Damon

An ICP related issue like aeration or cavitation would cause a hard restart, extended crank and rough run both before the stall and after restart. I'm with Aaron here, I think the screens in the sending unit module are clogged. We see a LOT of these nowadays. That's not the "sock" since it uses a suction strainer screen and there are 2 tubular screeds inside the sender module itself. Unknown to many, there's also an integral (and NOT replaceable) fine mesh screen on the rail mounted fuel pump inlet too.

I haven't gotten to cut apart a clogged one, but I did get pics and got the stuff back out and dried it out to see what it was. It took several days to do.... Here's the cooler as removed: And the condensed sludge: And the sludge dried: That's all it takes to clog one of these.

No clue what caused it, really. What's odd is that it didn't seem to touch the tape or convoluted tubing. This truck runs as you see here....no codes, no symptoms.

I had an 04 F sereis that has the harness melted by what appears to be chemical damage. I'm not at all sure why, and the customer has not yet opted to replace it. The FICM area looks the worst.

Some stuff you can buy, other parts are restricted items. Basically, if it's the same part as that found on the VT365, then it's OK to get from IH. Many parts are NOT the same, and despite a good IH part number, you cannot source those "ford only" parts from IH.

Kinda what I was expecting. Thanks!

Name some variables that can't be cross-checked and validated by the other sensors.

Of course it does. J1667 makes that kinda obvious. Why else would we be using opacity to emissions test vehicles that weren't really certified to an opacity standard? Do you think that the aftermarket cooler somehow alters emissions levels? To me it looked like an 03 style cooler for the 04-newer style engines. It is fun to try to think about the results we might expect if we cooled EGR too much or too little, however....

I think we're in agreement here, but it's hard to glean from your words. The OBDII operation summary makes clear (to me) that the EGR system is monitored and operated in part by comparing MAP to the speed density calculation. That makes IAT2 a big player, since it's very important to speed density calculations. I agree that the necessary variables can be inferred from the sensors already present. The lack of direct reading makes these existing sensors really important. And I think that the gooped IAT2 will add EGR, which I think is what you were alluding to.

I think the IC4 is available direct

The low coolant probe on the older IH's had this issue too. The probe needed too much current to work, and the result was corrosion on the tip of the sensor. The TSI was to install a module to take the load off the sensor. It's really just a small solid state relay.

I can't reach the same conclusion. The same operation summary says: Quote: The Delta Pressure Exhaust Gas Recirculation (EGR) System is a closed loop EGR Valve Position control system. It utilizes an exhaust manifold pressure sensor, an intake manifold pressure sensor and a speed density estimate of total mass flow and derives a desired EGR Valve position based on a desired EGR flow percentage Can this speed density estimate be accurate without knowing the temperature of this air? IAT alone can't do that. Quote: The EGR Monitor is a series of electrical tests and functional tests that monitor various aspects of EGR system operation. When normal EGR rates are being commanded and when the engine enters into either one of two specified operating ranges, a flow check is performed. The operating ranges are defined to insure an adequate amount of EGR is being requested to allow for an accurate estimate of the EGR flow percentage. At this point EGR flow is estimated based on the difference between the Mass Air Flow (MAF) sensor reading and the total mass flow calculated by the speed density calculation. The estimated EGR flow is then compared to the expected EGR flow to determine if there is insufficient or excessive flow. Even for a P0401 or P0402 monitor to run, the following sensors must be OK: Intake Air temperature Sensor 2 (IAT2). Mass Air Flow Sensor (MAF) Barometric Pressure Sensor (BARO) Intake Air Temperature Sensor (IAT) Engine Oil Temperature Sensor (EOT) Manifold Air Pressure Sensor (MAP) Exhaust Pressure Sensor (EP) Exhaust Gas Recirculation Position Sensor (EGRP) Exhaust Gas Recirculation Valve Actuator Monitor (EGRAM) Electronic Variable Response Turbocharger Actuator (EVRT)

So then why would you believe that IAT2 would be used instead of IAT for disabling EGR in extreme temps on a 6.0? I mean if IAT2 was frigid cold, it couldn't possibly have any EGR to disable. if it was too hot, it probably couldn't disable it anyway.

The 6.4 has an EGRT inlet and outlet sensor, so the function of IAT2 wouldn't be needed for any part of EGR control until something went wrong elsewhere.

Yep, it does that too. But oddly, you don't see these sensors on many aftercooled engines that don't also have EGR valves. So it stands to reason the primary function of this sensor is for emissions control feedback. Remember: We don't have anything in the exhaust system, this all needs to be inferred.

Precisely my point. I can't say I've seen a skewed or failed IAT2, but we've all seen heavily insulated (and therefore lazy)ones. THAT just *MAY* cause a bit more EGR than we'd have otherwise.

Thanks for at least a partial vindication. I see all Ford's references to this sensor as being used to measure manifold air temp but it falls short of saying what for. IH makes no mistakes about it though. It still won't cause an EGR cooler to fail, but it is an integral part of the EGR system, IMHO.

For the purpose of the discussion..... I understand the IAT2 sensor is used (in part) to detect EGR flow. Is this incorrect? If so, would it NOT stand to reason that a fouled IAT2 sensor might cause overactive EGR due to the slow response of the sensor due to the carbon buildup? Forgetting the BS of boiling coolant due to IAT2, there's at least the appearance of some merit to the theory that a lazy IAT2 might cause the EGR to be open longer than would be otherwise, thereby increasing the need for greater heat exchange in the cooler. That, combined with a clogged oil cooler, could cause the EGR cooler to fail.