Found a green, orange, or pink puddle under your car with a sweet smell? That's coolant - and it almost always points to a leaking hose, water pump, or radiator. Here's how to figure out which one and what it costs to fix.
Rubber hoses dry out and crack with age, especially at the clamps. This is the most common coolant leak and the cheapest fix - usually under $40 in parts.
Get Free Diagnosis →Water pumps have a small drain hole on the bottom. When the internal seal fails, coolant drips from there - typically near the front-center of the engine. Plan on $400-700 at a shop.
Get Free Diagnosis →Plastic radiator end-tanks crack with heat cycles. You'll see a steady drip directly under the radiator. Replacement runs $300-700 installed.
Get Free Diagnosis →If you smell coolant inside the cabin or see fog on the windshield with the heat on, the heater core is leaking. This one is expensive - the dash usually has to come apart.
Get Free Diagnosis →White exhaust smoke, oil that looks like a milkshake, or coolant disappearing with no puddle - those point to a head gasket. Major job, often $1,500+.
Get Free Diagnosis →Describe what you're seeing and our AI mechanic will tell you what it is, how serious it is, and what it costs to fix - in seconds.
Get My Free Diagnosis →No account needed. First answer is free. Full report is $5.99.
If your check engine light is on, these codes commonly appear with coolant problems. Click any code for full details.
Coolant is usually bright green, orange, pink, blue, or yellow and has a slightly sweet smell. It feels slick like syrup, not oily. If you put a paper towel on the puddle the color soaks right in.
For short trips, yes - as long as the temperature gauge stays in the normal range and you keep the reservoir topped off. But fix it within a few days. Running low on coolant can overheat the engine and cause thousands in damage.
It depends on the source. A hose or clamp is $15-50. A water pump is $400-700 installed. A radiator is $300-700. A heater core can run $800-1,500. A head gasket is the worst at $1,500-3,000+.
Coolant tastes sweet, so pets lick it up. Even a small amount of ethylene glycol is fatal to dogs and cats. Always clean up coolant puddles immediately and store it sealed.
Tell our AI what you see under your car. You'll know what it is, whether it's safe to drive, and what the fix costs - in under a minute.
Diagnose My Leak Now →