Quote from: AJP turbo on June 24, 2017, 01:43:09 PM
Who changed the coolant? Did you have the system vacuum bled? It doesn't sound like the boost is overly high to give coolant temp problems....Everybody claims the intercoolers in the F150 to be too efficient so I'm not thinking you have an intercooler problem either
Sorry about the delayed response. I guess I need to setup my notification settings...
The dealer changed the coolant 9k miles again when they did the timing chain and phasers under warranty. I don't know if they vacuum bled it at that time.
I don't buy that the F150 intercoolers are efficient. On the way through Nevada, I setup my SCT tuner to display cylinder head temps and IAT2. While cruising at 70mph towing the 6000lb trailer, the IAT2 would be 20-30* above ambient (it was 95* out). When on an incline, the boost would rise above 8psi and the IAT2 would go upwards of 150*. When it crossed 130*, the cylinder head temps would rise quickly and if I didn't let off the throttle and slow down, I would get a display on the dash stating "engine over temp" and "reduced power." The coolant gauge on the dash would be pegged at full hot. It would drop instantly when I let off the gas, but the IAT2 took a long time to come down, leading me to believe the intercooler was heatsoaked. When I pulled over, there was no difference in temps between the turbo side and the intake side of the intercooler. It was equally hot.
I had hours upon hours to observe this and the IAT2 was clearly unmanageable above 8psi. I was able to predict at what point the intercooler would heatsoak and at what temps the cylinder head temps would rise. Sometimes I had to go 50mph to keep temps in check even though I was confident the truck could pull at 80mph.
This was super frustrating considering I have the max tow package. The truck should be able to tow 10,500lbs stock and with a dynoed 294HP and 449Tq at the wheels (at 5k' above sea level), I could barely tow 6000lbs in that heat. In Utah I got so frustrated that I pulled over. I opened the hood and was reminded of the silly band aide Ford placed on the 2012-14 intercoolers to mitigate the condensation issue. They basically blocked off the top 1/4 of the intercooler, raising it's temp so that humidity would stay in a gaseous state and flow through the intercooler instead of collecting in the bottom and then being coughed up into the engine every once in a while causing the infamous stutter.
So I tore off the plastic blocking the top of the intercooler and guess what. The problem was solved, mostly. I could tow in 90*+ heat at 70mph without spiking IAT2 or cylinder head temps. Steep inclines would drive the IAT2 up, but it was much more manageable. When the ambient temps increased to 100*+, I again had to be careful, but it still was not nearly as bad as with the demoralizing intercooler blocking plastic.
When I got home, I searched the internet and found that overheating when towing is common with these trucks because of the crappy intercoolers. So I'll be upgrading to an aftermarket intercooler for a larger margin of safety. It sounds like one of the TSBs that came out from Ford for the stutter instructed service centers to install the intercooler blocking plastic.
The other thing is, there is no ducting or air control from the factory to direct air through the intercooler. If you look at where the lowest pressure areas are around the intercooler, there is no reason why air would pass through the intercooler. It would want to go below it and exit under the truck or around it and into the engine compartment. Mishimoto created an upgraded intercooler with attached air dams to control the flow of air into the intercooler.
So that's the story. I took some logs, but really the problem was so clear that could see it just from hours in the truck. I hope this helps someone else who's scouring the internet for answers.