When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I went to scrape some snow off the drive that had been packed from driving on it for a few days - the sun was melting some of it off while I was out so I figured it would be a good time to try and loosen it up.
Thats when I noticed there was diesel fuel in it so got to looking at things and thinking about it. The puddle is under the passenger side, about under between the bed and cab joint. The only thing on that side of the truck that fuel goes to is the DPF.
176k miles and counting - original DPF. I have noticed fairly frequent regens for quite some time. With the fuel showing up that doesn't seem like a good mix.
Any educated thoughts on how much risk there is with this? IE - fire waiting to happen on the next regen or can I get through the winter and replace it when it warms up?
I am not sure how long the fuel collected in the spot, but the truck has been in that spot off and on since the 19th on top of the snow. I didn't crawl under it to check and didn't look at the snow that close until I tried to shovel it today. I will check things tomorrow and see if theres any fresh fuel drips.
Personally, I highly doubt the fuel is coming from the DPF. Is the leak on the driver side or the passenger side?
I would check the frame fuel module (Diesel Fuel Conditioning Module - DFCM) that contains the fuel filter. Who changed it last? Did they put clean oil on the o-ring before installing the cup? Did they check the yellow drain plug to insure the o-ring is installed on the plug? Did they put clean oil on the o-ring prior to installing the yellow plug? Was the cup screwed on until the stops met on the DFCM and the cup, both have stops and they should touch when tightened properly?
The leak is on the PASSENGER side - not the drivers side.
DFCM is on the drivers side.
As to the DFCM changes - I usually do those and have never had one leak. I did get the housing on wrong once and it threw codes, but re-lubing the seal and re-seating the housing took care of that one. Thats been probably 5-6 years ago now. The HPFP was recently replaced (had the decontamination kit installed - everything on the high pressure end). I do not know if they changed the fuel filters then off the top of my head. The fuel filters feed the high pressure system = are up stream of the high pressure pump, so I don't think they did. I keep on a 15k mile interval on the fuel filters. Oil changes every 5k.
In any event, I'll take a look at it later today and see if there's any fresh dripping. The truck ran a few miles yesterday - enough to warm up, but did not regen. I did not notice anything weird with how it ran and did not see any fresh leaks when I inspected DPF unit real quick after finding the fuel puddle.
I am not aware of any fuel lines on the passenger side. Probably not an ideal time nor weather to crawl under the truck, but have you check to see if fuel might be leaking from some area on the engine and running down the passenger side. Maybe an injector tube from the rail to the injector loose?
I would think the DPF remains hot enough to burn off any fuel fuel from the engine via the exhaust system.
If the truck was doing an active regen and you shut off the engine in the middle of it, there could be unburned fuel in the exhaust. It's going to find a way out. Maybe there is a leak in your DPF or somewhere else within the exhaust?
I checked it yesterday before I rolled and there wasn't any sign of fresh fuel. I did take pictures of the DPF and did not see any fuel drips/wet areads coming out anywhere. I'll look at it again today, different location and different parked angle (flat, not on a hill like usual).
This still remains a mystery. I haven't seen any fuel drips since. Sounds like that pesky problem that you keep trying to get diagnosed at the dealer and the dealer can't replicate so they have no clue...
Since I noticed the puddle of fuel I am tuned in to it so I'll keep an eye on it going forward and if anything pops up of note I'll chime back in.
Is it diesel fuel for sure that was in the snow? It could possibly be the new yellow coolant if you had it switched over. If you still have the orange coolant in both systems then nevermind me.
Good question - I did have them put an EGR core in when it was in for the HPFP/decontamination kit install, they had the housing out to get to the injectors so for them to move the housing they had to drain at least some coolant. Not sure if they dropped it all, flushed, and refilled. I will open it up and check.
Though, the puddle was quite a ways up-hill from the front of the truck so I am not sure how coolant would have flowed up there.
