I just replaced my radiator yesterday because my old one was leaking. It was also plagued with the Dextron crud so I figured I would kill 2 birds with one stone by replacing the radiator and do a coolant swap at the same time. After the swap, I tested it out by letting it warm up while monitoring the temp. It went up to 196 and then dropped down to stay between 192 and 196. Today I took it out for a little drive and logged about 30 miles. Temp stayed below 1/2 (around 3/8 where yesterday I was reading 195ish) on the gauge and I didn't have my scanner with me to check while I was out and about.
I went out to let the car warm up again just to check it again since I do a lot of highway driving and I'd rather not break down when I'm 40-50 miles from home. While the car was warming up (about 1/4 on the gauge), the upper hose was already feeling hot. If I understand it correctly, the upper hose shouldn't really get warm until the thermostat opens at 195. I was a little confused about that. The temp was still rising and when it got to 180 the upper hose was burning hot. Right after that I noticed the upper hose looked like it was bulging and like it might pop. At this point the temp was up to 195. I let it go another minute and the temp didn't go any higher.
Here's a pic of the hose. Does anyone have an idea what is going on? With the upper hose getting hot, I'm thinking it might be a bad thermostat. Would the bulging hose mean a clogged radiator? When I flushed it, water didn't seem to have any problem running through it.
img_5339 (8).jpg
