Dangers of a Rear Main Seal Leak?

rear main seal leakHaving any leak in your car can not just get annoying, but start to make your car seem unreliable.  Constantly having to pop the hood to check your fluid levels can making driving seem like a chore and your vehicle like a ticking time bomb.  This can feel especially true if your car or truck has a rear main seal leak.

Any leak your vehicle may have can be a problem.  First of all, a leak can start to make a mess of your engine bay, the underside of your car, and any other components that may be near the leak.  Oil leaks can be especially messy and problematic as the dripping oil will dry to a thick sludge and attract all sorts of road dirt, grime and gunk.  On the underside of your engine and your car’s frame this will make a mess that can be hard to clean.  On your suspension components this can gum up parts that are supposed to move and even accelerate wear on bushings and ball joints.  Your oil leak can also cover electrical connections, and engine accessories like your alternator or air conditioning compressor causing other problems and increasing the difficulty of maintenance items.

The other danger of an oil leak, including a rear main seal leak, is the danger of lowering your oil level to a place where it will no longer properly lubricate your engine which can cause damage quickly.  On most engines, there is a high and low mark on the dipstick indicating an oil level range where it is safe to operate your vehicle.  This range is usually about one quart of oil.  Depending on how fast your leak is and how much you drive, your engine can lose a quart of oil in a very short time.  If your run your engine for long with a low oil level you can quickly damage your main bearings or piston rings due to a lack of lubrication without any warning lights coming on, or the oil pressure gauge indicating a problem.  If your engine oil level gets so low that it is below your oil pump it can starve your entire engine of oil which can quickly damage your valves and camshafts.

Rear main seal leaks often have the potential of lowering your oil level faster than any other leak.  Your rear main seal is at the back of your engine and is right behind the last main bearing.  In this area of the engine, there is high oil pressure that is flowing through your bearings but also oil splashing due to the motion of your crankshaft.  All this means lots of oil has the opportunity to leak out of your engine at this point and the amount of oil leaking will increase with engine RPM.

To make sure your engine stays safe from gunk and grime, but also from a damaging lack of lubrication, make sure to seal any oil leaks you have in your engine quickly.  Often times a rear main seal leak can be easy to let go because the cost of fixing the problem can seem much worse than the risk of running low on oil.  The reality is there may be another alternative!  BlueDevil Rear Main Sealer can repair your rear main seal stopping your leak and saving you from an expensive repair bill now, and engine damage later.

For more information about BlueDevil Rear Main Sealer, click here:
BlueDevil Rear Main Sealer

You can purchase BlueDevil Rear Main Sealer at any of our partnering local auto parts stores like:

  • AutoZone
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributer
  • DYK Automotive


Pictures Provided By:

oil_leak.jpg – By Dawid Zagarski – Licensed by Thinkstock Photos – Original Link

18 responses to “Dangers of a Rear Main Seal Leak?

  1. Hie I have a toyota hiace panel van and need to use your product but 1st- I’m not sure if it’s going to work on my vehicle 2nd- How can I get t in zimbabwe

    1. Patrick-

      BlueDevil Rear Main Sealer has a success rate that is slightly above 90% overall. As long as you are not losing a lot of oil quickly then there is a very good chance that BlueDevil will work to seal it. Once BlueDevil Rear Main Sealer has been added you can expect to start seeing results after about 100 miles of driving.

      We currently do not have any distributors in Zimbabwe but the product can be purchased directly through our website and shipped overseas to you. The order may be placed here: http://store.gobdp.com/rear-main-sealer-00234/

      Thank you!


        1. Darren-

          The BlueDevil Rear Main Sealer does not harden or thicken in anyway, so it would not causes any adverse affects on the engine or the system itself. You can leave the product in the oil for the life of the oil, so you do not need to change the oil immediately after results are achieved.

          Thank you!


  2. Hi Jim here from Ireland Opel corsa start leaking today went to mechanic he told me back crank shaft seal gone would you’re sealer do the trick

    1. Steve-

      Unfortunately, we do not currently have any distributors in New Zealand, however, you are able to purchase products directly on our website, gobdp.com.

      Thank you!


  3. Hi, I recently fixed my car’s slipping clutch and fly wheel. A week later oil from the main rear seal starts leaking I took it to the guys who did the clutch job, they refuse to take responsibility instead they charging a huge amount to fix the main rear seal. I want to know what if the clutch repair can potentially damage the rear main seal. And what else can damage it?

    1. Number-

      It would be unusual if replacing the slipping clutch and fly wheel had an effect on the rear main seal starting to leak. Depending on the make/age/mileage of the vehicle, it wouldn’t be uncommon for a rear main seal leak to develop, especially in older vehicles. Based on your description, we recommend using the BlueDevil Rear Main Sealer (http://store.gobdp.com/rear-main-sealer-00234/). You should expect to see results after about 100-200 miles of driving.

      Thank you!


    1. Lisa-

      Thank you for asking about your Audi A3. No, using the BlueDevil Rear Main Sealer would not cause you to lose more oil or make the leak larger. How quickly are you losing oil? About how many miles have you driven since adding the product? It may be that you are losing the product now along with your engine oil, giving the impression of a larger leak. Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to assist you further.

      Thank you!


  4. I have problem with rear main seal in my audi a4 2010,can i add the product to this car,the oil i put in is 0w40 fuel syntetic. Thanks

    1. Byron-

      Yes, BlueDevil Rear Main Sealer is safe and compatible to use in your Audi. Once added you can expect to start seeing results after approximately 100 miles of driving.

      Thank you!


  5. Do you have to add blue devil with each oil change after it is stopped leaking like lucas or is it a permanent thing?

    1. Keith-

      Once BlueDevil seals the leak, it would be a permanent seal. It is not the kind of thing you would have to add with every oil change. You should only need to use the product once.

      Thank you!


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