What’s one thing S54 owners worry about? That’s right, rod bearings: Are they good or are they about to fail and wipe out the entire engine?
[E46-chassis BMW M3 | Buyer's Guide]
Gulp.
We’ve had this in the back of our mind ever since we bought our 2004 BMW M3. Even though t…
I think one of the MOST important points on this article is the warming up of the engine. I myself never let it sit for that long, but drive it extremely slow, under 2k rpms for about two miles and then dont go over 3 until the oil gets to temp.
Luckily these cars have an oil temperature gauge. If you use the water temperature gauge as a guide, you would be fooling yourself into thinking the engine is at operating temperature when its really not. It takes a long time for the oil to come to temperature, probably a good 7 miles.
This is my engine after a good 3 miles. You can see how the coolant is all warmed up while the engine oil is not:
My bearings after 98k miles, granted there are quite a few track miles on them at this point.
You can diy this job easily for about $600. I spent around $1500 and did all new front suspension, gaskets, motor mounts, etc. Those are all easy while in there jobs.
I used WPC treated factory bearings. We'll see how they did in 50k miles.
Slippery said:I think one of the MOST important points on this article is the warming up of the engine. I myself never let it sit for that long, but drive it extremely slow, under 2k rpms for about two miles and then dont go over 3 until the oil gets to temp.
It's my understanding that you should do this regardless of what you drive (especially when it's really cold out).
I don't have the resources or findings to back up this claim, but being a little extra careful can't hurt, right?
I agree with not beating on any engine until it's good and warm. Full oil temp will usually be a good 5 minutes after full coolant temp. And on most BMWs, the coolant temp gauge shows "normal" over a pretty wide range. So it's usually 3 - 5 minutes from when the gauge hits center to when the coolant is really up to temp. Meaning for BMWs without an oil temp gauge, wait closer to 10 minutes after the temp gauge hits the center before beating on it.
I bought my M3 with 93K on it and unknown bearing history. Since it was intended to be a race car I did the bearings immediately, they definitely needed it although none were as bad as Slippery's #5. Worse than his #1 though.
100 track hours later (around 7-8K miles) it was time again, they looked like this:
OEM bearings, all hard track use, albeit always with redline oil and always warmed up. Yeah, they're a consumable maintenance item.
In reply to codrus (Forum Supporter) :
Ignoring race miles, if you use a 100k mile interval, even at $2k is not a lot of money per mile as piece of mind insurance.
And yes, I agree about always warming up any and all cars. I guess my point was more to not go by the water temperature gauge, as its diceiving.
In reply to Slippery :
You're right, that's not crazy insurance.
The biggest thing was finding a local shop to do the work. Did I really need to drag the car hundreds of miles to get the job done? And why wouldn't our local BMW shop do the job?
I had a few people recommend a shop an hour away in Orlando. I talked to the owner, and he was a GRM fan. One catch: They're only working on their race effort, so no outside jobs.
Womp, womp.
Tim recommended the stop that finally did the work. Being able to drop off the car and then bike home was huge.
My S54 engined car doesn't even have a proper coolant temp gauge, just a lit sector above the tach that indicates warming progress without numbers. I use the oil temp gauge exclusively to govern when I feel confident in being able to run the engine up the rpm range.
I have used oil temp gauges in my race cars for decades and feel kind of abandoned without sufficient information when I don't have that in a street car; BMW is the only one I have owned that has oil temp indicated.
In reply to codrus (Forum Supporter) :
Your picture didn't come through.
Slightly off- topic: Has there ever been an explanation on why this seems to affect the high-output BMW engines more than the Japanese manufacturers, or is it just in how it's reported?
CAinCA said:In reply to codrus (Forum Supporter) :
Your picture didn't come through.
Hm. It comes through for me on various desktop browsers (what I normally use), but when I look at it on my phone it's missing. That's weird.
Parker with too many Projects said:Slightly off- topic: Has there ever been an explanation on why this seems to affect the high-output BMW engines more than the Japanese manufacturers, or is it just in how it's reported?
I have read speculation that the root of the problem is the width of the bearings. It is highly desirable for BMW to keep the engine as short as possible since it's a longitudinally mounted inline 6, and adding bearing width increases the length of the engine, weight of crank, weight of cams, etc. Most 8K+ Japanese engines are Honda inline 4s, which changes things significantly.
The rapid wear in the track use example makes me think that either the oiling system is inadequate and can't maintain a sufficient oil film in the bearings or the bearings are just too small for the load being applied and no reasonable oil quantity/pressure and viscosity to the bearing will be sufficient.
codrus (Forum Supporter) said:Parker with too many Projects said:Slightly off- topic: Has there ever been an explanation on why this seems to affect the high-output BMW engines more than the Japanese manufacturers, or is it just in how it's reported?
I have read speculation that the root of the problem is the width of the bearings. It is highly desirable for BMW to keep the engine as short as possible since it's a longitudinally mounted inline 6, and adding bearing width increases the length of the engine, weight of crank, weight of cams, etc. Most 8K+ Japanese engines are Honda inline 4s, which changes things significantly.
I seem to remember that the 2003.5+ S54s have wider bearings. I have a 2004 M3 and also a 2002 engine, but I have not taken the early engine apart to check. They definitely use different bolts, the early ones are reusable and the later ones are not.
The width problem is real, but whenever you spin engines this high, bearings will become consumables. The Honda S2000 suffers from the same issue with rod bearings, albeit no as bad.
You guys are running a 10w-60 weight Group V oil in those S54 motors, correct? A good friend with one of those said something about "distilled from the tears of Bavarian woodland elves". On a serious note, I have to follow a similar warm up procedure with a built LS engine, that due to specific bearing clearances requires 15w-50 oil all the time. Takes awhile to warm it up to 170 degree, so the oil temp reading is up on the DIC at the times.
In reply to deaconblue :
I use BMW 10w60, yes. Not sure whether its Group V or not.
I might switch to the Redline version to test it out.
I do have Blackstone check at every oil change, usually 4500 miles, and they said that it remains a 10w60 at those intervals. I used to change it around 7500 and the oil was not happy.
Mine gets Redline 40WT race oil (which is not the straight-weight oil that the name would imply). It's a race car though, no street driving.
Slippery said:In reply to deaconblue :
I do have Blackstone check at every oil change, usually 4500 miles, and they said that it remains a 10w60 at those intervals. I used to change it around 7500 and the oil was not happy.
Very good point, how long does the HTHS value last before it starts breaking down.
codrus (Forum Supporter) said:Parker with too many Projects said:Slightly off- topic: Has there ever been an explanation on why this seems to affect the high-output BMW engines more than the Japanese manufacturers, or is it just in how it's reported?
I have read speculation that the root of the problem is the width of the bearings. It is highly desirable for BMW to keep the engine as short as possible since it's a longitudinally mounted inline 6, and adding bearing width increases the length of the engine, weight of crank, weight of cams, etc. Most 8K+ Japanese engines are Honda inline 4s, which changes things significantly.
Does that also apply to the high revving BMW V8s with similar bearing issues?
Slippery said:codrus (Forum Supporter) said:Parker with too many Projects said:Slightly off- topic: Has there ever been an explanation on why this seems to affect the high-output BMW engines more than the Japanese manufacturers, or is it just in how it's reported?
I have read speculation that the root of the problem is the width of the bearings. It is highly desirable for BMW to keep the engine as short as possible since it's a longitudinally mounted inline 6, and adding bearing width increases the length of the engine, weight of crank, weight of cams, etc. Most 8K+ Japanese engines are Honda inline 4s, which changes things significantly.
I seem to remember that the 2003.5+ S54s have wider bearings. I have a 2004 M3 and also a 2002 engine, but I have not taken the early engine apart to check. They definitely use different bolts, the early ones are reusable and the later ones are not.
The width problem is real, but whenever you spin engines this high, bearings will become consumables. The Honda S2000 suffers from the same issue with rod bearings, albeit no as bad.
The width issue is real. S54s have the same bore spacing as the M20s in E30s. Which is why you can use an S54 crank to build a stroker M20.
So you have rod bearings designed to handle 167hp and 6k rpm, needing to handle 333hp and 8k+ rpms. I think Keith has pointed out the math before about how the load ramps up more with RPMs vs something like boost.
In reply to aw614 :
Yes, they use the same bearings. Actually the early S65s are made of a material that makes it hard for people like Blackstone to be able to tell you when things are going south.
I have 110k miles on my S65 e92 M3. Have been thinking of doing the bearings on that car more and more.
In reply to z31maniac :
On the flip side, you can say that the M20 is overbuilt 
I am using an M54B30 crank on my M20 stroker. Need to check the bearing widths on that crank to see if they are the same as the S54.
In reply to Slippery :
Can E92 M3 bearings also be changed from below?
In reply to David S. Wallens :
Yes, same process as the e46. I contemplated doing a few weeks ago when I did the clutch and the transmission was out but did not have the parts.
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