I am not sure why you replaced the coil packs but if the issue did not exist before you changed the check all the connections. This is an electrical issue. If the problem existed before the coil change. Start checking the ignition system as it sounds like your start/ run circuit is being disrupted. This circuit can also effect the fuel system. One other question! Did you replace your fuel pump with an after market type. If so replace it with an AC Delco pump as after markets have issues of not maintaining the pressures once warm. Hope this helps you solve your issue.
when a temp gauge drops to cold ,it indicates a problem in the cooling system
temp gauge sender units need water to activate the resistance that makes the gauge read so a falling gauge indicates no water around the sender unit --- air lock in the system--faulty wire connection to the gauge sender unit
the ac unit is not connected to the temp gauge so there may be another separate problem there
the temp sensor is an entirely different unit to the temp gauge sender unit and the short term working would be from an altered coolant level from changing that sensor --air lock in system
the temp sensor connects to the ECM to activate the fans and monitor engine operating temp so as to keep the air/fuel mixture exact for the engine conditions
the temp sender unit just makes the temp gauge read
a faulty thermostat will either be stuck open and the engine temp will take a long time to rise or it will be stuck closed and that will cause an overheat very quickly
With your jack there is a black bag. In the bag are metal poles connect together and insert in slot near rear license plate. The pole is your handle that you insert into the winch to lower you're spare tire. There is a hole above the bumper but bellow the tailgate the you need to insert your made pole into then turn counterclosewise to lower
It's most likely due to a clogged PCV valve or clogged/kinked PCV hose. I'll include a video showing PCV system operation.
I've seen this symptom many times on various engines, and the PCV valve was usually clogged/defective. A clogged PCV valve results in crankcase pressure build-up and fumes/oil exiting places on the engine that it shouldn't. A severely clogged PCV often makes oil leak/exit out of the dipstick, even with dipstick in place.
The good news is... if the PCV valve is clogged/defective, the "cure" is a very cheap fix. Usually less than $5.
PCV stands for Positive Crankcase Ventilation, btw.
But note that on some engines (those where the oil filler opening is directly above the rocker arms/valvetrain) it is normal to have a small amount of oil "spray" come out, as the rocker arms are dispersing oil thru their oil passage hole on top.
(Whenever posting vehicle questions, always please add the engine size/type. It helps in more accurate diagnosis.)
Also, please rate via the helpful button if you feel my answer helped you out. Also post back and let me know if this cured it.
check that the wire to the temp sender unit has not fallen off or is not making good contact. If the dash reading is saying that the ac system is off then check that ac system for operation and gas supply. If thermostats are faulty they normally fail in the closed position so there would be an over heat problem with in 10 minutes of stating the engine so at this stage I would leave the thermostat alone
