bmwtmx wrote The issue with rod bearing failure is almost 100% driver error or lack of knowledge as to what the issue is. The issue is caused due to the fact that oil is not getting to the rod bearings when the car is cold because the oil sits lower than where the bearings are located. So, the way to resolve the problem is not rev the car over 3k RPM's until the car is warmed up. End of story.
So you're saying that the driver starts the engine, then drives like mad before the rod bearings reach full oil pressure and flow? That is what you just said. On factory rod bearings, the engine reaches 75% pressure in 2.0 seconds; and 90% pressure in 2.6 seconds. So you're saying 99% of all drivers are doing this rod bearing damage in less than 2.0 - 2.6 seconds from the time they start the engine? I say 99% because 99% of all of these engines (including the above at 7000 miles) show excessive bearing wear.
Never mind the technical reasons why that's impossible by knowing how a rod bearing works in the first place. The claim itself is silly for anybody who knows the data.
On aftermarket BE Bearings, those numbers are even better: 1.6 seconds to 70% pressure, and 1.9 seconds to 90% pressure. Oil flow more than doubles too.
However, most people rev their cars well above that as soon as they get in it and that causes the bearings to wear out as they are "oil starved" and the result is catastrophic. Buying new rod bearings does nothing because the tolerances are exactly the same meaning that the oil still has difficulty lubricating the bearings when the car is cold so if you think that you replace them once and you are done you are wrong. BMW upgraded the materials but not the tolerances so you will suffer failure regardless if you replace them if you don't allow the motor to warm up.
False, and offered with no evidence. BTW: Most people consider the rod bearing change a downgrade of materials, not an upgrade.
The picture above of a 7k mile motor is ludicrous and a total waste of money. The bearings have no wear and the driver will suffer bearing failure if he doesn't allow the car to warm up just as he would if didn't replace the bearings. I am for it on a motor with 60k+ miles but even then it depends on how the car is driven.
There are many videos and write ups on this issue but they over-hype in the forums is dumb. I am sorry you lost your motor but simply allowing the car to warm up is the way to prevent it and I practice that every time I drive my car.
The video you posted is from a company that has no engine expertise or experience. It has been widely debunked (and brutally mocked for it's errors and omissions). Believe them at your own risk.
