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Rod bearings! Am I paranoid!

8K views 55 replies 27 participants last post by  liquidsmoke 
#1 ·
Hi, I have e39 M5 in lovely condition, full history, done 149,000 miles, runs great, no funny noises, knocks or bangs from the engine. I am getting paranoid about this rod bearing issue! Have i got a time bomb waiting to get me? I don't drive the car hard or over rev it. Does anyone know of many M5's going to big mileages without new rod bearing being fitted? Thanks
 
#3 ·
There are definitely many examples of higher mileage cars with no rod bearing problems, there are also plenty of lower mileage cars with rod bearing problems!

If the car is new to you and you don't know the history in a lot of detail, I'd be thinking about getting the bearings done.
 
#10 · (Edited)
There are definitely many examples of higher mileage cars with no rod bearing problems, there are also plenty of lower mileage cars with rod bearing problems
+1

They can let go at 30K miles or 300K miles and everywhere in between. Unfortunately it's a risk we need to learn to live with. If you can afford to prevent it, you have a lot more money than I. :dunno:

To be honest, I'm more concered with VANOS solenoids or chain guides packing up w/o warning.

edit:

Although I am in the same club that says wait till you have a real issue before you throw money at the car, I say change the ROd bearings if it gives you peace of mind.

Compared to what it would cost to replace the engine or fix the damage, the Rod bearing replacement is a SMALL investment (as low as $1700 out the door).
Those figures are few and far between, my friend. I was quoted roughly $7,800 to have mine done at the dealer (a place where I receive huge discounts on everything from parts to labor) and just slightly over $6K from a local Indy. For $1700, I'd do it tomorrow.
 
#5 · (Edited)
I'm in the camp that says wait until you have a problem. If you want to be paranoid about something, worry about that asteroid that is hurtling towards Earth and will destroy all existing life. Or the solar flares that will bring down the entire electrical grid, plunging the world into darkness and anarchy.

But don't sweat the bearings, not unless you hear a knocking.
 
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#12 ·
So, we should replace the bearings for sure, as they are much more likely. Also, in the event said cataclysmic forces take place, better to know your rods are good to go the distance as you drive away from the "darkness" :wroom:

Regular oil analysis may also help spot the wear before it is too late.
Have there been examples to your knowledge where you've seen high "whatever metal" (copper?) content show a bearing problem, and then bearings get replaced remedying that trace in the subsequent samples? Just curious. I'll be sending a sample on my next change.
 
#7 · (Edited)
At first I thought you were asking for trouble considering how many paranoid preventative maintenance guys there are on this board.

But now I'm surprised at the number of sane ones who have spoken up and echoed my exact thoughts on rod bearings. :)
 
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#8 · (Edited)
Give it some more time - the balance will shift ;)
 
#14 ·
You were sooo right
 
#9 ·
Although I am in the same club that says wait till you have a real issue before you throw money at the car, I say change the ROd bearings if it gives you peace of mind.

Compared to what it would cost to replace the engine or fix the damage, the Rod bearing replacement is a SMALL investment (as low as $1700 out the door).

At the end of the day, its YOUR call. Receiving 20 responses telling you to stop being paranoid isn't going to make you think differently. Either you will continue to worry about it and let it ruin the enjoyment you get out of truly "driving" your car, OR you will decide to bite the bullet.

Good luck
 
#11 · (Edited)
I wasn't paranoid either, until my rod bearings spun at just under 100k miles. Virtually no warning, no noises. Regular maintenance. No beating on the car. No track time. Only 1 bad bearing. But that is all it took.

I think if you are over 90k miles, you should at least have the rod bearings checked (measured). I am guessing about 2-3 hours labor to drop the oil pan and take a look. Not a high $$$ item. Regular oil analysis may also help spot the wear before it is too late.

Unless they are showing wear, no need to change. Just inspect. If they are showing wear, consider yourself lucky and finish the change. Oil pan is already out, so a portion of the labor has already been paid for.

If Dinan, who is not known for being the lowest priced BMW service provider, charges around $1700, I am sure it can be done for less. I wouldn't bother with the dealer, they probably tell you to take the engine out, instead of just dropping the pan. But no harm in asking for a quote from a dealer too.

Regards,
Jerry
 
#13 ·
I agree, I would like to be educated on how oil analysis can help spot bearing wear.

I have been a little worried with cold-starts and extremely mild driving while the engine is still warming up. I get a slight metallic sound from the engine when it is cold and goes away completely when fully warmed up. It is kind of freaking me out.
 
#15 ·
I can't put my hands on it, but there have been discussions where the UOA shows a higher concentration of xx metal, which is what the bearing shells are made of. That would be an indicator. Perhaps someone else (Raiiku?, rao?, tradin1?) can tell us what to look for.....?

Regards,
Jerry
 
#16 · (Edited)
I can't put my hands on it, but there have been discussions where the UOA shows a higher concentration of xx metal, which is what the bearing shells are made of. That would be an indicator. Perhaps someone else (Raiiku?, rao?, tradin1?) can tell us what to look for.....?
I believe you're looking for lead in the UOA or specs of not so shiny metal in the oil filter. By the time you see copper, it's game over!

I think if you are over 90k miles, you should at least have the rod bearings checked (measured). I am guessing about 2-3 hours labor to drop the oil pan and take a look. Not a high $$$ item. Regular oil analysis may also help spot the wear before it is too late.
But dropping the oil pan/oil pump/etc will only provide access to 1 or 2 of the rods, it isn't all that helpful to gauge the overall condition.

Edit: Unless you're talking about the upper oil pan, but that involves dropping the subframe, 2-3 hrs sounds optimistic.
 
#17 ·
What about asking the board admin guys to set up a database that all members can input data on rod bearing failure ? To include territory,mileage, shell number that failed, oil analysis , etc etc, probably just scratching the surface here, but surely there could be a
Common denominator between US/Europe/UK models on bearing failure, just a thought so don't flame me




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#18 · (Edited)
http://www.m5board.com/vbulletin/e3...ten-me-rod-bearings-really-6.html#post2270019

Talk about a false sense of security.

If it takes 100k miles for the bearing to wear to the failure point than an oil analysis isn't going to show anything and the trace amounts will be nice and consistent. If the damage is caused by 1 or more discreet episodes then the analysis will be perfect until the incidents occur and then it will be too late.

The ONLY way to know for sure is to either wait for the bearings to fail or take the bearings outand inspect their condition.

Everyone can speculate as much as they like as to the cause and invent whatever rituals they think will help the problem, but ther fact is that no one can conclusively answer the question or determine if it is a "problem" at all or only the life span of the bearings.
Great - now we can have arguments about who does their oil analysis the most and what is the best place to have it done, methodology, etc. ad nauseum :applause:
 
#19 ·
Oil analysis won't tell you if your rod bearings are failing. It's useless in preventing that type of disaster. UOAs can tell you only if an oil is holding up, if your air intakes are free of leaks and filtering correctly, sometimes if you have a fueling issue (i.e. stuck or leaky injector), if you have a head gasket issue (coolant in oil), etc.

The wear metals themselves are probably the LEAST useful part of the entire UOA. To wit: put some sort of solvent/fuel system cleaner in your gas and watch your lead/iron/copper numbers spike. Switch to redline oil and watch your lead/iron/copper wear metals spike. Etc.

Anyway, just chiming in on that. I was schooled by Rao over many years on another forum :)
 
#24 · (Edited)
Well I wouldn't say "useless", as if the indicator is lead, I could see that as helpful. I could be wrong, but I think that automotive manufacturers would $41T a brick if lead was in gasoline additives, as this is contraindicated in preservation of the Cats, and have a hard time thinking they would allow fuel additives being used without a stink. So I am curious if there truly is any lead in these. We ran oil samples on jet engines every 10 hrs SPECIFICALLY to look at bearing condition via metal content. . . Useless may be overstating the case.

The UOA can easily be referenced against other samples of the same oil, too. Don't remember the member off hand, but he has a couple threads for piling up UOAs of oils.

Researching on my part as to what conditions lead to bearing failure (driver created conditions ie over-revving or cold revving, whatever) would likely be the best starting point and do my best to not create that condition. I just wondered if anybody had any info on the UOA and knew of any indicators correlated with Rod bearing problems/failures. :M5thumbs:
 
#25 ·
OK, I'm going to stick my head on a block and say what I think causes rod bearing wear in our cars.

[FLAME SUIT ON]
10W-60 and the misleading yellow rev counter lights!

Bearing protection is provided by the flow of oil through the bearing, the yellow tachometer lights go out before the oil is fully up to temperature, when the lights go out it gives a visual indication that it's OK to rev the engine - it's not! 10W-60 is still too thick at the temperature at which the light between 6 and 6 1/2 K rpm goes out, it will not flow enough fully protect the bearings at high rpm at this temperature.

10W-60 should be fine when full warmed up, but this takes 10 minutes at least, often significantly longer. The fact that the yellow lights have gone out is misleading, if there were no yellow lights, just the oil temperature indicator, then some people would probably rev the engine less until the oil was fully up to temperature. Better still, have the yellow lights go out at a higher temperature when the oil is truly warmed up.
[/FLAME SUIT ON]
 
#27 ·
OK, I'm going to stick my head on a block and say what I think causes rod bearing wear in our cars.

[FLAME SUIT ON]
10W-60 and the misleading yellow rev counter lights!

Bearing protection is provided by the flow of oil through the bearing, the yellow tachometer lights go out before the oil is fully up to temperature, when the lights go out it gives a visual indication that it's OK to rev the engine - it's not! 10W-60 is still too thick at the temperature at which the light between 6 and 6 1/2 K rpm goes out, it will not flow enough fully protect the bearings at high rpm at this temperature.

10W-60 should be fine when full warmed up, but this takes 10 minutes at least, often significantly longer. The fact that the yellow lights have gone out is misleading, if there were no yellow lights, just the oil temperature indicator, then some people would probably rev the engine less until the oil was fully up to temperature. Better still, have the yellow lights go out at a higher temperature when the oil is truly warmed up.
[/FLAME SUIT ON]
You might want to save that last bit for later, as a few posts will surely sear your skin now! Keep that suit on! better yet, loan it to me for a bit

[flame suit on]
My thoughts are, don't use 10w60! I have been using Mobil1 0w40 and have seen some samples of it too. But for the cold mornings and better flowability at lower temps, this makes me happy, and for my model year is actually thicker than recommended!

THIS IS NOT AN OIL THREAD! :eek:oohhh:
 
#26 ·
If it gives you peace of mind and you have an extra 3k laying around go for it. I'm not sure where these $1700 figures come from, but I've had estimates from two indys and one dealership on rod bearings ranging from $2600 to $3380 at the dealer. If you want total piece of mind go for the chain guards, fan clutch, and fuel pump too. If it was me, I'd drive it, change the oil regularly with TWS and enjoy it!
 
#33 ·
Thanks for the comments/input guys. I talked to Phil at CPC Engineering today. So I am seriously thinking of having the rod bearings done and a chain guide at the same time as the sump is off. I know if I have it done I will use the car more and I will stop worrying! Watch this space.
 
#34 ·
One fear that people have when considering Rod Bearings, apart from financial of course, is that something is going to go wrong and that the car is going to be messed up afterwards.

Well the good news for you is that fear of something going pear shaped, is thrown out of the window if it is CPC Engineering who are working on your M5 :flag: o
 
#43 ·
CPC Engineering is Simply The Best.

Just give them a call.

From memory its about £800 all in.

Basically when BMW Dealers are stumped, they call Phil Crouch :flag:
 
#37 ·
Outstanding, another oil thread, just what the doctor ordered!

Mobile posting, sorry for spelling errors. Autocorrect rarely works right...
 
#39 ·
Well, just for the sake of understanding, as I am not the one who read any spectral analysis on oil samples, but have seen the systems and looked at a few graphs/analyses.

I agree with most of your statement, and since we are at the very most doing oil samples every oil change (or maybe more if you're nuts), I also agree that the frequency of monitoring would be too low.

However, if one were consistent, given engine break in, I would be curious to see what samples looked like time after time (hmm, light bulb), and also with other cars would love to see if there were, in fact, a correlation. As I stated before, we would draw samples every 10hrs on jet engines, SPECIFICALLY to look at metal contents in concern for bearing condition. There are obvious differences in the lubrication systems, mind you, so I know that there are variables.

All I am really saying is that if you draw the sample properly (less concern of particle stream, consistently, and manage other variables to the best of your reasonable efforts, "useless" is just a bit too absolute. . . for my taste (also my opinions). Perhaps I am completely left field, but there is definitely something to be gleaned. I know it isn't specific, but the fact that it is sensitive is maybe the downfall you're getting at.

I suppose I will formally start looking into oil analysis to gain an even better understanding.

Supposing you're correct that it is useless in that regard, this is certainly the way Murphy designed it :M5thumbs: Surely it couldn't be a way to avert disaster :flag:
 
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