> **Quick Answer:** Yes, pull over immediately. An overheating engine can seize within minutes of the temperature gauge hitting red. Get to the right shoulder, shut the engine off, and do not open the hood or radiator cap right away. Continuing to drive risks destroying your engine entirely, turning a fixable problem into a $3,000-plus repair or a total loss.
## Should I Pull Over Right Now or Can I Make It to the Next Exit?
Pull over now, not at the next exit. Every minute you drive with the temperature gauge in the red is burning coolant away and cooking your cylinder head gasket, which is one of the most expensive repairs on any engine. If the exit is a quarter mile away and traffic is clear, fine. If it is two miles, do not risk it.
The one exception: if you are in an active travel lane with no safe gap to the right, you can briefly turn the heat on full blast and turn off the AC. That pulls heat away from the engine and buys you 60 to 90 seconds to find a shoulder or exit. It is not a long-term solution.
## What Do I Do Once I'm on the Shoulder?
Turn the engine off, put on your hazard lights, and stay in the car or get behind the guardrail. Do not open the hood for at least 15 minutes. Coolant under pressure is superheated, and a radiator cap opened too early will spray scalding fluid.
After 15 to 20 minutes, you can pop the hood to let more heat escape. Check the coolant reservoir (the translucent plastic tank near the radiator). If it is empty or close to it, you have a leak. If you carry an emergency bottle of coolant or even plain water, you can slowly top off the reservoir once everything is cool to the touch. Start the engine briefly and watch the temperature gauge. If it climbs again fast, shut it off and call for a tow.
## What Caused My Engine to Overheat on the Highway?
The most common culprits are a coolant leak, a failed thermostat, or a blown radiator hose. On the highway specifically, a stuck-closed thermostat is a frequent cause because the engine is under sustained load at high RPM with no stop-and-go airflow to help cool it down.
Other causes worth knowing: a broken serpentine belt will stop your water pump from circulating coolant, and you will see the temperature spike fast alongside a loss of power steering and the battery warning light. If that combination hits you at once, [a snapped serpentine belt is the likely diagnosis](/serpentine-belt-snapped-while-driving-emergency-steps/). A low oil level can also spike engine temps, so checking the oil dipstick while you are stopped takes 30 seconds and tells you a lot.
## Is My Engine Already Damaged, or Can I Drive It to a Shop?
You may have caught it in time if the gauge just hit the red zone and you pulled over quickly. If you see steam coming from under the hood, smell something sweet (that is coolant burning off), or heard a loud bang or knocking before you stopped, there is likely already damage.
A cracked cylinder head or a blown head gasket does not al
*Photo: Pexels*
ways announce itself loudly. If the car cooled down, restarted, and seems to run fine, drive it five minutes and watch the gauge. If it climbs again, stop and have it towed. Do not convince yourself it is fine just because it started. You need a mechanic to pressure-test the cooling system before you put miles on it. If you end up needing a tow, check [how much a flatbed tow truck costs in your area](/how-much-does-a-tow-truck-cost-with-no-insurance/) so you are not caught off guard by the bill.
## When Do I Need a Tow Instead of a Quick Fix?
Tow it if any of these are true: the coolant reservoir was completely empty and refilling it did not hold, you see an active leak under the car, the temperature spiked again within minutes of restarting, or you heard a knock or bang before you stopped. Those signs point to damage that will get worse the second you put load on the engine again.
If you are stranded and unsure whether your roadside assistance covers the situation, [AAA membership can cover a tow like this](/aaa-membership-worth-it-single-tow-cost-comparison/), and most policies that include roadside assistance will as well. If you have no coverage, out-of-pocket towing on a highway typically runs $75 to $150 for the first five miles, more if you need a flatbed.
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*Photo: Pexels*
## Common Questions
**Q: Can I add water instead of coolant if I'm stranded?**
A: Yes, plain water works in an emergency. It will dilute your coolant mix and lower the freeze point, but it will get you to a shop without causing additional damage. Drain and refill with the correct coolant ratio once you are there.
**Q: Why did my car overheat only on the highway and not in the city?**
A: Highway driving puts sustained load on the engine at high RPM for long periods. A weak thermostat, a partially blocked radiator, or a low coolant level that is borderline in city traffic can tip over into overheating under that sustained demand.
**Q: How long does it take an overheating engine to cause serious damage?**
A: It depends on how far past the red zone the temperature climbs, but a severely overheated engine can warp a cylinder head or blow a head gasket in as little as two to five minutes of continued driving above safe temps.
**Q: My temperature gauge spiked and then dropped back to normal. Is it fine now?**
A: Not necessarily. A gauge that spikes and drops can indicate a failing thermostat opening erratically, a low coolant level, or air trapped in the cooling system. Have it inspected before your next highway trip.
**Q: What does a blown head gasket repair cost compared to just pulling over?**
A: A head gasket repair typically runs $1,500 to $3,000 depending on the engine. On some V6 and V8 engines it goes higher. Pulling over and calling a tow truck costs $75 to $200. The math is not complicated.
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*Need roadside help? Visit [Tow With The Flow](https://towwiththeflow.com/car-overheating-on-highway-should-i-pull-over-immediately/) for real answers when your car breaks down.*
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*Need roadside help? Visit [Tow With The Flow](https://towwiththeflow.com/car-overheating-on-highway-should-i-pull-over-immediately-2/) for real answers when your car breaks down.*
Car Overheating on Highway: Should I Pull Over Immediately?
Photo: Pexels