Rear Main Sealer

I have a 2009 F150 with over 337,500 miles on the original engine. It developed a persistent rear main seal leak about a year ago. Having called the local dealer, I was quoted labor only of $1,900 to repair this leak. I went on Amazon to see if there might be anything out there that would help. I purchased this Blue Devil pour and go rear main sealer and had it delivered next day, put it in the crankcase as instructed and drove to Ft. Lauderdale (200+ miles roundtrip) So far, after about 400 miles, it looks to me that the leak has stopped. I'm hopeful that it stays stopped and will no longer be a mess on my paver driveway!! I recommend this product based on this outcome.

We are in the middle of moving 650mi and I noticed on my first of 4 trips, that the oil cooler on my Duramax Diesel was leaking. It was leaving a 8-10" puddle under it every night. After using this my puddle has disappeared and now I get a spot about the size of a quarter. I've put 1500 miles on it and will need to get another 1500 out of it before I will have time to re-seal the oil cooler properly. But this seems to have done the trick for the time being. I Definitely recommend this stuff as a bandaid to get you buy until a proper repair can be made. Just DO NOT use in ANY powertstrokes.

Amazing! 2000's Ford Ranger 4.0 for my 87 yo father that developed a main seal leak and was really smelling bad. Poured it in and within a day or so the oil smell was almost gone. Very happy with results.

I’ve always been leery about the various automotive cure alls, but let me tell you about this product. First off, this was used on a 2007 Chevy Tahoe that has 175,000 miles. Unfortunately, it had a cracked radiator and my daughter didn’t notice that it was getting hot before it threw a overheated code and shut down the engine. Before this, although it had high mileage, it wasn’t leaking water or oil. I brought the car home and replaced the radiator, hoses, and while I was at it the drive belt. Upon start up, it started dripping oil from the rear main. I wasn’t happy at that point. I really didn’t have the time to deal with replacing the seal and knew it would probably cost $1500 to $2000 to have replaced at the shop. At that point, I started thinking about giving a sealer a try. I figured for the under $20 cost, it was worth trying, although I had my doubts. After pouring the product in the engine, we started the engine and allowed it to idle for about 15 minutes. It still had the drip, although I knew it needed longer to react. The car was then driven on a few short 20 mile trips while observing the drips once parked and idling. The drips that began as about one per 20 seconds had been reduced to one every 60 seconds. After about another 100 miles, the leaking stopped. Currently, the Tahoe has had an additional 1000 miles put on it and still no leaks! I am impressed! I don’t know what will happen in the future, but it’s sure working now. I would highly recommend this product to any of my friends or family without any reservations. I’m so happy that I decided to give it a try. Follow up 2 months later…. Still no leaks after 2 months and another 1500 miles. Very happy so far!

Do not buy this if you have 3.5 Honda engine or possibly any engine with VCM. Ran this for my wife’s 2008 Pilot for one day and it clogged the VCM module causing low oil pressure and forced the car into limp mode. Fixed after i changed the oil and ran MMO beforehand. Do not use this product if you’re a Honda owner!

Doesn't work. If your car has a leak just fix it. All this does is slow down the problem.

rear seal stopped leaking

I tried this on a 2016 Wrangler with a big oil leak from the rear main (lost 3qts in 5000miles) and it did stop the leakage much to my surprise (first based on significantly reduced diameter of oil spots on my driveway, then they completely disappeared by the next oil change), well enough for me to recommend it. I read some reviews on this product and at least one customer put this in his rear main differential with destructive results (increased leakage)--THIS IS INTENDED FOR REAR MAIN ENGINE SEAL, NOT REAR DIFFERENTIAL SEAL. I'm not sure if I drain the oil, will I have to do it again with the oil change? I will update this review to answer that later. Excellent product Update, changed oil and did not re-add this Blue Devil product, still no leaks, considering I had at least a 2foot diameter oil ring on my driveway at this time last year, this is a great product.

I used this 2 times now the leak never came back. The first time I used it I was really sceptical about this product still leaking for two days but as I drive along the leak suddenly disappeared. So when I did my oil change I pour another bottle no more leak up to now. I think it does its job kudos to the seller and kudos to bluedevil.

worked as described

Money wasting and very dangerous for turbo cars

Good product

After a couple of weeks it seems to be doing as advertised, time will tell.