A MLK day panic

Today is a day off for me, and being that it is rather warm for January (almost 40 degrees) so I thought it would be a good day to do a couple minor fixes on the Cutlass Ciera. The last time I ran the car I noticed a couple leaks had appeared. The Cutlass was leaking a little trans fluid and good amount of antifreeze. A quick inspection showed that it was just a couple loose hose clamps that were causing the problems. The trans was pretty minor so not sure if we just never noticed before or if it loosened a bit after a couple races. The radiator hose was loose from where it connects to the radiator from the thermostat. Some corrosion go in there making it seem like it was tight when in actuality the hose was barely on. I don't recall removing that hose when I switched the engine back to antifreeze after the race although I do know I removed it when switching over to water. This make me wonder if the car ran the whole race with that hose barely on. Well I guess a barely held on hose is not something to really worry about after the race was is over. A couple turns of screw driver and they're both fixed. So check the fluids and they're all good. Well the trans seems a bit thin and runny but the in radiator trans cooler leak is something that can wait for better weather. Start the car up to let all the fluids flow and cover the stuff that needs covering. It starts right up and I walk away to do something quick. When I walk back I look at the gauges and see its up over 2/3 the gauge, a bit higher than normal but OK, so I turn on the heater to make sure the heater core circulates. This normally drops the temp pretty quick but it seems to do the opposite and puts it right near the red. I real I stick my head over in the engine bay and see the fan hasn't kicked on. Well crap, but this is why we put the switch in the cabin. I flip that and the gauge goes all the way to the right in the bad area. I real quick flip it off worried something awful is happening. fan still spinning I start looking things over. Check the exhaust and there doesn't seem to be water coming out so that is good. Next check the radiator outlet hose and its cold. Did the thermostat break? We got the fail open type but I guess breaking doesn't mean it will break correctly. Touch the engine and its warm but definitely not hot. I check the gauge again and see it wildly swinging back and forth, from the red to slightly less, then all the way past where the guage reads and then back to about 250. Well that doesn't make sense, that the temp would go all over the place when the engine isn't running. Looks like I should check some things. The in hose from the radiator is warm but not hot. I check the oil cooler lines and they're both cold. So either the thermostat, oil filter bypass, and the temp sensor for the ECM which controls the fan all failed at the same time, or the temp sender sensor for the gauge is flaking out. (not sure about how gm does it now but on this engine there is a completely separate sensor/sender that is used just for the gauge which in a case like this is nice since you would have several separate things that would need to fail to really damage the engine> Since we had to swap it out to a sender/sensor I knew exactly where it was. its right under where Duff like to nap.

When looking at it I noticed that the pair of wires run really close to the EGR line. Between the first race I had rerouted it a bit after seeing the wires getting a bit discolored from heat. When I looked at it again it was rather close to the EGR again, and guessing that since that exhaust gases would be hot that it might be messing it up. So I unplug it, blow into the connector since that always worked with Atari games, rerun it again and check the gauge again. The temp dropped straight away and when I start the car again it is down about 100. And while the car ran everything seemed to go as expected. The Temp slowly rose till 185 where it dropped again when the thermostat opened and the hose warmed up. after running a bit more one of the cooler lines warmed up. the line back to the engine didn't really warm but that's probably caused by the fact that the cooler is cooling the oil(go figure). It ran for a while and is back to its normal since the cooler was put on not wanting to warm up much. So I guess I'll have to put the sender on the list of things to look at this spring in case we have to spend the $15 for a new one.