If the thermostat becomes stuck in the open position, there is continuous flow of coolant into the radiator causing the engine to run cold. Overcooled engines run inefficiently, which leads to increased fuel consumption and higher emission levels and engine parts enduring more wear.

What happens if you drive with a stuck open thermostat?

If your car is running unusually cool and not building up any heat in the engine, it’s likely that your thermostat is stuck open and is letting too much coolant through. A thermostat that is stuck in the closed position will cause your vehicle to overheat.

Will a stuck open thermostat cause overheating?

A stuck-open thermostat can also cause lack of heat from the heating system. The Check Engine light may come on too. Thermostat stuck closed: When the thermostat is stuck closed, the engine might overheat. Besides these two cases, the thermostat may also need to be replaced if the thermostat housing is leaking coolant.

Can a stuck open thermostat cause rough idle?

No. An open thermostat would just let the engine run cool all the time, making your heater useless.

Table of Contents

What would cause a thermostat to stick open?

Stuck open means too much coolant is being allocated to the engine, causing the engine to be abnormally cool. If the thermostat is stuck closed, that means not enough fluid is going into the engine and the engine will overheat.

How do you tell if you have a stuck thermostat?

Checking For the Signs of a Bad Thermostat Look to see if the coolant is swirling/flowing immediately — that means the thermostat’s stuck open. If the coolant doesn’t flow after 10 minutes or so and continues to be stagnant after the temperature gauge indicates it’s hot, the thermostat’s likely stuck closed.

Is it bad to drive with a stuck thermostat?

Can I Still Drive with a Bad Thermostat? The easy answer to this question is no. While your car may be physically able to move and get you from Point A to Point B, you will want to refrain from operating your vehicle. This can lead to more parts of your vehicle being damaged, especially if the engine is overheating.

Can you drive a car with bad thermostat?

Most automobile mechanics will tell you it is not a good idea to drive your car without a thermostat installed. If your thermostat becomes stuck in the closed position, though, this will cause your engine to overheat and make driving your car impossible.

What happens if engine runs too cold?

If you run your engine cold all the time, you’ll most likely experience increased fuel consumption across the board. Additionally, you’ll find higher amounts of carbon buildup at various parts of the engine. The most damaging effect of feeding a fuel-rich mixture to the engine is excess fuel reaching the exhaust.

Can a bad thermostat cause a rough idle?

Registered. A bad thermostat can cause your engine to overheat when stuck closed or make it take a really long time (if ever) to get up to operating temp when stuck open. I don’t think it can cause a rough idle by itself.

What are the symptoms of a thermostat going bad?

5 Symptoms of a Bad Thermostat (and Replacement Cost)