Probably a vacuum leak. Do you have a code P0171 or P0174?
It should reset itself when the coolant is back to the appropriate level as long as the sensor is working properly. If you look in the overflow reservoir and can see coolant, the sensor or wiring might be the problem.
Not as long as the computer detects a problem
The check engine light is on because there is a problem detected. Until the problem is resolved the light will continue to come on. Once the problem is fixed and the ECM is satisfied after a few drive cycles, the light will clear itself.
The Oldsmobile LX5, 3.5L V6 is a (DOHC) dual over head cam, engine. It doesn't have rocker arms, but roller cam followers. The followers itself can fail in the form of a faulty roller, but more likely the hydraulic tappet/slack adjuster that the end of the follower rides on or the valve spring itself is faulty/broken.
Most likely it is a problem with the gas cap itself. Make sure it is closed properly. Most likely it is a problem with the gas cap itself. Make sure it is closed properly.
If you have fixed the problem it should reset itself. If not, the light will stay on.
Repair the problem and it will typically reset itself after 3 starting cycles.
It will automatically reset itself after you have started the car 50 times after the problem was fixed, or sometimes if you disconnect the battery for a while it will reset itself.
The problem has gone away and the computer has passed the required tests enough times.
I had a 1994 mercury villager I was having the same problem it shutting down when the engine got warm. The distributor was the problem . After I changed it I never had another problem with it shutting down anymore. Good luck
The check engine light can be reset two ways. 1) If the problem resolves itself, the check engine light will reset itself after a certain amount of cold starts of the car on the on board computer system. 2) You need an OBD reader that has the reset check engine light capability.
10mm socket. May want to go with the longer socket. A bit of a squeeze either way. It's called a water pump socket. It costs as much as the water pump itself.