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    • BMW S85 V10 rod bearing issues becoming more prevalent as E60 M5 and E63 M6 vehicles reach higher mileage

      Motor bearings. The one main area of weakness in naturally aspirated M motors. The S54 motor in the E46 M3 was notorious for bearing issues getting an early reputation as being made out of glass as motors failed left and right. BMW eventually issued a recall and the S54 now is known as one of the greatest M motors ever produced by BMW and having a modern reputation as being very stout taking just about whatever one throws at it.

      The S85 V10 did not experience a rash of early failures like the S54 due to the bearings and neither did the S65 V8 in the E9X M3 based on it. However, as the motors reach higher mileage it is becoming clear the motors suffer from unnaturally high rod bearing wear. Why is this? One reason is that the pistons and rods may be a bit too heavy for such a high revving motor (despite BMW's marketing they go with what is cheapest in modern times) causing more wear than normal. The oiling system especially in the S65 V8 is weak so track junkies have been experiencing rod bearing wear issues.

      This problem is known in E9X M3 circles with the S65 V8 but it is now coming out with the S85 V10. Why later on the S85? Because the S85 has a slightly different oiling system (BMW went even cheaper on the S65 and this is why a dry sump oiling system is recommended for track guys) and because S85 owners only now are supercharging which puts more stress on the motor. There are more S65 V8's tracking and supercharged so the issue is far more well known with the V8 than with the V10.

      For those doubting, here is a picture of BimmerBoost user @CV10T's rod bearings at 91k miles from his S85 V10. Not particularly pretty are they?

      So what can one do to prevent premature bearing wear and even worse a motor failure? Well, frequent oil changes are recommended to remove any material in the oil. Secondly, replacing the factory bearings with a set of aftermarket bearings is a good idea. The job is not that bad as @CV10T stated replacing his bearings cost 15 hours of labor plus the cost of the bearings.

      BimmerBoost vendor VAC Motorsport has several coated bearing options available including those for the S85 V10 and S65 V8.

      Gentlemen, take care of this problem before it's too late especially if you do a lot of spirited driving at high RPM or have a power adder.

      This article was originally published in forum thread: Rod Bearing Issue becoming more common on high mileage S85s started by CV10T View original post
      Comments 39 Comments
      1. Team Plutonium's Avatar
        Team Plutonium -
        Click here to enlarge Originally Posted by alex@ABRhouston Click here to enlarge
        custom coatings only add about 0.0003" of thickness- you cant hardly even measure that without precision equipment lol
        Yes, a yard stick won't do here.
      1. bobS's Avatar
        bobS -
        Ok dumb question here.... I'm about to get a m3 once my 335 sells...am I crazy? This rod bearing issue is no joke. I guess changing oil every 3500 miles and getting a blackstone report every other change would help?

        If a car is running fine at 35-45k miles...isnt it safe to say it's not one of the cars with this issue? I'm looking at used m3's with that milage...
      1. Group.america's Avatar
        Group.america -
        I'm getting mine redone on an E46 right now... better to spend the low $k than blow up when I go FI
      1. inlineS54B32's Avatar
        inlineS54B32 -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        Ok dumb question here.... I'm about to get a m3 once my 335 sells...am I crazy? This rod bearing issue is no joke. I guess changing oil every 3500 miles and getting a blackstone report every other change would help?

        If a car is running fine at 35-45k miles...isnt it safe to say it's not one of the cars with this issue? I'm looking at used m3's with that milage...
        @bobS, it depends on the year of the car IMO. If it's an early e46 M3 (2001-2002 IIRC), they had issues with the rod bearing becoming misaligned - causing the crankshaft to move out of alignment... BMW had a TSB (or whatever it's called) - and fixed these - and you CAN see if the work has been done, and/or if the engine is one that has the bad bearings.

        I haven't heard of many people having issues other than the ones in the above boat. I almost think that the S65 is worse off than the S54 in this regard if the S54 has been repaired.

        I guess blackstone reports are good and all, but 3500 mile oil changes is a little much IMO. I go every 5k in my car, and the computer tells me it's fine; however, I am a bit concerned due to the fact that I probably have spent most of the car's life at or above 4k RPM (even at 90 MPH on the highway in 7th gear it's right around 3700) - but so far it's been fine. Once the engine is out of warranty, I will have someone rip it apart and replace the bearings, until then - if it fails, I'll let warranty pick it up. Point is, I wouldn't be as concerned with the previous gen.
      1. bobS's Avatar
        bobS -
        Click here to enlarge Originally Posted by inlineS54B32 Click here to enlarge
        @bobS, it depends on the year of the car IMO. If it's an early e46 M3 (2001-2002 IIRC), they had issues with the rod bearing becoming misaligned - causing the crankshaft to move out of alignment... BMW had a TSB (or whatever it's called) - and fixed these - and you CAN see if the work has been done, and/or if the engine is one that has the bad bearings.

        I haven't heard of many people having issues other than the ones in the above boat. I almost think that the S65 is worse off than the S54 in this regard if the S54 has been repaired.

        I guess blackstone reports are good and all, but 3500 mile oil changes is a little much IMO. I go every 5k in my car, and the computer tells me it's fine; however, I am a bit concerned due to the fact that I probably have spent most of the car's life at or above 4k RPM (even at 90 MPH on the highway in 7th
        gear it's right around 3700) - but so far it's been fine. Once the engine is out of
        warranty, I will have someone rip it apart and replace the bearings, until then -
        if it fails, I'll let warranty pick it up. Point is, I wouldn't be as concerned with
        the previous gen.

        Well I'm going for a 09-10 m3.... So I guess I'll choose wisely and replace the rod bearings before going FI
      1. inlineS54B32's Avatar
        inlineS54B32 -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        Well I'm going for a 09-10 m3.... So I guess I'll choose wisely and replace the rod bearings before going FI

        Ahh sorry about that. For some reason I thought I remembered you wanting an e46 before. Talk to VAC - they have solutions for this and have a lot of knowledge. I am sure you will be good. It's a great engine. These things are over reacted to IMO.
      1. bobS's Avatar
        bobS -
        Click here to enlarge Originally Posted by inlineS54B32 Click here to enlarge
        Ahh sorry about that. For some reason I thought I remembered you wanting an e46 before. Talk to VAC - they have solutions for this and have a lot of knowledge. I am sure you will be good. It's a great engine. These things are over reacted to IMO.
        That's what I'm telling myself too... I plan to hang onto this m3 for a long while. Since it's not my daily I'll only put 3-5k miles a year on it. I also want to go FI..... We'll see
      1. TTFS's Avatar
        TTFS -
        Just built my motor and oem bmw rod bearings for the e46 m3 was bought from the dealer and they came coated. They did not have the color spec I needed and had to get it from Germany. I am not sure if it was a new part number or what but they certainly came coated from the dealer.

        I would shy away from changing the specs on the crank when you can get a thicker bearing. This is just my preference

        Thank you VAC for the Arrow Rods Click here to enlarge
      1. BigM62's Avatar
        BigM62 -
        Click here to enlarge Originally Posted by m54b25 Click here to enlarge
        Get some TriMetal rod bearings & right clearance to rebuild S60/S65 engine that can rev.9000rpm & don't increase stock NMAX (8250/8300). I.e bearings from: HK LMP2 V8 (from Engine Developments Ltd former JUDD Power engines.)

        http://www.engdev.com/products/hk-2011-lmp2-v8/
        9K rpm's? I think I just got a little tingle. Click here to enlarge
      1. alex@ABRhouston's Avatar
        alex@ABRhouston -
        Just did an oil analysis on a new customer and his new-to-him S85...... 70K on the clock, and the oil report came back looking great!
      1. 5soko's Avatar
        5soko -
        Click here to enlarge Originally Posted by alex@ABRhouston Click here to enlarge
        Just did an oil analysis on a new customer and his new-to-him S85...... 70K on the clock, and the oil report came back looking great!
        Good to know!
      1. S62R's Avatar
        S62R -
        75k miles,full service history:


        Click here to enlarge


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      1. Sticky's Avatar
      1. S62R's Avatar
        S62R -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Looks like a large variance among the cylinders?
        All of the upper shells show copper,some more,some less....
      1. Sticky's Avatar
        Sticky -
        How much longer would that motor have lasted before a bearing change was absolutely necessary?
      1. rawad1017's Avatar
        rawad1017 -
        probably about 5-6k more miles. you should see everyone tripping out on M5board about this lol glad i don't have to worry about it for a while
      1. S62R's Avatar
        S62R -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        How much longer would that motor have lasted before a bearing change was absolutely necessary?


        It was absolutely necessary at this point already.

        It would have had severe damage(means damaged crank journals or a rod having the urge to see the daylight) within the next 1-2k.

        I just wrote a long essay regarding people wanting to file a complain at BMWNA for that "bearing issue" stuff.
        I can copy it and create a new thread over here to discuss,if you want to,Joseph.
        Think it might be quite interesting as my point is it is nothing else than engine maintenance like on many other engines the timing belt change at similar mileage for similar cost.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by S62R Click here to enlarge
        I just wrote a long essay regarding people wanting to file a complain at BMWNA for that "bearing issue" stuff.
        I can copy it and create a new thread over here to discuss,if you want to,Joseph.
        Think it might be quite interesting as my point is it is nothing else than engine maintenance like on many other engines the timing belt change at similar mileage for similar cost.
        I think that would be a very interesting read.
      1. S62R's Avatar
        S62R -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        I think that would be a very interesting read.

        Will do it today.