2018 Chevrolet Suburban Is Leaking Oil

Identifying the Causes of Oil Leaks in Your 2018 Chevrolet Suburban and How to Fix Them

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Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
80% chance it's the
Oil System Components
0%
20% chance it's the
Engine Gaskets
The most common reasons a 2018 Chevrolet Suburban is leaking oil are oil system component failure and leaking engine gaskets.
  • Oil System Components: A worn or damaged oil pump or filter can lead to low oil pressure, resulting in inadequate lubrication and potential engine damage.
  • Engine Gaskets: A worn or damaged engine gasket can lead to oil or coolant leaks, resulting in engine overheating or loss of lubrication.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2018 Chevrolet Suburban is leaking oil?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Oil pans don't wear out or break like other parts, they generally only need to be replaced because of external damage from an accident or an improperly tightened drain plug. The main symptom you will experience is an oil leak underneath the engine of your car. The oil that leaks from a damaged oil pan will range from dark brown to dark black. If the leak is large enough or occurs for long enough the oil level will be low enough to turn the oil pressure or low oil level warning light on.

An oil leak may be noted on the ground where the vehicle is parked. However, many vehicles have plastic trays underneath the engine that may catch leaking oil and conceal the leak. In such cases, a low oil level, a burning oil smell, or even smoke from oil burning in the engine bay may be noted.

»MORE: Signs of a bad oil pan gasket

A bad oil level sensor may cause a false reading of the engine oil level. The oil level warning light may illuminate even when the oil level (checked manually) is within an acceptable range. The warning light may also come on and off intermittently if the sensor is faulty. An error code may be sent to the PCM and a check engine light may come on the dashboard as well if the sensor is bad.

The engine oil pressure warning light will come on if the engine oil pressure is low, or if the oil pressure sensor is faulty. In either case, engine power may be reduced significantly. The check engine light may also illuminate, and an on-board diagnostic (OBD) trouble code will be stored in the vehicle's computer.

What steps should I take to diagnose the oil leak in my 2018 Chevrolet Suburban?

When diagnosing an oil leak in your 2018 Chevrolet Suburban, it's essential to adopt a systematic approach that prioritizes simpler checks before moving on to more complex diagnostics. Begin by locating the leak; inspect the area beneath your vehicle for any visible oil spots, which can help you pinpoint the source. Next, examine the oil pan for cracks or damage, as this is a common culprit for leaks. Ensure that the oil filter is securely installed, as a loose or damaged filter can also lead to oil loss. Don’t forget to check the oil drain plug; it should be tight to prevent any leaks from that area. Additionally, inspect the gaskets and seals around the engine, as wear and tear can result in oil seeping out. Regularly monitoring your oil levels is crucial, as a significant drop can indicate a leak that needs immediate attention. If these steps do not reveal the source of the leak, or if the problem persists, consulting a mechanic is advisable for a thorough diagnosis and repair. By following this methodical approach, you can effectively identify and address the oil leak in your vehicle.

What are the common causes of oil leaks in a 2018 Chevrolet Suburban?

When dealing with oil leaks in a 2018 Chevrolet Suburban, it's crucial to understand the common culprits that may be at play. One frequent issue is the deterioration of the oil pan gasket, which can wear out over time and lead to leaks. Similarly, valve cover gaskets are prone to wear and can allow oil to escape from the engine, creating a mess and potentially causing further damage. Another area to inspect is the oil filter housing gasket; if this component fails, it can result in oil leaking around the filter, which is often noticeable during routine checks. Additionally, the rear main seal, located at the back of the engine, can also develop leaks as it ages, leading to significant oil loss if not addressed. Lastly, oil cooler lines are susceptible to wear and tear, which can result in seepage. By being aware of these common issues, DIYers can take proactive steps to inspect and repair oil leaks, ensuring their Suburban remains in optimal condition. Regular maintenance and timely inspections are key to preventing more severe engine problems down the line.

How urgent is it to address the oil leak in my 2018 Chevrolet Suburban?

Addressing an oil leak in your 2018 Chevrolet Suburban is not just a matter of routine maintenance; it is a pressing issue that requires immediate attention. Ignoring an oil leak can lead to a significant drop in oil levels, which compromises the lubrication of essential engine components. This lack of lubrication can result in severe engine damage over time, leading to costly repairs that could have been easily avoided. Furthermore, an oil leak can cause the engine to overheat, as insufficient oil circulation prevents proper cooling, increasing the risk of engine failure. Beyond mechanical issues, there are safety concerns to consider; leaking oil can drip onto hot engine parts, creating a fire hazard that endangers both the vehicle and its occupants. Therefore, it is crucial to address any signs of an oil leak promptly to safeguard your vehicle's performance and ensure your safety on the road.

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Causes of Oil Leaks in 2018 Chevrolet Suburban | RepairPal