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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Jonathan

26 years of experience
54 reviews
Jonathan
26 years of experience
Honda Ridgeline V6-3.5L - Oil/Fluid Leak - Roswell, Georgia
Johnathan was courteous and professional. He took his time to go over my vehicle and give me all of the details for the issues at hand.
Hyundai Elantra - Oil/Fluid Leak - Marietta, Georgia
He was great. Arrived early for appointment and diagnosed issue and gave recommendations. He followed covid protocols without me having to ask. Will hire him for additional jobs and highly recommend his honesty and explanations of issues.

Nolan

30 years of experience
126 reviews
Nolan
30 years of experience
Chevrolet Captiva Sport L4-2.4L - Oil/Fluid Leak - Tucson, Arizona
I've had some bad EXPERIENCE with mechanics BUT NOLAN EXPLAINED EVERYTHING AND WENT OUT OF HIS WAY ,AND SO FRIENDLY AND POLITE AND HE LISTENED TO MY CONCERNS

Joseph

20 years of experience
571 reviews
Joseph
20 years of experience
Nissan Frontier V6-3.3L - Oil/Fluid Leak Inspection - Salt Lake City, Utah
This was the second visit from Joseph. He quickly diagnosed my oil leak and showed me the source. He also went around and checked the pressure in all of the tires. In addition to scheduling the necessary repair, he also gave me pointers for maintaining my truck since I have not driven it much during Covid. He is great to work with and I will be using him for ALL of my truck maintenance and repairs.

Chris

22 years of experience
2068 reviews
Chris
22 years of experience
Volkswagen Jetta L4-1.8L Turbo - Oil/Fluid Leak - Trabuco Canyon, California
Chris is ALWAYS on time, professional and a pleasure to work with: he explains everything well and keeps his customers aware of what’s needed to keep our cars in top running condition! Thanks, Chris, for your phenomenal service!

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