I've always used Mobil 1 5W-20, but O'Reilly has a sale going on with 5 quarts of Castrol Edge Synthetic and a Mobil 1 oil filter for $32 so I picked up some 5W-20 for my jeep and some 5W-30 for my daughter's car.

I drained the old oil out and put in the new oil. I noticed when I was pouring the oil in that it seemed really thin, almost the consistency of water, and this was with the oil sitting in the garage in 50 degree weather for a couple hours. The color looked off too, it was a very light gold color, nearly translucent.

I started the jeep and everything seemed fine. I went for a twenty minute drive and when I pulled into the garage I could hear a constant knock. It sounded exactly like a start-up knock that never ends. I turned the engine off and on a couple times and the knock didn't go away.

I knew it had to be the oil so I drained out the oil that I had just put in less than an hour earlier and put in the 5W-30 that was supposed to go in the car. The 5W-30 looked more like oil was supposed to look. It was thicker and darker, more like I'm used to seeing with the Mobil 1 5W-20. I started up the jeep, drove around for a while and never heard a knock.

So this is just a fair warning that if you see this deal, stay away from the Edge synthetic 5W-20. I've learned my lesson. When it's time to change my oil again, I'm going back to Mobil 1.

 

I have always used Mobil 1 in all my cars and it has never let me down. From family cars to sports cars to SUV's and trucks. I always use Mobil 1

 

Thanks for the heads up. I have used edge for a while but in5w30. won't use it in my new jeep now.

 

I use the edge 5-20 with no problems or noise I would save that oil and call castrol

 

Well, it was thinner oil...if i use thin oil (0-20 OR 5-20) in my Viper engine, it makes more noise than a box full of rocks...when i use 5-30 the valve train noise goes away.

 

I just always use what mfg recommends

 

My lifters started making a racket after I switched from 5w-30 (Dealer filled it with that after a shortblock replacement and new lifters) to some cheap 5w-20 Dino oil for the rest of the break in. I'm getting ready to go back for more engine work in a week or two because my engine sounds just as bad as when I needed a whole new shortblock.

 

Too late, it's already gone in the jug with the rest of the used oil. But the oil from the last bottle was just as thin as the first bottle so I doubt Castrol would say it's their product.

 

Were the factory seals intact on the Castrol containers? Just a thought...

 

Yep, I actually bought an unopened box of six. But since it amounted to less than $5/ea, I'm just going to write this off as a lesson learned and use Mobil 1, like I have done for the past 3 years.