Oh man, are you in trouble. Your car or truck is leaking oil, and that can be a really bad sign. Left unchecked, it can destroy the vehicle’s engine, cost you thousands of dollars and leave you without transportation. Even in the best case scenario, you’re pouring new oil—and money—down the crank case periodically, and either drizzling oil on the road and in your driveway or blowing it out your exhaust pipe. Either way, you’re not being very kind to the environment.
Bottom line: You need to do something about the oil leak in your car or truck.
Stopping an oil leak ranges from simple to complicated and from a couple of bucks to $1,000. Before repairing the leak it is important to understand motor oil’s critical purpose in the engine and the various sources of an oil leak.
How Oil Works in a Car
Oil is a lubricant, specifically formulated to withstand a temperature range from below zero to above 200 degrees Fahrenheit while cycling through a vehicle’s engine. Motor oil is fed into the engine’s mechanical parts to protect metal parts that move constantly, like pistons that pump up and down rapidly inside metal cylinders. Oil forms a barrier between the metal piston and the metal cylinder to prevent wear, ensure smooth motion and keep metal from burning up.
As it circulates around the combustion chamber towards the oil filter for its regular cleaning, oil offers a helping hand to the antifreeze-water combination working hard to cool the parts of the engine that are literally on fire. Oil circulates many thousands of times during its 3,000 miles or more of life inside the vehicle.
Oil does not work as well when it is draining out of the system via a hole, crack or bad fitting seal. Even worse, when oil seeps into the combustion chamber, where fire needs to ignite fuel and air to power the vehicle, the presence of oil can interfere with the process. Oil on a spark plug can prevent sparking. Oil in the coolant can reduce its cooling capacity and clog up the system.
In other words, oil is critically important where it is needed and a terrible disrupter where it doesn’t belong.
What Causes an Oil Leak in a Car and How Do I Stop It?
There are a handful of reasons oil is leaking either under the hood or outside the vehicle. Here are some of the common causes of an oil leak and how to fix each one:
1. The oil filter was installed incorrectly.
The best-case scenario in the world of oil leaks is that the oil filter was improperly attached. Either it was screwed on too tight, which can mash the top of the filter and prevent a good fit, or it was not tightened sufficiently. Oil filters sometimes screw on a little off-kilter and fail to make a tight seal. Any of these can cause a leak.
The fix:Oil filter leaksare easily repaired by loosening or tightening the filter, or re-attaching it. If it is being removed, the oil must first be drained or you could end up wearing several quarts of motor oil and adding a new shirt to the cost of the repair.
Remember that an oil filter is loosened with a filter wrench but tightened only by hand. Using a wrench will cause over-tightening and risk a new leak.
A common mistake made by DIYers involves the oil filter gasket. After 3,000 or more miles that prompt an oil change, the gasket can get stuck to the engine even as the filter is removed. Attaching a new oil filter, with its own gasket (or o-ring) on top of the original gasket, prevents the filter from fitting tightly and creates an avenue of escape for oil.
The fix:The good news about this issue is that it is simple to repair. Drain the oil, as you would do for an oil change, recapturing it in a drain pan, and correct the filter issue. Then pour the oil back into the crank case and add however much is needed.
2. The drain plug was tightened wrong.
This is another good case scenario. The drain pan and plug hang beneath the vehicle and invite attacks by roadway debris like rocks, gravel, dirt and whatever can fall off the back of a truck. Eventually, the wear and tear can punch a hole in the plug or pan, corrode them or otherwise reduce their structural integrity.
The fix:This is an easy problem to spot and fix, simply by replacing the plug or pan. A new drain plug is a couple of bucks and a whole new pan varies but generally costs below triple digits.
The plug can also be over- or under-tightened. The latter is a simple matter of tightening it further. Putting too much torque on the plug can break it or the nipple onto which it attaches. Again, that might mean a new plug or drain pan. As with the oil filter, removing the pan requires first draining the oil.
3. There is a problem with a gasket, seal or o-ring.
This is a broad category of problems that have the following in common: a transition point in the engine where two parts meet and are sealed by a gasket, o-ring or valve seal is not airtight. There are many such points in an automobile, such as the rocker cover gasket, the front-end timing cover gasket, the front main seal, the head gasket, the dipstick tube o-ring and more.
With most of these seal leaks, oil will spill and build up on engine parts, Left to its own devices, the oil will grease other parts of the engine and interfere with the combustion process. This will present itself, eventually, in lost gas mileage and inefficient operation.
These leaky seals are easy to fix, simply by replacing the gasket, o-ring or valve seal, usually a rubber part costing a few dollars. Unfortunately, some of them are more difficult to access than others and can make repair a costly and time-consuming nightmare.
An example of this is the head gasket, which is actually a more complex metal sandwich that separates the engine block from cylinder head. Its job is specifically to keep oil from spilling into the chamber where explosions occur and to keep fuel and sparks from destroying the moving parts. Though easy to replace, accessing this $20-$50 gasket requires the disassembly of many engine parts and generally costs over $1,000 at a service station.
The fix:If the problem is a small leak in a hose, pan or seal, an easy, inexpensive and permanent solution is a sealent, like BlueDevil Oil Stop Leak. Poured into the crank case, a $20 bottle of BlueDevil Oil Stop Leak fills the crevices and keeps the oil where it belongs for the life of the car, guaranteed. When using this product, the engine must be allowed to run for an hour or two so the solution can circulate completely through the vehicle.
For a head gasket issue, try BlueDevil Pour-N-Go Head Gasket Sealer. It offers an inexpensive and permanent solution to a very costly head gasket repair. The directions for use of this product are a little more complicated, so read and follow them carefully.
4. The rear main seal is leaking.
If oil is emanating from the back of the engine, that is a sign of a leaky rear main seal. It is bad news and should be addressed immediately.
The rear main seal keeps oil inside the rear of the engine where the transmission connects to the crankshaft. Because of the oil pressure at that point, even a small leak is liable to grow quickly. Also, the leaking oil tends to collect on the underside of the vehicle, creating a mess that is difficult to clean and risking a fire hazard if the oil gets into the exhaust system. In other words, don’t let a rear main seal leak go for long.
The fix:Accessing the rear main seal requires removal of the transmission—and sometimes other parts of the engine—driving up the cost to the $600-$1,000 range, though the seal itself is merely a rubber or silicone ring priced at a few bucks. Some mechanics won’t consider repairing a rear main seal without removing the motor and at least partially rebuilding the engine.
When the hard repair part isn’t an option, a chemical sealant like BlueDevil Rear Main Sealer is guaranteed to seal the leak permanently in gas or diesel engines. Simply empty a bottle into the engine oil while the vehicle is turned off and start the engine. It could take up to two days of driving for the leaks to seal.
Whatever the source of the oil leak, the best course of action is to repair the leak, either yourself or by bringing the vehicle to a professional mechanic.
6 responses to "How to Stop an Oil Leak in Your Car"
BlueDevil Oil Stop Leak seals engine oil leaks permanently. It is non-clogging and will not harm your engine. BlueDevil is safe and easy to use and is compatible in gasoline or diesel engines. Our stop leak additive solution is guaranteed to keep your leak sealed even after miles of driving or your money back.Does Blue Devil damage your engine? ›
Is Blue Devil Bad for Your Engine? The answer is a resounding no. And if you are wondering about the safety of using other brands of rear main seal conditioners and stop-leak products like Bar's Leak or Justice Brothers, don't worry. They almost all use the same active ingredient.Which is the best additive to stop an oil leak? ›
If you're looking for universal protection, then Lucas Oil 10278 Engine Oil Stop Leak is the best engine oil stop leak product on the market. Customers who want to stop leaks and save money should use ATP AT-205 Re-Seal Stops Leaks.Do oil leak sealers work? ›
The short answer is . . . sort of. While the new formulas will stop those leaks in many situations, they aren't a permanent solution. The leaking seal will, sooner or later, need replacing.What can I use to stop my car from leaking oil? ›
If you're looking for an easy, straightforward fix, you can use a stop leak additive or high mileage oil blend to help seal the leak. While this method is as simple as purchasing the additive and pouring it in, it may take a while (a hundred miles or two) before the leak stops entirely.How long does oil leak sealer last? ›
So how long can you expect them to last? It depends. If the leak is mild to moderate, we've had customers run 10,000-50,000 miles with no further issues. If the leak is more severe, or on the edge of becoming severe, the repair might last a shorter duration.How long does stop oil leak take to work? ›
Drive vehicle normally. Allow up to 200 miles/300 km for Engine Stop Leak to be fully effective.Does Stop leak hurt your car? ›
Many people think that using stop leak products can save money by stopping a transmission fluid leak. Unfortunately after affects of using leakage stopping products come at a significant cost. Stop leak products can cause irreparable damage to your vehicle.Is BlueDevil a permanent fix? ›
The BlueDevil head gasket sealer ensures that your car's vital component, the engine, is permanently fixed in terms of seals and cracks. The sealant flows to a leak point to create a permanent seal, ensuring no fluid loss or risk of an engine misfire.Can you use too much BlueDevil? ›
Adding too much of this is enough to cause blockages in heater matrixs and radiators. Before doing anything to repair a non-existent head gasket leak, have either a compression test or leak down test carried out as this will generally be cheaper than one of these liquid gasket repair fluids. Save this answer.
Are oil additives bad for your engine? Not really, no. People think that they need an oil additive to “improve the lubrication” for their oil. But they don't really need that because today's high-performing oils do that job plenty well.Is there an oil additive that stops leaks? ›
Lucas Engine Oil Stop Leak is a unique formulation of Lucas additives and base stocks designed to stop leaks in engines. It is also an exceptional additive for worn and older engines, reducing engine noise and oil consumption while raising oil pressure.Which oil seal is best? ›
Buna (Nitrile) oil seals are the most widely used elastomer in sealing. Nitrile oil seals have great resistance to petroleum oils and fuels, mineral oils and greases, hydraulic fluids, water, steam, and alcohol.Is leak sealer a permanent fix? ›
It is often suggested by plumbers and even national boiler maintenance companies as a cheap and easy fix. The only thing is, if the sealant does work, it tends to be a temporary fix. It's a bit like a sticking plaster, that will come off in the future and so the leak comes back.Can you drive with a oil seal leak? ›
Driving a car with an oil leak can be dangerous for you and other road users. Oil can become flammable when it reaches a certain temperature and parts of your vehicle's engine can get very hot, which may result in a fire. However, oil can also cause damage to seals and rubber hoses, which could result in a breakdown.Where do you pour Blue Devils? ›
IMPORTANT: POUR SLOWLY! Start the engine while cold, then turn the heater on max. With engine idling, SLOWLY POUR BlueDevil into the radiator. (If the vehicle does not have a radiator cap you may pour BlueDevil in through the top radiator hose. Take 1 minute pour time for entire bottle.)Where do you put BlueDevil? ›
Remove the radiator cap and start the engine while cold, then turn heater to Max. IMPORTANT: POUR SLOWLY! With the engine idling, SLOWLY POUR BlueDevil into the radiator (take 1 minute pour time for entire bottle – 30 seconds for 1/2 bottle).Is BlueDevil good for your car? ›
BlueDevil contains no solid or particulate matter, and will not clog or harm your engine. It bonds to metal, aluminum, cast, alloy, or plastic, and it's safe and easy to use.Does BlueDevil oil Stop rear main seal leak? ›
Description. BlueDevil Rear Main Sealer permanently stops rear main seal leaks. Just add to the engine oil to restore and seal gaskets. BlueDevil Rear Main Sealer is a great repair for timing cover leaks.What happens if you put too much stop leak in your car? ›
Over time what happens is the stop leak product that was put into the cooling system starts to break down, dry up, and break apart, causing debris and potentially even a large clump to go free-falling into the cooling system.
Use 1/2 bottle for four cylinder engines. One bottle treats up to 4 gallons. For larger systems use one bottle for every 3 gallons of coolant capacity. Small engines or other small systems use 3 to 4 fluid ounces per gallon of fluid capacity.Is Stop leak temporary? ›
Radiator Repair. It's important to understand that stop-leak is usually only a temporary solution, or a solution to a minor leak. Why is there a leak in your radiator? Stop leak additives may seal the pinhole leak in your radiator, but they may not deal with the source of the damage.How much does BlueDevil cost? ›
How much does it cost to participate? The exact participation fees vary from year to year, but generally the cost for participating in the Blue Devils* is approximately $3,500. Payment can be made in installments.Can I use 2 bottles of BlueDevil? ›
Q: Can You Use Blue Devil Head Gasket Sealer Twice? Yes. You can use the blue devil head gasket sealer more than once. This product does not contain petroleum distillates, so you might use it more than once if a leak occurs after the last time you used it.Will BlueDevil stop a heater core leak? ›
BlueDevil Pour-N-Go is a quick and easy solution to many cooling system leaks in your car or truck, including a leaking heater core. BlueDevil Pour-N-Go is an easy to use product that you simply add to your engine coolant and will work to seal your leak as you drive.How do you use BlueDevil pour and go stop smoke and engine repair? ›
Turn engine off and add 1/2 bottle (8 oz.) of BlueDevil Stop Smoke & Engine Repair into engine crankcase. Drive vehicle normally. Results will be noticeable after 100 miles of driving.What happens if too much engine oil is added? ›
When too much oil is added, the level in the oil pan becomes too high. That allows a fast-moving lobed rod called the crankshaft to come into contact with the oil and essentially aerate it. The result is a foamy, frothy substance that cannot properly lubricate the engine.How much oil additive should I use? ›
Use. The dosage of Oil Additive should be 3-5% of the oil filling quantity. Oil Additive can be used at any time, even between oil changes.What is the best leak sealant? ›
- Liquid Rubber Waterproof Sealant. ...
- Flex Seal Spray Rubber Sealant Coating. ...
- Dicor Self-Leveling Lap Sealant. ...
- Gorilla Waterproof Patch & Seal Tape. ...
- Liquid Rubber Color Waterproof Sealant.
Generally speaking, gaskets serve as a static seal between flat surfaces, such as joints, while seals are used in more dynamic environments between active components such as rotating shafts, pumps, and engines.
Repairing an oil leak might range from $100 to $2,000 or more. The high rate is due to the many different sources of an oil leak and the location of the leak. Also, the type of car you drive has an important impact on engine oil leak repair costs.How do you seal a leak fast? ›
Use epoxy putty or pipe putty as a temporary fix to a leaky pipe. Pipe putty is designed to harden at room temperature and seal the hole or crack.How long does it take for a leak to stop? ›
It can take a minimum of two weeks but sometimes up to four weeks. Ensure you address the leak's cause to ensure you are solving the problem rather than going in an endless circle. After all, things cannot dry if it is still getting wet!How do you install a leak sealer? ›
- Ensure pipework is clean. ...
- Relieve system pressure if you haven't already done so.
- Apply the product as follows: ...
- Replace the cap immediately to prevent the remaining product from curing inside the tube.
- Spray the sealant with water to aid the curing process.
Repairing an oil leak might range from $100 to $2,000 or more. The high rate is due to the many different sources of an oil leak and the location of the leak. Also, the type of car you drive has an important impact on engine oil leak repair costs.How do you stop an oil leak fast? ›
One of the easiest ways to fix the leak yourself is to use a stop leak additive or high mileage oil blend. Such products can soften and condition your car's rubber seals to stop and prevent further automotive leaks. It may take up to a few hundred miles of driving before the leak is completely sealed.Can I still drive my car if its leaking oil? ›
A: It's always advisable not to drive if your vehicle has an oil leak, but short distance drives, less than 10 miles, are not as risky when it comes to lowering your oil levels to a dangerous point.What causes an oil leak to get worse? ›
The vast majority of leaks are due to degraded engine gaskets, oil pan leaks, oil seals or bad connections. Crawl under the car and check the oil pan seals. While you're there also check the oil pan drain plug. Next check the timing cover seal and the valve cover gaskets.What happens if you drive a car with an oil leak? ›
Driving a car with an oil leak can be dangerous for you and other road users. Oil can become flammable when it reaches a certain temperature and parts of your vehicle's engine can get very hot, which may result in a fire. However, oil can also cause damage to seals and rubber hoses, which could result in a breakdown.