Uneducated diesel newbie here....can someone please explain what oil stiction is? I've seen it talked about in several threads while I was researching a White smoke on cold start issue, but I have never seen Oil stictions clear definition. Thanks

 

The small spool valve in the top of the injector that controls the flow of high oil pressure fed to the intensifier piston in the fuel injector only moves .017", back and forth, on and off every time the injector fires. Many factors play in to how well that valve works such as, oil temp, oil quality, normal wear, ambient temp, and many others. As this valve ages it polishes itself inside the bore of the spool valve and as the spool valve slams back and forth it can set up the condition like a suction cup, hanging the valve to one side or the other. This uncommanded uncontrollable condition is called stiction or also called oil latching. Mostly its a rough run cold condition but in severe cases it can be a no start or pretty harsh misfire condition. Not only will running oil with too thick of a viscosity cause rough starts, but this also will interrupt the shuttle action of the spool causing injection timing to be retarded causing poor performance and decreased mileage until the oil is up to full operating temperature. It can also cause poor combustion and coking in the EGR components and the turbo.

Oil that stays inside the spool valve on a hot engine shutdown and is allowed to cool slowly in the injector can aggravate the condition on restart, so the newest reflash (calibration update to your truck's computer(s) uses inductive heat (remember your FICM is a DC-DC converter that steps up your 12V electrical supply to 48V) after shutdown to keep the oil warm, keep its viscosity low, and maximize the oil flowability to purge the oil from them. It has worked very well. It is an excellent preventative measure. The newest flashes addresses improved troubleshooting of FICM and related components, but also include some adjustments to "ease" the electical strain produced on the FICM.

 

Bismic Thank You! That is exactly what I was looking for. I've read alot of stuff on this forum and whenever I see your name I always stop and read what you have to say. I appreciate the quick reply. I can now understand why a full synthetic oil, or oil additive will help prevent this issue.

When you talk about flashing the computer I assume that by getting an SCT with custom tunes it will do the same thing? Or am I thinking incorrectly?

 

An SCT will not flash the FICM, which is where the inductive heat programming "happens".

 

Subscribing.

 

Great explanation of stiction, technical & understandable. You are an asset here !!!!!!!

 

Bismic... Any idea how long ago the reflash you are talking about came out? And how much it cost to have the dealer reflash the truck?

 

The last reflash to "repair" the extremely aggressive inductive heat flash came out in Dec. 09. It also included some additional engine monitoring parameters and another "detune" of the PCM. The engine strategy will be read as a VXCF9.

 

How would you read the engine strategy?

 

Not sure about IDS, but I think AE and I know an SCT tuner will read it.

 

had mine reflashed a while back, and noticed a drop in max boost, and an overall drop in performance and fuel mileage, not much, but noticeable. I think that's the only drawback, it has more pluses than minus's. If your EOT-ECT delta exceeds 15 degrees, it will light the wrench light on the dash, I think somebody on here said it raises the temp threshhold for inductive heating of the injector coils to lessen the strain on the ficm, and there's a few other things that just make the truck run better and more reliably.

 

I'm thinking about getting an SCT tuner but please forgive the ignorance what is IDS and AE??

 

IDS is what the dealerships use for their diagnostics. Auto Engineuity is an aftermarket diagnostic program available to the general public. I don't recall what IDS stands for.

 

Thanks npccpartsman! Now I have something else to check once I get my SCT. I appreciate all the help.

 

Looks like it's time to do an educational post on stiction...