BMW designed the S54 engine with approximately half the industry standard oil clearance. This move is seen as trendy among some manufacturers as it can potentially increase gas mileage and horsepower. However, when this design choice is made, like in the Toyota Prius, the manufacturer also specifies a very thin oil to match the small oil clearance.
BMW, on the other hand, took a different route by using very small oil clearance and a very thick 10W60 oil in their engines. This decision has raised concerns among experts and enthusiasts alike, as it deviates from the industry norm. Many consider this combination to be a recipe for disaster.
Engines with clearances that are too small, paired with oil that is too thick, can lead to premature rod-bearing related engine failures. When the clearances are too tight and the oil is too thick, the lubrication around the bearing becomes marginal. This can result in some metal-to-metal contact, leading to increased wear and potential engine damage.
Proper lubrication is crucial for the longevity and performance of an engine. When the oil clearance is too small and the oil is too thick, the lubrication properties are compromised, putting the engine at risk of failure. It is essential for auto manufacturers to carefully consider the oil clearance and viscosity to ensure optimal engine performance and durability.
This is a serious concern for M3 owners, especially those that have higher mileage or are supercharged/tracked often. Engines with clearance too small, coupled with oil too thick, lead to premature rod-bearing related engine failures.
With clearance too small and oil too thick, the lubrication around the bearing is marginal. Some metal-to-metal contact is made between the bearings and rod journal. The oil and rod bearings overheat. Some bearings seize on the crankshaft, while others will "spin" and cause a crankshaft failure.
It's rare to see bearings without at least some sort of premature surface wear, so it's good to address this issue promptly. For those looking to keep their vehicles for extended use, our S54 Rod Bearing Service is a must.
Don't wait until it's too late to prevent potential engine failures. Regular maintenance and addressing known issues can help prolong the life of your M3.
