Can I use water instead of coolant to get home?

AAA's guidance is not to keep driving. Some AAA clubs describe adding water once an engine has cooled as an emergency measure, and the same guidance warns not to remove the radiator cap while the coolant is still hot, because it can spray out and severely burn you. Getting the car towed avoids the question.

How do I know the puddle is coolant?

Coolant is usually bright — green, orange, pink or blue — and slightly sweet-smelling, while engine oil is dark and transmission fluid is red. AAA lists coolant leaking onto the ground as one of the signs of an overheating problem, alongside steam, a burning smell and the gauge in the red.

How much does a coolant leak cost to fix?

AAA says a simple coolant leak repair might cost a few hundred dollars, and the real answer depends which of its eight overheating causes is behind it. RepairPal publishes $1,361 to $1,541 for a radiator replacement and $885 to $1,134 for a water pump — two of the common ones.

Can I drive with a coolant leak?

Published August 21, 2026

AAA's published guidance for an overheating engine is to pull over safely, turn off the engine, move somewhere safe and call roadside assistance.

AAA is direct about the alternative, and it is the sentence to carry away from this page: attempting to add coolant to your vehicle yourself and continuing to drive is dangerous and can cause severe burns and potentially thousands of dollars of damage to your vehicle. That is AAA's wording, not a paraphrase. The burns are the immediate risk — a cooling system that is hot is also pressurised — and the damage is what happens to an engine run without enough coolant in it.

Source: AAA

This page is general information, not professional advice. It cannot see your car and does not diagnose it, and the only judgement that counts is from a technician who has looked at it.

What AAA says to do when the temperature climbs

Pull over safely, with the hazard lights on as you slow down.
Turn off the engine as soon as you are stopped, to prevent additional damage.
Get out with any passengers and move somewhere safe, away from traffic.
Call roadside assistance for a tow to a repair facility, rather than driving on.

Those four steps are AAA's, in AAA's order, from its guide to an overheating engine. It also lists what a driver notices first: steam or a burning smell from under the bonnet, the temperature gauge in the red, a loss of power, and coolant on the ground. AAA describes the smell of burning coolant as sweet, which is a useful thing to know because it does not smell like anything else a car does.

Source: AAA

A leak is a symptom, and there are eight of them

AAA's list of what makes an engine overheat runs to eight: a coolant issue, a thermostat failure, a damaged radiator, a faulty serpentine belt, a malfunctioning water pump, a clogged or leaking coolant hose, a blown head gasket, and a low oil level. Several of those show up as a leak and several do not, which is the reason a puddle is not a diagnosis. A cracked radiator cap is on AAA's list of radiator faults, and it is one of the cheapest things on a car.

Source: AAA

Coolant on the ground and a car that has not overheated yet is the good version of this problem. It is a booking, not an emergency — but it is a booking.

What the repairs behind a coolant leak cost

It depends entirely which of the eight it is, and the spread is wide. RepairPal publishes $1,361 to $1,541 for a radiator replacement and $885 to $1,134 for a water pump. AAA, describing the cheap end, says a simple coolant leak repair might cost a few hundred dollars — and describing the expensive end, that ignoring one can lead to overheating and then to a cracked engine block or blown head gasket, which it puts at over $1,000. RepairPal publishes $2,538 to $3,337 for that head gasket.

Sources: RepairPal, RepairPal, AAA, RepairPal

Price the specific repair against the published tables: the free car repair estimate calculator.

Questions people ask next

Can I drive two hours with a coolant leak?: No page can answer that for your car, and AAA's guidance does not draw a distance. What it does say is that adding coolant yourself and continuing to drive is dangerous and can cause severe burns and potentially thousands of dollars of damage, and that its four steps for an overheating engine end in a tow rather than a drive.
Can I use water instead of coolant to get home?: AAA's guidance is not to keep driving. Some AAA clubs describe adding water once an engine has cooled as an emergency measure, and the same guidance warns not to remove the radiator cap while the coolant is still hot, because it can spray out and severely burn you. Getting the car towed avoids the question.
How do I know the puddle is coolant?: Coolant is usually bright — green, orange, pink or blue — and slightly sweet-smelling, while engine oil is dark and transmission fluid is red. AAA lists coolant leaking onto the ground as one of the signs of an overheating problem, alongside steam, a burning smell and the gauge in the red.
How much does a coolant leak cost to fix?: AAA says a simple coolant leak repair might cost a few hundred dollars, and the real answer depends which of its eight overheating causes is behind it. RepairPal publishes $1,361 to $1,541 for a radiator replacement and $885 to $1,134 for a water pump — two of the common ones.

Written for drivers by Most Recommended Auto Repair, which measures which auto repair shops AI assistants actually recommend. Nobody can pay to be on those lists. How we measure.