Okay, I am quite literally at a loss here. The van started overheating one day, and I have not been able to figure out what is wrong. I changed the thermostat, waterpump, changed radiator cap, flushed the radiator, checked all of the hoses for kinks and possibility of collapsing hoses and what not. Everything seems alright, but it still keeps overheating. Oh, and I also let the vehicle run on an incline with the radiator cap off to "burp" the system.

Alright, on to the odd part. If the van is sitting in the driveway idling, it is just fine. No overheating, thermostat works as it should yadda yadda. But after replacing everything, I took the vehicle out and drove it around the neighborhood a few times, and took it out onto the Pkway. I circled that route like 4 times, and the vehicle was operating at normal temps, and then all of a sudden the temp needle spiked and blew a plastic T fitting that is part of the routing to the heater core. See picture.

I really wish someone could help me figure this out. I am stumped!

 

Most likely you have a blown head gasket.

Do a compression test to see if one cylinder or two adjacent cylinders give you a low PSI reading.