2.5 gallons, if I remember correctly (the price).
I'm one of those guys who try to fill up every 3k to 4k miles to keep fluid on the heater as every Time the truck starts and the glow plugs light, so does the DEF tank heater. I can't remember but I thought a Ford tech on here recommended that. I have never had any problems.
I suppose u cant speak for fords but on the big rigs at KW this was definitely the case. So much infact that the DEF level sensor/heater was on back ordered for constant failure due to the heater being exposed when DEF was low.
I have a 2013 with the same size of the DEF tank. I can run about 4 to 5 K before fill up
While you can fill up at a truck stop I never do since it is not that often.
I fill up using the ford filler spout since it seals, does not leak and prevents an overfill. Over filling in the Summer is ok, but in winter the def will freeze and expand.
Another tip: don't fill until you get the warning of <200 miles to empty. Then a complete fill up. Using this method keeps the system from being confused.
There are lots of folks that fill up much sooner but the completed empty and fill up method works best to keep it working good imho.
dam conflicting advice lol. All grate information though i appreciate it. Didjt think about freezing. Currently live in AZ but i do make trips to colder climates and plan to move back to WA soon so i will take that into consideration
Your owner's manual will give you approx miles on the DEF. Towing, you should get around 2,000 miles to 4100 miles unless you have the 4.30 gears then it less. See the photo. This is from my 2015 owner's diesel supplemental manual.
thank you i appreciate the information. My truck unfortunately didnt come with the owners manual honestly much further distance than i expected
I suppose u cant speak for fords but on the big rigs at KW this was definitely the case. So much infact that the DEF level sensor/heater was on back ordered for constant failure due to the heater being exposed when DEF was low.
You're correct that I can't speak for all the 6.7 Fords but enough people post on here that they have their DEF in-tank heater go out. I have let the truck go to the 500 miles warning but once I started thinking about and saw that from a Ford factory tech, @m-chan68 I wanted to prolong my heater's life if possible. I tagged him here so hopefully he will respond. I have never had any DEF fill level sensor problems by keeping the tank topped off. Maybe I'm not correct about the DEF heater coming on in the warmer weather, but I thought I read that when the glow plugs light off, the DEF heater comes on because it's on the same circuit. m-chan68 can correct me.
I keep notes on my cell phone. Here's the one:
Last edited by Overkill2; Jun 24, 2020 at 09:12 AM.
Reason: add to post
You're correct that I can't speak for all the 6.7 Fords but enough people post on here that they have their DEF in-tank heater go out. I have let the truck go to the 500 miles warning but once I started thinking about and saw that from a Ford factory tech, @m-chan68 I wanted to prolong my heater's life if possible. I tagged him here so hopefully he will respond. I have never had any DEF fill level sensor problems by keeping the tank topped off. Maybe I'm not correct about the DEF heater coming on in the warmer weather, but I thought I read that when the glow plugs light off, the DEF heater comes on because it's on the same circuit. m-chan68 can correct me.
I keep notes on my cell phone. Here's the one:
I believe you are correct about the def heater coming on during the glow plug cycle. It does a self test during every key cycle if I recall correctly, just to check that the current draw to all the def heaters are within spec.
When my def tank heater failed, I'd get the fault code, and no matter how many times I cleared it, It'd keep coming back after a key cycle, even in warmer weather. This seems to me to imply that the self test occurred even in outside temps above freezing atleast.
My Def tank heater failure was due to me filling the tank full in the winter, by the way. I filled at the pump until the pump shutoff, then drove 100 miles and parked the truck for the night. Theory is that the def froze in the full tank and expanded enough to damage the heater. I now intend to never fully fill the def tank in the winter months when it'll get below 12 F.
I believe you are correct about the def heater coming on during the glow plug cycle. It does a self test during every key cycle if I recall correctly, just to check that the current draw to all the def heaters are within spec.
When my def tank heater failed, I'd get the fault code, and no matter how many times I cleared it, It'd keep coming back after a key cycle, even in warmer weather. This seems to me to imply that the self test occurred even in outside temps above freezing atleast.
My Def tank heater failure was due to me filling the tank full in the winter, by the way. I filled at the pump until the pump shutoff, then drove 100 miles and parked the truck for the night. Theory is that the def froze in the full tank and expanded enough to damage the heater. I now intend to never fully fill the def tank in the winter months when it'll get below 12 F.
I fill up with the factory fill nozzle that prevents over filling so it doesn't freeze and crack the neck in cold weather. I even use it in the summer.
I fill up with the factory fill nozzle that prevents over filling so it doesn't freeze and crack the neck in cold weather. I even use it in the summer.
The factory fill nozzle prevents overfilling spills, not overfilling in regards to freezing. It'll still fill the def tank up into the filler neck, which is too full in freezing weather. I use this nozzle too and its nice to prevent spillage that can damage paint, but in the winter, I have to make sure to stop before the factory fill nozzle stops.
