Originally Posted by Suds1959
Only happens when towing......
This started happening very random and now it is regular.. It sometimes happens even when on level road.
You need some gauges like the Edge Insight CTS or the scanGaugeII but i think your problem is your oil cooler is getting pluggged form 1. Casting Sand 2. Silicates drop out from the Ford Gold junk coolant you need to check the deltas (difference) in ECT-EOT max is 15* if you keep going you may blow the egr cooler need gauges. I did not wright this but i read it alot.
The 6.0 is known to blow head gaskets. This is why it happens. The Ford Gold coolant contains silicates. The silicates are not able to handle high EGT's generated by a good load or relatively high boost when run through the EGR cooler. They break down into a jell like sludge and fall out of suspension. This crud gets caught up in the tiny coolant passageways of the oil cooler. As the cooler clogs up it restricts coolant flow to the egr cooler. Now the egr cooler doesn't have enough coolant to carry off the heat generated by high EGT's. The limited amount of coolant in the egr cooler flash boils causing high pressure in the cooling system and the truck pukes coolant from the degas bottle due to the pressure. (it has to go somewhere)
Your uninformed Powerstroke owner is not monitoring his coolant temps and oil temps so he doesn't know whats going on and he keeps driving it this way. The problem get worse, the pressure causes the egr cooler to rupture. Now the egr cooler is leaking coolant into the intake manifold which then runs into the cylinders. Again the high combustion temps cause the coolant to vaporize. This causes unacceptably high cylinder pressure, the TTY head bolts stretch due to the additional pressure and there go your head gaskets.
Ok now you know the problem. Here's the cure. Get a good engine monitoring solution like the Edge Insight so that you can monitor your ECT and EOT. If those temps get more than 15* apart at normal cruising when at normal operating temperature your oil cooler is clogging up. Rebuild it now to prevent all that down stream damage from occurring. Flush that Ford Gold coolant cxxp out of your engine with a couple bottles of Restore. This is made specifically to clean out that silicate residue. Now refill it with a silicate free Cat EC-1 rated ELC coolant. This removes the silicates that clog the oil cooler from the equation. If you live in an area where you don't have smog inspections delete the egr system. If you can't delete it replace the egr cooler with the cooler manufactured by Bulletproof Diesel. This is vastly superior to the Ford oem egr cooler and it will not fail on you. If you find that you need to replace head gaskets replace the TTY head bolts with ARP studs and use black onyx (Victor Reinz) head gaskets or stock Ford HG's. If you have to replace the egr cooler always replace the oil cooler. That is the source of the problem.