It sounds like the engine cooling system thermostat is stuck open; I would remove it to help confirm the failure. Did you run the codes? Also, you may have a defective fuel injector which leaks which can cause poor running for a short sit. I would remove the spark plug to see if there is a dark one which will be the cylinder that is having a problem. Here is how to change the thermostat.
1. On models equipped with airbag system, refer to Technician Safety Information for system disarming and arming procedures.
2. Disconnect battery ground cable.
3. Drain coolant from radiator.
4. Disconnect thermoswitch electrical connector, then the upper radiator hose from thermostat housing.
5. Remove thermostat housing and thermostat from engine assembly. Note installation position of jiggle valve before removing thermostat.
6. Reverse procedure to install, noting the following:
a. Ensure thermostat housing sealing surfaces are free of old gasket material.
b. Install thermostat with jiggle valve positioned at 12 o'clock.
c. Tighten thermostat housing retaining bolts to specification.
7. On models equipped with airbag system, refer to Technician Safety Information for system disarming and arming procedures.
https://www.2carpros.com/articles/how-an-engine-thermostat-works
Please go over this guide and get back to us.
Monday, December 11th, 2023 AT 9:28 AM