PT Cruiser, replaced radiator and thermostat, dashboard gauge reads normal but car is running hot and having to add coolant daily

ANSWER : Hello, thank you for writing in. The vehicle is reading normal temperatures because the fluid temperature sensor needs to be in the fluid to give an accurate reading. The second there is a leak and the fluid level drops, that sensor is reading air, and the gauge is giving a bad reading. Coolant leaks can be internal or external. For that reason, you must not rule out the option that your vehicle is consuming the coolant. This most commonly happens when you have a bad head gasket. In this case you will usually find white smoke (steam) coming from your exhaust. The leak must be at least partly external, because of the puddle you are finding. The only way to resolve the issues is to find and fix that leak. A dye test may be your best bet, which you can do at home with the right tools, or by a technician. For more help with finding and fixing the leak, contact our service department to schedule an appointment.

ANSWER : It’s possible that your temperature gauge is operating erratically which would be an electrical problem (sending unit, gauge, wiring, etc.) rather than an actual overheating problem. The most common causes of overheating include low coolant level, a faulty thermostat, a plugged radiator, a faulty radiator pressure cap, collapsed hoses, non functioning cooling fans, and a faulty water pump or drive belt. Certain engine faults, such as a leaking head gasket or poor engine running condition can also cause overheating. Whether the problem is gauge related (electrical) or actual overheating, if you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine overheating diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : There could be an issue with the cylinder head gaskets. Antifreeze can break down and become acidic if not replaced as normal maintenance. The head gasket material erodes and can cause engine compression to build up in the coolant system. This will prevent the flow of coolant which can create an overheating condition.

There is a test that can be done to check whether there is carbon monoxide in the coolant system; it involves special equipment.

I recommend having your overheating condition inspected, and perhaps have a block test performed.

ANSWER : Hello, thank you for writing in. Everything that has been done was valid in trying to trace down the issue. You likely did your vehicle a lot of good in updating those cooling system components. With that being said, one of the only components you did not mention testing is the cooling fans. Without air flow over the radiator the coolant does not lower in temperature before going back into the engine. When you are driving the air flow is steady, but when you idle (or reach a certain temperature) the cooling fans must kick on to help. For more help with testing and repairing the fans, contact our service department to schedule an appointment.

ANSWER : The engine temperature should be measured independent of the dash gauge and/or a scan tool should be used to read the temperature sensor directly to determine what the operating temperature actually is. If the car is in fact overheating, it’s best not to drive it because overheating can warp the cylinder head and/or engine block causing costly damage. The most common causes of overheating include low coolant level, a faulty thermostat, a plugged radiator, a faulty radiator pressure cap, collapsed hoses, non functioning cooling fans, and a faulty water pump or drive belt. Certain engine faults, such as a leaking head gasket or poor engine running condition can also cause overheating. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine overheating diagnostic and the responding certified mechanic will get this resolved for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hi there. Most of the time, overheating issues are caused by a radiator leak, leak in the coolant lines, or a failed thermostat. The worse case scenario is that you’d have a blown head gasket.

However, if you’re seeing small drips on the ground, the leak could be coming from one of the hoses, which might also introduce air pockets into the coolant line. This could be what’s causing your overheating situation. However, it might be a good idea to have a local certified mechanic stop by your home to do a complete cooling system inspection. That could save you a lot of money instead of replacing parts that you are unsure are faulty.

ANSWER : Hello, high idle can be represented by many conditions. A heater core would not cause this unless you have a coolant leak and the core was leaking. There are tests that can be performed to test a water pump (coolant pump). A vacuum leak can create high idle and even a high engine temperature. A suggestion is to read engine data and any fault codes in the system. This is done with a scan tool. The scan tool can read data which will give you information on the operating systems of the vehicle. If you’d like, a certified technician from YourMechanic can come to your location and do a complete evaluation of the overheating issues.

ANSWER : Hi there. For the coolant light to go out, you would need to have the coolant between the low line and the full line for the light to go out. If the coolant is low and keeps on being low, then look for any signs of coolant leaks. You may have to use a coolant pressure tester to pressurize the reservoir to allow the leak to be found.

If you need further assistance with the coolant being low and the warning light being on, then seek out a professional, such as one from Your Mechanic, to help you.