How to Troubleshoot Engine Coolant

Your car's engine may have a leak in its coolant system if it suddenly starts using greater amounts of coolant than usual. Diagnosing an engine coolant leak can be tricky because leaks aren't always visible. A full reservoir of coolant usually lasts about a year, so if your vehicle starts going through its coolant in a week or even a day, you have a leak. Before you take your car to a dealership to have it checked, try to determine the source of the leak. Do not attempt to fix a coolant leak unless you have mechanical experience.

Instructions

1

Look under your car after it has been parked for a few hours to see if there is a puddle of coolant on the ground underneath the engine. Coolant is generally green, yellow or red in color. If a leak is external, it may spill out of your car's coolant system and onto the pavement. You might need to back up your car to check the ground completely. A leak of this nature could also present itself as a trail of liquid that follows your car's path. Look behind your car immediately after parking to see if there is any coolant on the ground.

2

Open your car's hood and look inside the engine compartment for visible leaks. Look at the hoses and belts leading away from your coolant reservoir and toward your engine. Check for cracks or holes that indicate that these parts need to be replaced. You might be able to see an external leak if your coolant is escaping through a visible part of your coolant system.

3

Put coolant into your reservoir in your engine compartment and examine the reservoir for leaks. If there is a crack or hole in the reservoir, you will see coolant begin to seep out. This is an external coolant leak. You can purchase a new reservoir from a dealership's parts department that sells parts for your car's make or from auto supply stores. If you choose to install it yourself, follow the instructions carefully to avoid damaging your engine.

4

Pull out your oil dipstick and examine your oil for coolant content, which will be noticeable because it is typically bright in color, while oil is brown. You will see the color of your coolant mixed in with your oil. If there is coolant in your oil compartment, you have an internal leak in which the coolant is leaking into the oil. Take your car to a mechanic to have him open your engine block to find the problem.

5

Examine your car's exhaust pipe after you start your engine and let it idle in park or neutral gear for a few moments. If you see smoke coming out of your pipe, your coolant might be leaking into your exhaust system and exiting through the pipe. A mechanic may inject dye into your exhaust system to determine the location of the leak; the dye will seep out from the leak and is easier to see than the coolant.

6

Take your car to a dealership for service or to a mechanic. She will be able to determine the source of your leak. If you can't see a leak, it may be internal. She will tell you whether your water pump or intake manifold gasket is leaking or if there is a problem with another part. Dealers sometimes charge fees to diagnose your car. Be prepared to pay for an expensive diagnostic evaluation and mechanical repairs.