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Discussion Starter #1
Hi All

A relative newbie to the board here.

I have a high mileage (171K) 2003 BMW M5 that runs strong with no issues.
I am the second owner.

I have never had the oil analyzed to check for rod bearing wear and been told this is a relatively inexpensive but good idea.

Quick Question: Is there any guide/suggestion when to have this done (i.e. how many miles post-oil change) to provide meaningful results?

Thanks in advance!

John
Gainesville, FL
 

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Whenever you next decide to change the oil, take a sample (mid-stream if you're picky). In the submission process for UOA they'll want to know how many miles are on that oil in order to interpret the results for you.
 

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Discussion Starter #3
OK- thanks. I only have about 1K miles on it but was wanting to get it done AND the shop put oil I did not want in it last time, so I'd thought about changing it early- but didn't know if 1K miles would be informative for analysis.
 

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I just do it on oil changes so you know the oil has consistent mileage on it when sampled. That'll eliminate some of the variation and help you detect changes in the health of the engine.

If you've never done it before and are curious, you can pull a sample and just see if anything is grossly high. Blackstone will be able to give you universal average data for the S62 engine so you'll have a ballpark comparison, just don't get too excited on small differences between your results and the averages.
 

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Honestly, one sample will tell you very little, unless its something in particular you are trying to nail down, like high fuel, or coolant in the oil. If the only concern is rod bearings, then you need to at least couple of samples to see the trends in metals.
 

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Discussion Starter #8
Will do!
I'm the second owner of the car that has been beautifully maintained. It runs completely strong, doesn't leak a drop of anything but it has 168K on it! The owner of a local BMW shop, who owns the exact model (2003) clued me in on all of this rod bearing stuff.

I love this freaking car so I'm thinking about dumping the $ in in preventive maintenance of new bearings if its ready- and I am thinking at this mileage it probably is.

To those that have done it- what else do you recommend doing "while they are in there"?
 

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I'm basically in the same boat as you. Too many variables with rod bearings.. They've known to go bad at either low or high mileage. Depends on how hard the engine has been run, what viscosity/type of oil, the builder (s62 are hand built).
I see it this way. 2003 is the last year of the generation. The s62 has been revised twice since 1999 to help with carbon build up (not related but proof that they're improved as years go by). Also the engine builders have had many years experience hand building the s62. Therefore a 2003 s62, at that high of mileage. If the original rod bearings were assembled at the incorrect tolerances. They would have gone bad way before 177k. Starting with an oil analysis and keep at it for every oci is key. Would also be nice to know compression numbers.
But at the end of the day if you're driving it hard and looking to do track days. A rod bearing job would be good extra insurance. Keep the bearings and share pics with us if you decide to change them!
I'd be interested to see the wear marks.
 

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Discussion Starter #10
I'm basically in the same boat as you. Too many variables with rod bearings.. They've known to go bad at either low or high mileage. Depends on how hard the engine has been run, what viscosity/type of oil, the builder (s62 are hand built).
I see it this way. 2003 is the last year of the generation. The s62 has been revised twice since 1999 to help with carbon build up (not related but proof that they're improved as years go by). Also the engine builders have had many years experience hand building the s62. Therefore a 2003 s62, at that high of mileage. If the original rod bearings were assembled at the incorrect tolerances. They would have gone bad way before 177k. I would just start with an oil analysis and keep at it for every oci. Would also be nice to know compression numbers.
I appreciate the input and thoughts. You know I bought this car from the first owner with 135K on it and it amazed me then and amazes me now what a rocket this thing is and how good it sounds. It really makes me wonder how incredible they were when brand new! I also have a very well preserved 1991 Porsche 928 S4 that I have had for 15 or so years.

Although they are apples and oranges, the M5 is SO much funner to drive!!
 

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A few quick thoughts:
You want to send it in at the normal oil change interval
You want to send in the same oil (weight, type, brand) that you regularly run
You need to do this several times in a row to establish a pattern to then monitor

Since you're worried (concerned) about the engine, and you have the "wrong" oil in it, I suggest drain the oil and remove the lower oil pan to inspect for chain guide debris. Then refill with your standard oil and run it for a full cycle before sending in for analysis. The pan drop will serve to satisfy the engine health curiosity as well as an excuse to dump the oil.

I've been sending in samples at every oil change for the past 100k miles or so, at an average of 7,000 mile intervals. Currently sitting at 295,000 miles on the original bearings and guides with no noticeable change in metals. The only problem is that since the engine burns roughly 1 quart per 1,000 miles, the metals are likely diluted, which is actually a good thing for the engine health but bad for getting any warning/notice if the numbers don't go up much.
 

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"The only problem is that since the engine burns roughly 1 quart per 1,000 miles, the metals are likely diluted, which is actually a good thing for the engine health but bad for getting any warning/notice if the numbers don't go up much."

Sorry don't mean to thread jack but I think my question to Technician117 may help others. So, technician are you concerned about the amount of oil consumption you are seeing and if not, what do you attribute the consumption to if your oil analysis is not concerning? I have read your other threads and believe you know our engines well.

I am at 183,xxx and it is my daily driver. Over the course of the last three years I have seen a jump in adding oil to roughly 1 quart every 2k miles or so. However, I also have a leaking oil plug and might have a small valve cover gasket leak to explain the increase but was wondering why you are not concerned about your oil consumption. I am hoping that my engine is fine and the consumption is not an indicator of pending doom. I have done about three oil analysis sporadically and have been told by Blackstone that all is fine.

Thanks and I apologize again for thread jacking.

Michael
 

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Discussion Starter #13
A few quick thoughts:
You want to send it in at the normal oil change interval
You want to send in the same oil (weight, type, brand) that you regularly run
You need to do this several times in a row to establish a pattern to then monitor

Since you're worried (concerned) about the engine, and you have the "wrong" oil in it, I suggest drain the oil and remove the lower oil pan to inspect for chain guide debris. Then refill with your standard oil and run it for a full cycle before sending in for analysis. The pan drop will serve to satisfy the engine health curiosity as well as an excuse to dump the oil.

I've been sending in samples at every oil change for the past 100k miles or so, at an average of 7,000 mile intervals. Currently sitting at 295,000 miles on the original bearings and guides with no noticeable change in metals. The only problem is that since the engine burns roughly 1 quart per 1,000 miles, the metals are likely diluted, which is actually a good thing for the engine health but bad for getting any warning/notice if the numbers don't go up much.
Thanks- I think I like your suggested approach. My car has always run Catrol 10W/60 as far as I know and then when I had in a local shop I only used a time or two, they put Moly Specialties 5W/30 in it. Anyway, I think I will go ahead and change it out to 10W/60 and then have it tested at the next change interval as you suggest. And I am definitely heartened to hear of your 295,000 miles on the clock with the original bearings and guides!

John
 

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"The only problem is that since the engine burns roughly 1 quart per 1,000 miles, the metals are likely diluted, which is actually a good thing for the engine health but bad for getting any warning/notice if the numbers don't go up much."

Sorry don't mean to thread jack but I think my question to Technician117 may help others. So, technician are you concerned about the amount of oil consumption you are seeing and if not, what do you attribute the consumption to if your oil analysis is not concerning? I have read your other threads and believe you know our engines well.

I am at 183,xxx and it is my daily driver. Over the course of the last three years I have seen a jump in adding oil to roughly 1 quart every 2k miles or so. However, I also have a leaking oil plug and might have a small valve cover gasket leak to explain the increase but was wondering why you are not concerned about your oil consumption. I am hoping that my engine is fine and the consumption is not an indicator of pending doom. I have done about three oil analysis sporadically and have been told by Blackstone that all is fine.

Thanks and I apologize again for thread jacking.

Michael
Michael,

My S62 has fluctuated consumption over the years but in each case it was due to either external leaks, vacuum leaks or Vanos issues. Pretty much all of those reasons for burning more confirm that the reason it's always burned oil is from the oil control rings on the pistons which were updated by BMW not long after my engine was built. In the long haul, the consumption has not really changed. I've put about 180,000 of the 295,000 on the engine. When there are no underlying problems affecting it, the consumption is always around 1,200-1,300 miles per quart for the first 2 quarts and then as the oil wears the consumption slowly goes up. When it gets down around 900 miles to a quart and I've done at least 5,000 miles, I'll change the oil and start over. As I stated before, I generally run about 7,000 miles between changes. Blackstone has stated on multiple occasions that I could go longer since the new oil keeps the numbers in balance.

The key for consumption changes is mostly to check for leaks. Usually if there are vacuum or Vanos related problems, they will be showing their own symptoms. Increased consumption isn't really an indicator of engine health on this platform (S62) but that doesn't mean it can't be. Run a lean tune for long enough and the rings will burn out.
 

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I'm basically in the same boat as you. Too many variables with rod bearings.. They've known to go bad at either low or high mileage. Depends on how hard the engine has been run, what viscosity/type of oil, the builder (s62 are hand built).
I see it this way. 2003 is the last year of the generation. The s62 has been revised twice since 1999 to help with carbon build up (not related but proof that they're improved as years go by). Also the engine builders have had many years experience hand building the s62. Therefore a 2003 s62, at that high of mileage. If the original rod bearings were assembled at the incorrect tolerances. They would have gone bad way before 177k. Starting with an oil analysis and keep at it for every oci is key. Would also be nice to know compression numbers.
But at the end of the day if you're driving it hard and looking to do track days. A rod bearing job would be good extra insurance. Keep the bearings and share pics with us if you decide to change them!
I'd be interested to see the wear marks.
You know the next generation of owners are in when new oil threads pop up. Lmao

Heres some info for your thoughts. My 2000 went all the way to 195k miles before it needed bearings and i believe that was from running it low on oil. Not because its an older model. But anyways, $1000 in parts and a weekend will resolve that issue.

Oh and make sure you guys are runnin 10W60 LM.


Sent from my iPhone using Tapatalk
 

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You know the next generation of owners are in when new oil threads pop up. Lmao

Heres some info for your thoughts. My 2000 went all the way to 195k miles before it needed bearings and i believe that was from running it low on oil. Not because its an older model. But anyways, $1000 in parts and a weekend will resolve that issue.

Oh and make sure you guys are runnin 10W60 LM.


Sent from my iPhone using Tapatalk
For sure lol I've been a long time lurker and the search bar is my friend!
 

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So Tim, I get what you are saying, that UOA may be not useful in your situation. Are you just going to keep following the numbers? I'm in a worse situation, high-ish miles, moderate oil consumption, and high lead and copper numbers although they are stable over time. Feels like I'm playing Russian roulette every time I hammer the throttle lol.
 

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So Tim, I get what you are saying, that UOA may be not useful in your situation. Are you just going to keep following the numbers? I'm in a worse situation, high-ish miles, moderate oil consumption, and high lead and copper numbers although they are stable over time. Feels like I'm playing Russian roulette every time I hammer the throttle lol.
Yeah I have no plans to open this engine. With the mileage on it, it would be silly to rebuild it. I already have a 100k mile engine sitting in my garage that I will go through with new bearings, guides, etc and maybe some ported heads when the day comes that the original engine gives up.

Do you get Blackstone reports or another lab? What are your copper, lead, iron and aluminum numbers?
 

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Michael,

My S62 has fluctuated consumption over the years but in each case it was due to either external leaks, vacuum leaks or Vanos issues. Pretty much all of those reasons for burning more confirm that the reason it's always burned oil is from the oil control rings on the pistons which were updated by BMW not long after my engine was built. In the long haul, the consumption has not really changed. I've put about 180,000 of the 295,000 on the engine. When there are no underlying problems affecting it, the consumption is always around 1,200-1,300 miles per quart for the first 2 quarts and then as the oil wears the consumption slowly goes up. When it gets down around 900 miles to a quart and I've done at least 5,000 miles, I'll change the oil and start over. As I stated before, I generally run about 7,000 miles between changes. Blackstone has stated on multiple occasions that I could go longer since the new oil keeps the numbers in balance.

The key for consumption changes is mostly to check for leaks. Usually if there are vacuum or Vanos related problems, they will be showing their own symptoms. Increased consumption isn't really an indicator of engine health on this platform (S62) but that doesn't mean it can't be. Run a lean tune for long enough and the rings will burn out.
Tim,

Thanks for the detailed response. I will just keep watching my consumption together with the UOA. I was more concerned that high or increased oil consumption could only mean the engine was on the way out.

Thanks to MemphisSlim for starting the thread which has provided me with useful information.

Everyone enjoy the holidays !
 

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Yeah I have no plans to open this engine. With the mileage on it, it would be silly to rebuild it. I already have a 100k mile engine sitting in my garage that I will go through with new bearings, guides, etc and maybe some ported heads when the day comes that the original engine gives up.

Do you get Blackstone reports or another lab? What are your copper, lead, iron and aluminum numbers?
Blackstone
Aug '18 Apr '19 Unv.Av.
Cu - 27 - 14 - 6
Pb - 19 - 9 - 4
Fe - 11 - 8 - 13
Al - 5 - 4 - 5
 
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