Q: "H" temp reading

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My temp / oil gauge is reading "H" . . I have oil and coolant both in car . . my mechanic needs to fix one of my 6 catalytic converters . . . would this be related? . . . is my car dangerous to drive?

My car has 100000 miles.
My car has an automatic transmission.

When it comes to the cooling system, there are other components that can fail which would cause the temperature to rise. Even if your coolant is full, if the thermostat will not let enough pass through, the system will not be able to complete the heat transfer process. In this situation, I recommend you start there. If the thermostat tests to be good, you will want to look to the radiator for any time of damages. The radiator can be cracked, have bent fins, or be clogged just to name a few of the common problems. Secondly, a failed water pump would not circulate the coolant. The cooling of the coolant once it absorbs the engine heat will not take place. As far as driving the car while it is overheating, it is dangerous for the engine. Stalling or breaking down while on a busy road can also be dangerous. Never drive the vehicle when it reaches "Hot". Once your vehicle reaches 280 degrees Fahrenheit the engine damage done can be unrepairable. Have this checked out immediately, or do a visual inspection yourself and see if you can make the repairs.

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