How to Quickly and Accurately Find the Source of an Oil Leak

Engine oil leaks are the most common of all automotive fluid leaks. With the number of seals and gaskets located around the engine bay, oil can leak from almost anywhere.

If the leak occurred some time before you notice it, the oil may have spread far from the real source. Air moving through the engine by driving or being pushed through the cooling fan can cause the leaking oil to cover areas far and wide. Also, if it isn’t a large and/or obvious leak, it will take some investigating to locate the source as it may also be caked with dirt and debris.

Part 1 of 2: Use a degreaser

It’s best not to start replacing seals, gaskets, or other components until you locate the exact source of the leak. If the leak is not obvious, the easiest way to start looking for the source is with a cool engine.

Materials Needed

Step 1: Use the degreaser. Spray a little all-purpose degreaser on the area you see oil. Allow it to penetrate for a few minutes and then wipe it off.

Step 2: Check for a leak. Start the engine and let it run for a few minutes. Check to see if you can spot a leak below the car.

If there is no evident leak, then it may be small enough that it may take days of driving to become evident.

Part 2 of 2: Use a U/V leak detector kit

The fastest way to spot a leak is to use a leak detector kit. These kits come with fluorescent dyes that are formulated for specific engine fluids and a UV light. When the oil starts coming out of the source of the leak, the fluorescent dye will leak out with it. Shining the UV light around the engine bay will make the dye glow, usually a fluorescent green that is easy to spot.

Materials Needed

Step 1: Put the dye into the engine. Pour the leak detector dye into the engine.

  • Tip: If your engine is low on oil, add a bottle of the correct dye for engine leaks to the oil you’re adding to the engine, then pour the oil / leak detector mixture into the engine. If the engine oil level is ok, simply pour the dye into the engine.

Step 2: Turn on the engine. Run the engine for 5-10 minutes or even take it for a short ride.

Step 3: Check for oil leaks. Let the engine cool down before you start shining the uv light into tight spaces. If your kit supplies yellow goggles, put them on and start checking around the engine compartment with the uv light. Once you spot the glowing green dye, you’ve found the source of your leak.

Once you identify the source of the oil leak in your car, have it inspected by a certified service professional, such as one from YourMechanic.


Next Step

Schedule Oil/Fluid Leak Inspection

The most popular service booked by readers of this article is Oil/Fluid Leak Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

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Eliud

24 years of experience
312 reviews
Eliud
24 years of experience
Nissan Murano V6-3.5L - Oil/Fluid Leak - Lawrenceville, Georgia
Very helpful and knowledgeable. He answered all my questions and was very willing to help and make recommendations. I'll highly recommend this tech.
Dodge Journey - Oil/Fluid Leak - Loganville, Georgia
I would recommend Eliud to anyone in need of car maintenance. I've used his services on several occasions. He was always on time for every appointment. He is very knowledgeable and always provides excellent service. I highly recommend him!

David

16 years of experience
93 reviews
David
16 years of experience
BMW 325i L6-2.5L - Oil/Fluid Leak - Discovery Bay, California
Example of what a professional mechanic should be for your organization. Knowledge and experience surpass regular mechanics.
Chevrolet Impala - Oil/Fluid Leak - Concord, California
Is very polite, very respectful property, while doing an excellent inspection, he gave me lots and lots of details, I understood him and most of all he listened!!!! After he heard what I had to say, he took it all in, then david took care of it. thank you very much David!!

damian

9 years of experience
16 reviews
damian
9 years of experience
Ford Explorer V6-4.0L - Oil/Fluid Leak - Norwalk, Connecticut
Damien was punctual and did very thorough, professional job. He patiently answered a lot of questions I asked. I would recommend him.

Matthew

26 years of experience
50 reviews
Matthew
26 years of experience
Honda Accord L4-2.2L - Oil/Fluid Leak - Jacksonville, Florida
Matthew was very professional and courteous. He explained my issues and provided helpful information

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