Why is my car overheating when it has coolant?

My wife’s car overheated yesterday, and I insisted she must be low on coolant, but when I checked, the coolant levels were fine. Boy, did I feel foolish! We live in Maine, so it’s certainly not scorching outside. How can a car overheat if it has coolant?

Find out if you’re getting ripped off on your car insurance in less than two minutes.
No spam · No long forms · No fees
Find savings (100% Free)
rating white
3.5k Ratings
Answer provided by
Laura Salvas
Answered on Apr 21, 2022
There’s no worse feeling than being wrong even when your logic was totally right! You’re correct that loss of coolant is a common cause of overheating and that the mild Maine weather likely played no part in this, but if your coolant isn’t circulating properly, then it won’t cool down your car.
If your car is overheating, but it has coolant, these are some possible reasons:
  • Bad water pump. The water pump keeps the coolant circulating through the engine, so if it stops working your coolant won’t circulate and can reach boiling temperatures.
  • Clogged radiator. After it passes through the engine, coolant cools down as it passes through the radiator. But if your radiator is clogged, coolant can’t pass through to cool down and will stop working effectively.
  • Faulty thermostat. Coolant starts to flow through your car once the engine reaches a certain temperature. If your thermostat gets stuck when it’s closed, it won’t open to allow coolant to start flowing.
  • Poor airflow. If your cooling fan breaks down or the grate on the front of your car gets clogged with debris, this can stop air from circulating across the radiator, and your coolant won’t cool down as efficiently.
Driving an overheated car can cause damage to the engine, so it’s important to take care of the problem. Checking the coolant levels was the correct first step to take. If you can’t diagnose the problem from the list above, you’ll likely want to bring the car to a mechanic.
In the meantime, make sure your car is protected with quality car insurance at a great price. You can compare policies from top insurers in mere moments with Jerry. Just answer a few quick questions (no long forms!), and in less than a minute, Jerry will show you the best policies at the lowest rates. The average Jerry customer saves $887 a year.

Here to save on car and home insurance? Great, you do that. We’ll do everything else.

Sign up in under a minute.
No need to fill out forms or shop around. Sign up in 45 seconds to start saving. Jerry does the rest.
Jerry collects and analyzes your current coverage.
Say hello to Jerry, your new insurance agent. We’ll contact your insurance company, review your current plan, then find the coverage that fits your needs and saves you money.
Get the best options before your renewal.
Jerry does all the picky, busy work by comparing prices and coverage from more than 50+ insurance companies. We compare what we find to your current policy and offer you the three best options before every renewal.

Easiest way to compare and buy car insurance

√
No long forms
√
No spam or unwanted phone calls
√
Quotes from top insurance companies
Find insurance savings — it's 100% free