28 May 2006 BMW E60 M5 Vanos Timing
More and more we are seeing the V10s out of the E60 m5’s Developing various engine issues. While mileage is often an indication of wear, we have customers coming in with odometers ranging from 30k-140k miles, time seems to be the biggest issue as the earliest model years started failing first regardless of mileage. What issues are the S85’s running into? This list is long and includes things such as vanos camshaft control actuators, oil lines, vanos oil pumps, rod and main bearings just to name a few. It is not know for sure why exactly there are so many failures related to oil supply, there are a few theories.
Here at fluid, we have seen more than our share of S85’s. In our day in and day out of diagnosing, maintaining, and repairing these sophisticated engines we have come up with a possibility what we think may be going on.
This high RPM motor was not designed to make just 500 horsepower, they wanted to do it reliably. Unfortunately reliability and high RPM typically don’t go hand in hand. Thus the tight rod and main bearing tolerances used in order to accomplish this goal, are showing that they are not up to the task. Many vehicles of various mileages and model years are having bearings replaced because they are showing signs of accelerated wear. It is then possible that the bearing material washed into the oil is picked up by high pressure oil pump. This oil is then supplied into the vanos units causing vanos actuator issues.
Why do the bearings fail? Some think it is faulty bearing material construction, paired with the high RPM nature of the motor. Some point to the weight of the oil that BMW recommends for use in these vehicles, and the poor lubrication performance in cold weather, especially when lubricating bearing tolerances this tight. What ever the reason, some builders are recommending rod bearings as often as every 60k miles!
This 2006 BMW M5 had to have the timing checked after a VANOS solenoid replacement. The car had various faults for camshaft control on all banks (OBD P0014 P0015, or bmw 271a 271b 271c 271d). The solenoids failed the vanos test procedure we ran on all 4 camshafts. The next step was to replace the actuator solenoids, and once completed, only the P0015 or 271b VANOS control exhaust bank 1 fault re-occurred. This means that we would have to remove valve covers to check timing in order to find out what exactly was happening.
With the timing tools in place it was evident that Bank 1 exhaust camshaft was out of place. There was evidence of heat damage due to wear as well. We imagine the faulty solenoid would cause either too much or too little oil pressure to be delivered to the Vanos unit causing the gear to slam into its end stop. Here it could become stuck and thus the failure this car was experiencing with the vanos gear.
Now that we’ve checked, its obvious that unfortunately the customer neglected the vanos Solenoid codes for longer than they should have, and ended up causing the bank 1 exhaust vanos gear to seize in the fully retarded timing position. All of the solenoids needed to be replaced first, but afterwards only bank 1 exhaust was faulting, so we had to get in there in order to find the failed vanos gear by setting up the timing tools and checking the movement of the camshafts.
With the car all timed back up and the broken VANOS gear replaced the engine was finally running the way it was designed. However, with the issues that seem to be plaguing this platform, only time will tell what other issues the future hold in store. If you have and concerns regarding your BMW M5 or M6, don’t wait to get in touch with us by calling 815-230-2900, or contact us through email at email@example.com. We’re conveniently located in the Naperville/Plainfield area of the Chicago Metropolitan suburbs.