2008 90k Miles Rod Bearings Replacement

[bdaddylo]

Had the pleasure of helping a friend change out his rod bearings on his 2008 E90 M3 with 90k miles. Special thanks to member JoeC who shed some blood going bare-handed in the effort. Apparently, he doesn't like using protection. We were fortunate that the sub-frame was already dropped for us and the car was on a lift, so all we had to do was drain the oil, drop the pan and change out the bearings. By no means am I trivializing our portion of the work. Dropping the oil pan and keeping track of the different bolts is tedious. I don't know how some did this job on their backs with the car on jack stands. We finished in about 5 hours. The owner went with ARP connecting bolts and was forced to go with the VAC coated bearings as those were the only bearings readily available. There was side to side play and we didn't measure the clearance. The top bearings on cylinders 6 and 8 had the most wear. Enjoy the pics.

[Sephiroth]

Nicely done! Seems like some of the bearings are approaching catastrophic failure.

[X5-User]

They seem fine to me

[Cbozz]

keep us posted on the oil analysis after driving for a while, i wonder how it will work out without measuring the clearance...

[eddunn]

Originally Posted by Cbozz

keep us posted on the oil analysis after driving for a while, i wonder how it will work out without measuring the clearance...

What percentage of the rod bearing replacement jobs have had the bearing clearance measured with plastigage? My guess is very few. If measured, the clearance couldn't be adjusted, as this would be done with X bearing shells. Which are not available. You could measure the thickness of each shell and perhaps come up with half a thousandths clearance. The rod side clearance issue can't be resolved either, measuring gives you an idea if it's an issue, but it too can't really be fixed with out complete disassembly if the engine.
I think that using a non OEM bolts, installing bearings into unmeasured housing bores, which can cause huge out of round issues in the housing bore, is possibly more detrimental.
Furthermore, if the heads were pulled, rods and pistons were removed, the rods have cracked caps, which can't be resized unless over sized shells with a larger backing is available.

So, you should be more thoughtful about your ... comments and know what you're typing about.

[bbrf033]

Originally Posted by Cbozz

keep us posted on the oil analysis after driving for a while, i wonder how it will work out without measuring the clearance...

Thank you......

[IIAp3x]

Good job! I must say they are not the best seen but certainly not the worst shape either...

[bbrf033]

First off, I want to thank Richard Lo and his friends/brothers Frank and Joe as well as Tobin. It was one of the best Saturday's I have had in a while. We all learned something and end the end, we believe we achieved a good result (Blackstone will confirm). The bearing change was based purely on opportunity as I put a trailer hitch through my grill and had the car in the best collision shop in HTown. Thanks to Andy and Metropolitan Collision for removing the sub-frame and giving me access to the shop and lift. As Richard said, i cannot imagine doing this on jack-stands. As i said, this was an opportunity for approx $1,000 to replace my bearings weather they needed it or not. If they were good, i "wasted $1,000. If they needed replacement, i saved about $12,000. Using the below the car method, the only thing that can be accomplished is a rod bearing change. You cannot correct anything else, so focus on the task at hand. You saw pictures of the bearings. The pictures look worse than they are. The copper showing on a few of the upper bearings as well as the coating above that is worn away looks bad, but the various layers are moles thick. They may look worn out, but the bearings are still smooth and slick. More importantly, the crank journals look as new. This is not a catastrophic failure by any means, but these bearings would eventually fail. 10K, 20K more miles, who knows. My oil analysis had not detected anything out of tolerance, but the oil we drained during the process may have said otherwise. The oil was cold and sitting for days, so I did not sample it. I will test and sample at an early oil change to see if anything pops up.
Measuring the journals, free play, the rod bore shape, the bearing thickness at each point were out of scope for this build. End of story. Despite all of the writing and you tube videos, you cannot fathom the complexity of this job until you have performed it. It makes me laugh. Step 1, Remove sub frame. Step 2 drain oil and remove oil-pan.... Each of those "steps" are like 3 hours each. The bearings only took us an hour or so.
Without the sub frame part, i think we could do this again in half the time. We were just being cautious. It was fun, did i already mention that?
As the team can attest, the car is in great shape. It has been my daily driver and though i prod the engine, it has been babied, especially for startup and cool-down. Oil changes and oil analysis at 7,500 miles which (contrary to popular opinion) is almost too often given how it was driven. We used a snake scope, and found the intake valves to be as shiny as new. Spotless! Thank you Tier1 gasoline. The car itself has been rock solid and problem free. It is my 3rd new BMW and has been by far the most rewarding and problem free. The clutch is beautiful and shows little wear thanks to never dumping the clutch (ever) the two disc design. The clutch take-up is so easy and smooth, you can take off in 2nd without stalling to save fuel (RPM's are the bane of fuel economy) and make light to light drives easier. The decent torque with the hill hold feature make it so easy to drive it is ridiculous. Anyone can do it. Really!
Due to family changes, I will probably have to part ways with it in a few months after testing the oil a few times. For a family of four, this thing was way more than adequate. For a family of 6, that is another story all together. A guy at work has a new M4 (I only drive 4 doors) with optional exhaust. Though it is a technical tour-de-force, It sounds like a 2 cylinder John Deere from the 40's. I will miss that glorious V8 and the beautiful induction and exhaust sounds it emits. Thanks again to the guys. This post is a tribute and a thank you rather than a "here's how to do it right". Please keep that in mind.

[bbrf033]

First off, I want to thank Richard Lo and his friends/brothers Frank and Joe as well as Tobin. It was one of the best Saturday's I have had in a while. We all learned something and end the end, we believe we achieved a good result (Blackstone will confirm). The bearing change was based purely on opportunity as I put a trailer hitch through my grill and had the car in the best collision shop in HTown. Thanks to Andy and Metropolitan Collision for removing the sub-frame and giving me access to the shop and lift. As Richard said, i cannot imagine doing this on jack-stands. As i said, this was an opportunity for approx $1,000 to replace my bearings weather they needed it or not. If they were good, i "wasted $1,000. If they needed replacement, i saved about $12,000. Using the below the car method, the only thing that can be accomplished is a rod bearing change. You cannot correct anything else, so focus on the task at hand. You saw pictures of the bearings. The pictures look worse than they are. The copper showing on a few of the upper bearings as well as the coating above that is worn away looks bad, but the various layers are moles thick. They may look worn out, but the bearings are still smooth and slick. More importantly, the crank journals look as new. This is not a catastrophic failure by any means, but these bearings would eventually fail. 10K, 20K more miles, who knows. My oil analysis had not detected anything out of tolerance, but the oil we drained during the process may have said otherwise. The oil was cold and sitting for days, so I did not sample it. I will test and sample at an early oil change to see if anything pops up.
Measuring the journals, free play, the rod bore shape, the bearing thickness at each point were out of scope for this build. End of story. Despite all of the writing and you tube videos, you cannot fathom the complexity of this job until you have performed it. It makes me laugh. Step 1, Remove sub frame. Step 2 drain oil and remove oil-pan.... Each of those "steps" are like 3 hours each. The bearings only took us an hour or so.
Without the sub frame part, i think we could do this again in half the time. We were just being cautious. It was fun, did i already mention that?
As the team can attest, the car is in great shape. It has been my daily driver and though i prod the engine, it has been babied, especially for startup and cool-down. Oil changes and oil analysis at 7,500 miles which (contrary to popular opinion) is almost too often given how it was driven. We used a snake scope, and found the intake valves to be as shiny as new. Spotless! Thank you Tier1 gasoline. The car itself has been rock solid and problem free. It is my 3rd new BMW and has been by far the most rewarding and problem free. The clutch is beautiful and shows little wear thanks to never dumping the clutch (ever) the two disc design. The clutch take-up is so easy and smooth, you can take off in 2nd without stalling to save fuel (RPM's are the bane of fuel economy) and make light to light drives easier. The decent torque with the hill hold feature make it so easy to drive it is ridiculous. Anyone can do it. Really!
Due to family changes, I will probably have to part ways with it in a few months after testing the oil a few times. For a family of four, this thing was way more than adequate. For a family of 6, that is another story all together. A guy at work has a new M4 (I only drive 4 doors) with optional exhaust. Though it is a technical tour-de-force, It sounds like a 2 cylinder John Deere from the 40's. I will miss that glorious V8 and the beautiful induction and exhaust sounds it emits. Thanks again to the guys. This post is a tribute and a thank you rather than a "here's how to do it right". Please keep that in mind.

[Cbozz]

Originally Posted by eddunn

What percentage of the rod bearing replacement jobs have had the bearing clearance measured with plastigage? My guess is very few. If measured, the clearance couldn't be adjusted, as this would be done with X bearing shells. Which are not available. You could measure the thickness of each shell and perhaps come up with half a thousandths clearance. The rod side clearance issue can't be resolved either, measuring gives you an idea if it's an issue, but it too can't really be fixed with out complete disassembly if the engine.
I think that using a non OEM bolts, installing bearings into unmeasured housing bores, which can cause huge out of round issues in the housing bore, is possibly more detrimental.
Furthermore, if the heads were pulled, rods and pistons were removed, the rods have cracked caps, which can't be resized unless over sized shells with a larger backing is available.

So, you should be more thoughtful about your ... comments and know what you're typing about.

I was just unsure of the need of measuring it but that's a good news that without that step it all can go well... that will save me some $ when I get to change my own bearings!!

[nholmes]

[Time Lord]

they look good to me also

[///M Power-Belgium]

Originally Posted by nholmes

I saw that guy before on here...

[nholmes]

Originally Posted by ///M Power-Belgium

I saw that guy before on here...

He's famous.

[///M Power-Belgium]

Originally Posted by nholmes

He's famous.

That's because he's Belgian ...

[aus]

How come we NEVER see the non-Believers on these threads??
.

[admranger]

Originally Posted by aus

How come we NEVER see the non-Believers on these threads??
.

We do, but they usually say: 'those bearings are fine and would have lasted another 110k miles' or some other non-provable claim.

[bigjae1976]

Those bearings are fine...good for another 110k miles.

Not sure what the fuss is about.

lol

[admranger]

Originally Posted by bigjae1976

Those bearings are fine...good for another 110k miles.

Not sure what the fuss is about.

lol