Rod Bearing Replacement in BMW M3 and M5

Rod bearing replacement in BMW M3s and M5s is something that our team excels at and if you own either of those beautiful machines then you should be bringing them to our team when you need general BMW service or anything done to your rod bearings.

Why do the motors blow with rod bearing failure?

BMW designed the S65 and S85 with approximately half the industry standard oil clearance.  This is a trendy move among some auto manufacturers to increase gas mileage and increase horsepower.  But when they do it, the auto manufacturer also specifies a very thin oil to match the very small oil clearance.  BMW dropped the ball here and is using very small oil clearance and very thick 10W60 oil.  Many consider this its own recipe for disaster.  But here's what is believed to be happening in the S65 and S85 engines.

Engines with clearance too small that is coupled with oil that's too thick leads 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.  Here's the recipe how it can happen. BMW designed the S65 and S85 with approximately half the industry standard oil clearance.  

    BMW Rod Bearing Replacement Form

S65 Rod Bearing

We recommend you replace the following:
- Performance Rod Bearing
​- Performance Rod Bolts

Cost Approximation
Performance Rod Bearing: $795.00
​Performance Rod Bolts: $358.00
​Labor: $1250.00
​**all parts prices are subject to change, dependent on supplier for pricing**

**If any modifications are done to your vehicle, we recommend this repair asap. This repair is highly recommended for any supercharged vehicles**

S85 Rod Bearing 

We recommend you replace the following:
- Performance Rod Bearing
​- Performance Rod Bolts

Cost Approximation
Performance Rod Bearing: $995.00
​Performance Rod Bolts: $499.00
Labor: $2860.00
**all parts prices are subject to change, dependent on supplier for pricing**

​**If any modifications are done to your vehicle, we recommend this repair asap. This repair is highly recommended for any supercharged vehicles**

Performance Bearings + Bolt

BMW S65B40 Engine

BMW S85B50 Engine