---
title: Oil Spots Under the Car: Which Fluid and How Bad
url: https://xpressoilandlube.com/problems/oil-spots-under-car/
business: Xpress Oil & Lube (Xpress Oil & Lube Center)
shops: Reno Northwest: 6100 Mae Anne Ave, Reno, NV 89523, (775) 787-1000, Mon-Fri 8 am-5 pm, Sat 8 am-4 pm, Sun closed; Reno South: 4993 Longley Ln, Reno, NV 89502, (775) 828-6996, Mon-Fri 8 am-5 pm, Sat 8 am-3 pm, Sun closed; Carson City: 1861 E College Pkwy, Carson City, NV 89706, (775) 883-5823, Mon-Fri 8 am-5 pm, Sat 8 am-4 pm, Sun closed; Gardnerville: 1293 US Hwy 395 N, Gardnerville, NV 89410, (775) 301-5912, Mon-Fri 9 am-5 pm, Sat 9 am-3 pm, Sun closed
type: Drive-in oil change and vehicle maintenance, no appointment needed, since 1983
---

Today's coupons

- $10 off full-service oil change
- $5 off smog check
- $25 off transmission fluid service

[See all coupons](https://xpressoilandlube.com/coupons/)

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- [Problems](https://xpressoilandlube.com/problems/)
- Oil spots under the car

# There are spots under my car. What is leaking?

Dark brown or black spots under the front of the car are engine oil, and the usual sources are the drain plug, the oil filter and the pan gasket. Red or pink is transmission or power steering fluid, bright green, orange or pink and watery is coolant, and clear water under the passenger side in summer is the A/C drain doing its job.

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This week

General guidance for this symptom. A warning light that is flashing or an overheating engine: stop driving and call.

## Likely causes

- Drain plug or crush washer The plug comes out at every oil change. A washer reused one time too many, or a plug that was not torqued, seeps a drop at a time. It is the first thing we look at, and the fix is a new washer and the correct torque during an oil change. [Full-service oil change](https://xpressoilandlube.com/services/oil-change/)
- Oil filter seal A filter installed with a dry gasket, or with the old gasket still stuck to the block under it, leaks from the first mile. It can also be a filter that was cross-threaded. Any of those we correct on the spot. [Full-service oil change](https://xpressoilandlube.com/services/oil-change/)
- Oil pan gasket or rear main seal Both are age and heat. A pan gasket leaks along the seam where the pan meets the block; a rear main seal drips between the engine and the transmission and is a big job because the transmission has to come out. We confirm the source and leave the repair to a repair shop. [Multi-point maintenance check](https://xpressoilandlube.com/services/maintenance-check/)
- Transmission or differential seal Red fluid toward the middle of the car is automatic transmission fluid; thick, dark gear oil at the rear axle of a truck is the differential. We top off and service both fluids, and a differential cover gasket is sometimes resealed as part of a differential service, but axle seals and transmission pans go to a repair shop. [Differential service](https://xpressoilandlube.com/services/differential-service/)
- Coolant hose or radiator Sweet-smelling, slightly slimy, bright-colored fluid is coolant. A hose clamp or a cracked plastic radiator tank are the common sources. Coolant leaks are the ones that strand people on I-580 in July, so we move them to the top of the list. [Coolant flush and cooling system service](https://xpressoilandlube.com/services/coolant-flush/)

A driveway tells the truth about a car. Slide a flattened cardboard box under the engine overnight and in the morning you have a map: where the drip is, what color, how much. That one habit turns a vague worry into something we can act on in the bay. Most of what lands on the cardboard is engine oil from a part we touch at every service, which is good news, because those are the leaks we can fix in the time it takes to do an oil change. The others we can identify and send to the right place.

## Read the puddle

Brake fluid gets its own line because it is the one we will not touch and the one you should not drive on. If the pedal feels soft and the puddle is near a wheel, that is a repair shop today, not a quick lube visit.

| Color and feel | Likely fluid | Where under the car |
|---|---|---|
| Brown to black, slick | Engine oil | Front, under the engine |
| Red or pink, thin | Transmission or power steering fluid | Middle or under the front wheels |
| Green, orange or pink, sweet smell | Coolant | Front, near the radiator |
| Clear, odorless | A/C condensation | Passenger side, summer only, harmless |
| Thick, dark, strong smell | Gear oil | Rear axle on trucks and 4WDs |
| Clear to amber, oily | Brake fluid | Near a wheel, stop driving and call a repair shop |

## What we do with an oil leak

On the lift we trace the oil from the lowest wet point back up to the highest, because gravity pulls a leak away from its source. If it starts at the plug or the filter, we fix it during a [full-service oil change](https://xpressoilandlube.com/services/oil-change/): new crush washer, filter seated on a wet gasket with the old gasket removed, correct torque, level set to the full mark. We also wipe the area clean so you can check the cardboard again in a week and see whether it stayed dry.

If the oil starts at the pan rail, the timing cover or the back of the engine, we tell you where and how fast it is coming. A few drops a week on a 150,000-mile Tacoma is something many owners live with and top off. A steady drip is a repair-shop appointment. Either way the decision is yours and the invoice says what we saw.

## Leaks and the high desert

Rubber seals do not love Northern Nevada. Reno gets about 122 nights a year at or below freezing and 65 days at 90 F or hotter (NOAA 1991-2020 normals), so a gasket goes through a 60-degree swing most days of the year. Minden is harsher still at 188 freezing nights. The constant expansion and contraction is why pan gaskets and valve covers that would last the life of a car on the coast start seeping here around the ten-year mark. A high-mileage oil with seal conditioners can slow a seep, which is why we offer it; it does not replace a gasket.

## Before you drive in

- Note where the spot sits relative to the wheels and the engine
- Note the color against white paper
- Check the dipstick so you know how much has left
- If the spot is coolant and the temperature gauge has moved, do not drive it; call for a tow
- Bring the cardboard if you can, it saves us guessing

### Sources

- [carcare.org/car-care-guide/](https://www.carcare.org/car-care-guide/) (Car Care Council: check for leaks and fluid levels monthly; read 10/15/26)
- [ncei.noaa.gov/products/land-based-station/us-climate-normals](https://www.ncei.noaa.gov/products/land-based-station/us-climate-normals) (NOAA 1991-2020 normals: Reno airport 121.9 freezing nights and 65.1 days at or above 90 F; Minden 188.5 freezing nights; read 10/15/26)

### Your service center: Reno Northwest

- Call [(775) 787-1000](tel:+17757871000) Mon-Fri 8 am-5 pm, Sat 8 am-4 pm, Sun closed
- Address 6100 Mae Anne Ave, Reno, NV 89523

[Directions](https://www.google.com/maps/dir/?api=1&destination=6100+Mae+Anne+Ave%2C+Reno%2C+NV+89523&destination_place_id=ChIJ3dFA7yBEmYARYg1CtQTi_Bk)

### Related

- [Burning oil smell](https://xpressoilandlube.com/problems/burning-oil-smell/)
- [Sweet coolant smell](https://xpressoilandlube.com/problems/sweet-coolant-smell/)
- [Low oil between changes](https://xpressoilandlube.com/problems/low-oil-between-changes/)
- [Differential service](https://xpressoilandlube.com/services/differential-service/)
- [The oil filter, explained](https://xpressoilandlube.com/guides/oil-filter-explained/)

Drive in. No appointment. Drive out.

Locally owned in Northern Nevada since 1983. No appointment, no pressure: we tell you what the inspection found and you decide.

[About us](https://xpressoilandlube.com/about/)

## What we do about it

[### Full-service oil change Learn more](https://xpressoilandlube.com/services/oil-change/)[### Multi-point maintenance check Learn more](https://xpressoilandlube.com/services/maintenance-check/)[### Differential service Learn more](https://xpressoilandlube.com/services/differential-service/)[### Coolant flush and cooling system service Learn more](https://xpressoilandlube.com/services/coolant-flush/)[### Transmission fluid service Learn more](https://xpressoilandlube.com/services/transmission-fluid-service/)

## Questions people ask

Still have a question? Call your service center or drive in; there is no appointment to make.

### Is a small oil drip an emergency?

No. Keep the level between the marks and get it looked at this week. A drip becomes an emergency only if it is big enough to drop the level before you notice, which is why the dipstick check matters.

### Can you fix a leaking oil pan gasket?

No, that is a repair shop job. We find it, show you, and fix the plug and filter leaks that are ours to fix.

### My car only leaks after an oil change somewhere else. Why?

Usually a filter gasket or a drain plug washer. Bring it to any of our four service centers and we will check both and set them right as part of a service.

### Does the leak affect my Nevada smog check?

Not directly. The emissions test does not look at oil leaks. Oil dripping onto a hot exhaust can smoke, which does not fail the test either, but it is still worth fixing.