Ford knox sensor

[ACZL]

Have other folks had issues w/ Fords Knox sensors? If so, did your dealer tell you why it failed or triggered a engine light? Mine is telling me it's being tripped by using aftermarket fuel additives which I find hard to believe. If that's the case, what are we supposed to do to prevent gelling in winter months?

[Grit_dog]

1. Any dealer who can’t spell the broken part name, be suspect of.
2. They don’t know what you put in the fuel tank. So if you told them, shut up and don’t tell them
3. High doses of additives could affect sensor readings. But I’m no expert. Does it go away if you stop putting the snake oil in?
4. You don’t need anti gel except in specific situations where you live.
A. If you got a tank of fuel from down south and somehow make it back to cold weather.
B. If you’re traveling somewhere where this same condition is possible in the winter. (It is possible)
C. If it gets significantly colder than the expected low temps for that time of year. (-20 in October. -40 in Jan type of thing)

[ShinerBock]

FishOnOne wrote:

ShinerBock wrote:

DownTheAvenue wrote:

ACZL wrote:

DownTheAvenue wrote:
Stop using the aftermarket fuel additives. You are told why your check engine light comes on. Diesel fuel already is formulated to prevent gelling right out of the pump. Isn't science amazing?

Try telling that to folks in areas where temps get down to -30 to -20.

My son drives an over the road tractor trailer Chicago and north into Minnesota and Wisconsin and has yest to put anything in the truck but the fuel that comes out of the pump. The refiners put in anti gel additives as it leaves the terminal. You can buy all the snake oil you want and put it into your truck to set off the check engine light and ultimately lead to a shorter life of those sensors. Its your truck and your wallet. Your dealer told you to stop.

Many long hisl truck drivers that go from south to north in one tank need them because the fuel in the south doesn't have these additives.

Also, aside from California and Texas that have higher fuel requirements than the US federal standards, most states only meet the minimum federal diesel fuel standards of 40 octane and lower scar value. Not saying everyone needs it, but there are those that might.

40 cetane...

Also I remember a couple years ago reading another diesel forum there was a serious rash of diesel fuel gelling up north. I didn't read of many issues this past winter.

Yeah, Texas fuel has a CN 48 minimum,California has a CN of 53 minimum, and all other states go by the federal standard which a CN 40 minimum. Most diesels operate at peak efficiency at CN levels between 48-50, especially diesels that rev high like most light duty diesels engines do. EU has a CN minimum of 51.

[ShinerBock]

Flashman wrote:
Is this another Ford thing?

No, it is any diesel with NOx sensors which is all of them.

[FishOnOne]

ShinerBock wrote:

DownTheAvenue wrote:

ACZL wrote:

DownTheAvenue wrote:
Stop using the aftermarket fuel additives. You are told why your check engine light comes on. Diesel fuel already is formulated to prevent gelling right out of the pump. Isn't science amazing?

Try telling that to folks in areas where temps get down to -30 to -20.

My son drives an over the road tractor trailer Chicago and north into Minnesota and Wisconsin and has yest to put anything in the truck but the fuel that comes out of the pump. The refiners put in anti gel additives as it leaves the terminal. You can buy all the snake oil you want and put it into your truck to set off the check engine light and ultimately lead to a shorter life of those sensors. Its your truck and your wallet. Your dealer told you to stop.

Many long hisl truck drivers that go from south to north in one tank need them because the fuel in the south doesn't have these additives.

Also, aside from California and Texas that have higher fuel requirements than the US federal standards, most states only meet the minimum federal diesel fuel standards of 40 octane and lower scar value. Not saying everyone needs it, but there are those that might.

40 cetane...

Also I remember a couple years ago reading another diesel forum there was a serious rash of diesel fuel gelling up north. I didn't read of many issues this past winter.

[Flashman]

Is this another Ford thing?

[RAS43]

I worked for a trucking company in Denver that ran to California daily. In the winter we had no issues from Denver West with our treated fuel. However, on return trips we had fuel issues coming over the mountains. Fuel jelled in tractors and refrigeration units. Drivers were instructed to add an additive east bound due to the California or Nevada fuel which was blended for the local temperatures. Some call it snake oil, we called additives a necessity.

[ShinerBock]

DownTheAvenue wrote:

ACZL wrote:

DownTheAvenue wrote:
Stop using the aftermarket fuel additives. You are told why your check engine light comes on. Diesel fuel already is formulated to prevent gelling right out of the pump. Isn't science amazing?

Try telling that to folks in areas where temps get down to -30 to -20.

My son drives an over the road tractor trailer Chicago and north into Minnesota and Wisconsin and has yest to put anything in the truck but the fuel that comes out of the pump. The refiners put in anti gel additives as it leaves the terminal. You can buy all the snake oil you want and put it into your truck to set off the check engine light and ultimately lead to a shorter life of those sensors. Its your truck and your wallet. Your dealer told you to stop.

Many long hisl truck drivers that go from south to north in one tank need them because the fuel in the south doesn't have these additives.

Also, aside from California and Texas that have higher fuel requirements than the US federal standards, most states only meet the minimum federal diesel fuel standards of 40 octane and lower scar value. Not saying everyone needs it, but there are those that might.

[DownTheAvenue]

ACZL wrote:

DownTheAvenue wrote:
Stop using the aftermarket fuel additives. You are told why your check engine light comes on. Diesel fuel already is formulated to prevent gelling right out of the pump. Isn't science amazing?

Try telling that to folks in areas where temps get down to -30 to -20.

My son drives an over the road tractor trailer Chicago and north into Minnesota and Wisconsin and has yest to put anything in the truck but the fuel that comes out of the pump. The refiners put in anti gel additives as it leaves the terminal. You can buy all the snake oil you want and put it into your truck to set off the check engine light and ultimately lead to a shorter life of those sensors. Its your truck and your wallet. Your dealer told you to stop.

[Lynnmor]

Maybe the dealer wants to charge you an amount that will require robbing Fort Knox. :B

[Turtle_n_Peeps]

mleekamp wrote:
....and by the way, it's a Knock Sensor, not Knox

No such thing in a diesel.

There is a NOx sensor and yes, additives can cause problems as Shiner has already said.

[FishOnOne]

It was most likely a Nox sensor. Mine failed at around 110k miles and I don’t run additives.

[ShinerBock]

ACZL, if it is a NOx sensor that your are referring to then yes aftermarket fuel additives could be the culprit. NOx is created when in cylinder temps get above 2,800F which a diesel engine normally does. To combat this, two things may happen. One, the EGR valve will open introducing cooled exhaust gas back into the intake to cool the in cylinder temps down. Two, if the SCR catalyst is hot enough, the system will inject more DEF if the NOx sensors detect more NOx downstream from the DPF.

You have NOx sensors at various parts in the exhaust/emissions system, and a fuel additive may alter NOx level. So basically what is happening is the ECM is triggering the EGR and SCR to combat the NOx being created, but the fuel additive may be making the engine run more efficient creating more NOx(yeah, an oxymoron). This will trigger a CEL because the engine is doing what it is programmed to in order to reduce NOx, but the amount is still not coming down to normal levels due to the fuel additive.

NOx and emissions devices is the real reason why diesel makes don't recommend additives anymore even though they want the best fuel possible ran through their engine and they do make them run more efficiently. If they recommend a fuel additive that increased NOx output or damages emissions equipment, then they could be liable.

[ShinerBock]

The are knock sensors and a NOx sensors. Which one are you referring too? I am guessing since it is a diesel in your sig that you are referring to the NOx sensor.

[ACZL]

DownTheAvenue wrote:
Stop using the aftermarket fuel additives. You are told why your check engine light comes on. Diesel fuel already is formulated to prevent gelling right out of the pump. Isn't science amazing?

Try telling that to folks in areas where temps get down to -30 to -20.