I have a coolant leak. I’m not sure exactly where. I noticed a small puddle in my driveway and it leaks out intirely in days.

I noticed coolant in my driveway. I refilled and it was empty again in a few days. My car hasn't overheated and drives OK even after an hour of driving around town yesterday. I checked my oil and it's fine, not milky, so it's hopefully not head gasket related. I don't let repairs linger on my car. I would like to have options before I take it to the Ford dealership. Thanks

My car has 180000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Coolant leaks can come from a number of components. The water pump, an external head gasket leak, radiator or hose can be just a few locations for coolant to leak from. The best way to locate a coolant leak would be to pressure test the system. The cooling system relies on coolant added to water and pressure to keep the water from boiling over. Pressure testing the system will force the coolant out, enabling the technician to locate the source.

How to Identify and Fix Common car Problems ?

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If the coolant level is dropping and there is no external leak evident, then the coolant is probably leaking internally, into the engine. If the car has recently overheated then this could have caused the head gasket to fail. If it has, it could be leaking coolant into the combustion chambers.
If you suspect an internal coolant leak, allow the radiator to cool, take off the cap, and look for signs of oil or frothy bubbles in the radiator or header tank. With the engine running, smell the coolant itself – if there is a whiff of exhaust gas , the cylinder-head gasket may be leaking.
The most common reasons a Ford Mustang has a coolant leak are loose hose connections, a broken radiator, or a failed water pump.
Corrosion within the radiator is one of the leading reasons that coolant leaks. As the tubes get older and weaker, you may get sediment or debris inside that causes a leak. The sealing gasket between the tank and the radiator can also wear out, and that could lead to a leak.
Gaskets and Seals

One common place of a coolant leak is the radiator pan gasket. The drain plug can also cause leaking, and if the cap that seals the radiator can no longer contain the pressurized coolant, it will leak or spray out from underneath.

A coolant/antifreeze leak can occur for a variety of reasons, including a blown radiator hose, a bad hose clamp, warped head gasket, or the most common reason, a foreign object kicked up by the truck in front of you penetrating the radiator itself.
Depending on the cause of leakage, you may get away driving with a radiator leak for a short time. Eventually, the lack of coolant will cause your car to overheat – which may in turn precipitate damage to various engine bay components. That`s why it`s a good idea to stop and inspect the issue as soon as you notice it.
A leaky or blown head gasket is often what causes coolant to leak internally. Forming a seal around the combustion chamber, a head gasket is critical to preventing engine coolant and oil from contaminating that chamber and causing serious, costly damage to your engine.
Slow Coolant leaks are extremely difficult to diagnose. Unlike leaking oil, slow coolant leaks leave barely any residue behind. Coolant is half water and it`s other ingredients that don`t form a sticky residue so the slow leaks usually don`t leave an evidence trail.
How much coolant loss is normal? Providing that the engine is running well, with no leakages or damage, you can expect a coolant loss of 0.25% every four to six months. This means a loss of two to three ounces a year is completely normal.
Causes of Coolant Loss

External leaks from radiator hoses, connections between hoses, or from the radiator itself. Radiator cap leaks due to a faulty seal on the cap where the pressurized coolant can leak out. Internal leaks where coolant may leak out of places such as the engine`s head gasket.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I have a coolant leak. I’m not sure exactly where. I noticed a small puddle in my driveway and it leaks out intirely in days.
ANSWER : Coolant leaks can come from a number of components. The water pump, an external head gasket leak, radiator or hose can be just a few locations for coolant to leak from. The best way to locate a coolant leak would be to pressure test the system. The cooling system relies on coolant added to water and pressure to keep the water from boiling over. Pressure testing the system will force the coolant out, enabling the technician to locate the source.

Car leaks coolant when left overnight
ANSWER : Hi there. In some instances, after a radiator is replaced, a coolant line can be left loose by accident or can come loose as the hose clamp gets hot. If the car is parked on a slight uphill slope, the radiator coolant might be leaking from one of the top cooling lines or from the radiator overflow reservoir hose.

The best way to know exactly where your vehicle is leaking coolant from is to have a local mechanic, such as one from YourMechanic, come to your location to complete an inspection to determine the source of the leak.

No coolant in the reservoir. Seen low coolant message. I added 2 quarts of 50/50 coolant. Still getting the message. How much coolant doe it need?
ANSWER : Hi there. For the coolant light to go out, you would need to have the coolant between the low line and the full line for the light to go out. If the coolant is low and keeps on being low, then look for any signs of coolant leaks. You may have to use a coolant pressure tester to pressurize the reservoir to allow the leak to be found.

If you need further assistance with the coolant being low and the warning light being on, then seek out a professional, such as one from Your Mechanic, to help you.

I have a severe engine coolant leak
ANSWER : Hello, the overheating issue needs to be fix as soon as possible, the vehicle should not be operated or you can damage the engine. An overall inspection of coolant system components needs to be done. Some visuals may have to be done underneath the vehicle. Any sealants I would not recommend adding to system. There is a test that can be done to locate leaks. The use of a special tool will pressurize the coolant system safely without the engine operating, by performing this you are able to locate the leak. If you’d like, a certified YourMechanic technician can come to your location to inspect for the coolant leak, and diagnose the overheating issue.

Coolant leaking from top of coolant tank
ANSWER : You either did not get the coolant cap tightened completely when you topped it off before or you have a defective cap. Replace the cap and refill the system while making sure the cap is on all the way. If the problem persists and you suspect something is wrong, then have a certified mechanic, like one from YourMechanic, diagnose the coolant leak firsthand for you. Good luck.

Leaking coolant and coolant jug has to be filled every other day
ANSWER : There are more than five different coolant hoses on your Mitsubishi Montero that may be causing the coolant leak. Without being there to physically inspect the vehicle, it’s hard to diagnose precisely which one is causing the leak. The fact that you’re refilling the reservoir every other day is alarming and should inspire you to have a local mechanic diagnose the source of the coolant leak before it creates a serious overheating situation.

My car has a coolant leak
ANSWER : Hello. The most common cause of a random coolant loss on this vehicle is a leaking intake manifold gasket. It commonly starts leaking coolant into the engine, which will be burnt off or will leak externally. I typically do a pressure test and a dye test on the system first to see if I can locate an external leak. If nothing is found, then I do a block test to make sure that there is not a head gasket issue. If nothing shows up there, then I replace the intake gaskets. If you need to have this done, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the coolant leak and replace the intake gaskets if necessary.

My car has a coolant leak – 2001 Lincoln Town Car
ANSWER : The heater AC (air conditioning) case has a drain to let out condensation from the case. The heater core is positioned in the case that allows it get out through the case drain on the outside of the engine firewall between the center toward the passenger side of the car in the case of a leak. Bypassing the heater core has stopped the leak but the heater and defroster is not inoperative along with the automatic temperature control of the air conditioner. I recommend having the heater core inspected and replaced to fix the system.