Replacement thermostat stuck open also??
As I'm sure you've seen in my other threads, I rebuilt my cooling system a couple of weeks ago. Replaced LIM gaskets, plenum, radiator, water pump, repaired heater hoses, elbow o-ring, you get the picture. Afterwards, I had al the symptoms of a stuck open thermostat. I should mention I did break the clip on the coolant temperature sensor, but it'* a very snug fit and seems to be working properly. I plan on replacing it, but I don't think it'* the cause of these problems. So if the car were moving, temperatures would not increase. If I hit some traffic, the temperature would go up as expected if the thermostat is stuck open. So I went and bought a new one, drained just a bit of coolant and installed the new one. I did not use the gasket because the intake part of the thermostat housing has some minor damage so the gaskets have always seemed to leak on me. So I just used some thermostat/water pump gasket maker and let it sit overnight. Start it up the next day with the rad cap off, temperatures slowly increase as it should. Hits 195, the coolant level in the radiator drops since the thermostat opens and it fills the upper rad hose from where I had drained it to install the stat. So I'm happy, let it run a few more minutes to make sure temperatures don't continue to rise, all is well. So I put a NEW radiator cap on since the other was the original from what I could tell, and take it out for drive the next day. All the symptoms of a stuck open thermostat again!
Did I get a defect or is there something else that could be causing this? Is not using the gasket somehow making this thing get stuck open? Like maybe a small lip of silicon formed inside the opening when it was compressed and the thermostat is stuck on it? I really don't think it is the temp sensor connection since it cycled right when it read 195 when I was testing it.