Having your car leak oil after an oil change can be frustrating and concerning. An oil leak indicates there is an issue that needs to be addressed promptly to prevent further problems. This article will provide an in-depth look at the common causes of oil leaks after an oil change and the steps you can take to diagnose and repair the issue.
Table of Contents
- Understanding Why Oil Leaks Happen
- Diagnosing the Source of the Leak
- Common Causes Behind Oil Leaks after an Oil Change
- Next Steps to Stop the Oil Leak
- Preventing Oil Leaks After Future Oil Changes
- 1. Choose a Reputable Shop with Certified Techs
- 2. Provide Key Info About Your Vehicle
- 3. Ask Questions About Their Oil Change Process
- 4. Request New Drain Plugs and Washers
- 5. Specify Your Preferred Oil Filter Brand
- 6. Watch the Oil Fill Level Closely
- 7. Inspect the Underside After Each Oil Change
- 8. Retorque the Filter and Drain Plug Areas
- 9. Check for Leaks More Often as Mileage Increases
- When to Take Further Action on an Oil Leak
Understanding Why Oil Leaks Happen
Before jumping into the specific causes, it’s helpful to understand the basics of how oil leaks can occur in the first place. There are a few key ways oil can escape from your engine after an oil change service:
- Improperly tightened drain plug or oil filter
- Damage to oil seals or gaskets
- An overfilled oil level
- Loose fittings, cracked hoses or a compromised oil pan
Small seeps may gradually develop in older engines as seals harden or shrink. But a sudden, noticeable oil leak right after an oil change likely points to an error during the service.
Diagnosing the Source of the Leak
The first step is to accurately diagnose where the leak is coming from. Here are tips on how to pinpoint the source:
1. Look for visible oil drips under the car
Carefully inspect the ground underneath where you park for fresh oil drips or stains. Drips directly under the engine bay typically indicate a loose drain plug or filter. Front or rear leaks point to a leaking seal or gasket.
2. Clean the engine and run it to look for leak points
Wipe off all oil residue and thoroughly clean the engine compartment. Then run the engine for a short time and recheck for any new oil seepage. The fresh drips will lead you to the leak location.
3. Consider the oil change service that was performed
Think about what was done during the recent oil change. Was the filter replaced? Was the oil level reset? Understanding the service tasks can provide clues on where mistakes may have occurred.
4. Have a mechanic inspect if the source is unclear
If you’re still unsure where the leak is coming from, have a certified mechanic put the car on a lift and inspect the underside and engine. They can pinpoint the exact spot and cause.
Common Causes Behind Oil Leaks after an Oil Change
Once you’ve zeroed in on the leak location, you can narrow down the likely causes. Here are some of the most common sources of oil leaks after an oil service:
1. Loose or Damaged Drain Plug
The drain plug at the bottom of the oil pan is designed to provide a tight seal after removing the old oil for an oil change. If this plug is not replaced and tightened properly to the correct torque specs, it can leak steadily. The drain plug can also become damaged if overtightened or crossed threaded.
2. Faulty Oil Filter Seal
When screwing on a new oil filter, it needs to be tightened just right to form a perfect seal. Over tightening can damage the filter gasket. Not tightening enough can leave gaps for oil to escape. Defective oil filters with poor gasket designs can also leak at the filter mounting point.
3. Worn or Damaged Oil Seals and Gaskets
The various gaskets and seals in the engine are meant to contain oil pressure. As engines accumulate mileage, this rubberized sealing components wear out and begin to leak. If an oil change service disturbed an already worn seal or gasket, it may start leaking apparent afterwards.
4. Overfilled Oil Level
Adding too much oil during an oil change can cause excess pressure and volume in the crankcase. This additional fluid has to go somewhere, so it can end up leaking past aged seals. Always double check the dipstick reading before driving away from an oil service.
5. Loose Oil Pan Bolts
The bolts holding the oil pan in place can vibrate loose over time. If these were already loose before an oil change, the process of draining and refilling fluids could cause them to finally leak. It’s wise to check oil pan bolts for tightness with each oil service.
6. Damaged or Dislodged Oil Sending Unit
Many engines have an oil pressure sending unit located somewhere in the block. If this sensor gets accidentally knocked during an oil change, it can dislodge and leak. Any damage to the sending unit seal will also cause oil to escape.
7. Aftermarket Oil Filter Adapter Failure
Some vehicles use a special adapter housing where the oil filter screws in. Low quality aftermarket versions can become compromised and leak at this junction point, especially if the filter is overtightened.
Next Steps to Stop the Oil Leak
Once you’ve diagnosed the exact oil leak location and likely cause, you can take action to correct it:
- Tighten any loose fittings – this may include the drain plug, oil filter, oil pan bolts or other fasteners that need to be properly torqued down. Always use a torque wrench for accuracy.
- Replace damaged gaskets and seals – worn or blown seals and gaskets will need to be replaced to permanently stop stubborn oil leaks after an oil change.
- Add sealant compounds – sealers like Hylomar or Hondabond can be applied to help stop minor oil leaks from worn areas.
- Adjust overfilled oil level – carefully drain excess oil using a suction device if the crankcase was overfilled during the oil service.
- Have additional repairs made – more involved issues like a damaged oil pan, cracked sensor or adapter housing will require proper repairs.
- Ask the oil change shop to inspect repairs – if the leak points to a mistake during service, request the shop inspect the repair and rectify any errors.
- Retorque key areas after initial repairs – recheck drain plugs, filters and other tightened areas after a short drive to ensure no further leakage.
With the right diagnosis and targeted repairs, you can get those annoying oil leaks sealed up quickly. Pay close attention in the days and weeks after repairs to ensure no new leaks develop. Catching and repairing oil leaks promptly is crucial to avoid extensive engine damage down the road.
Preventing Oil Leaks After Future Oil Changes
Once you’ve taken care of the current oil leak, it’s wise to take proactive steps to prevent leaks after future oil changes:
1. Choose a Reputable Shop with Certified Techs
Go to a shop with ASE certified technicians and a solid reputation for doing the job right the first time. Quick lube chains with unskilled staff often make mistakes leading to leaks.
2. Provide Key Info About Your Vehicle
Inform technicians about any existing oil leaks, strange engine noises or issues needing repair. This allows them to inspect these areas and prevent exacerbating existing problems.
3. Ask Questions About Their Oil Change Process
Get details on the oil service: do they hand torque or use impact tools on drain plugs and filters? Are proper torque specs and sequences followed? Do they inspect all seals and gaskets? Understanding their process helps ensure no steps are missed.
4. Request New Drain Plugs and Washers
Ask for brand new drain plugs and sealing washers each oil change to get a perfect leak-free seal after the old oil is drained.
5. Specify Your Preferred Oil Filter Brand
Stick with a quality oil filter brand you know seals well for your engine. Avoid cheap generic filters that may leak.
6. Watch the Oil Fill Level Closely
Check the dipstick reading before driving off to ensure the tech did not overfill the oil level, leading to leaks past seals from too much volume or pressure.
7. Inspect the Underside After Each Oil Change
Make a habit of examining under your vehicle after every oil service for any small leaks developing. Address them immediately before major leaks occur.
8. Retorque the Filter and Drain Plug Areas
Consider retorqueing the oil filter and drain plugs to spec yourself as an added precaution against loose fittings.
9. Check for Leaks More Often as Mileage Increases
As engines accumulate miles, inspect for oil leaks more frequently between changes. Repair minor seepage issues promptly before it becomes a bigger problem.
When to Take Further Action on an Oil Leak
Minor seepage from very old engines may not require immediate repair. But significant leaks should always be addressed right away. Here are signs a leak is severe enough to require urgent action:
- Steady dripping that leaves puddles of oil
- Low oil pressure warning or engine noises from low oil
- Oil spots expanding quickly over concrete
- Oil spraying violently from a suddenly detached hose or gasket
If you notice these warning signs, have the car towed to prevent driving it until repairs can be made. Letting major oil leaks go unattended risks damaging internal engine components through inadequate lubrication.
While a car leaking oil after an oil change is frustrating, the good news is the problem is usually limited to a handful of common issues. With methodical diagnosis and targeted repairs, you can stop the leak, prevent future recurrence, and avoid expensive damage from oil starvation. If the leak points to a mistake during service, insist the shop make it right at no charge. And consider switching garages if problems persist. With close inspection and care after oil changes, your car can get back to leak-free operation.