Bearing Wear

[wyshyvanuk]

Nagging questions:
1. Any comments on why lead levels would “spike” on an oil analysis, indicating the need for a bearing replacement? Wouldn’t lead levels be more linear under the same wear conditions?
2. Is it possible that a defective Constant Pressure Valve, that little nubbin down by the exhaust pipes, would frequently prevent an engine from starting with a quick supply of oil? Would an oil pressure gauge show residual oil pressure?
3. Has anyone replaced the oil pressure relief valve in the oil pump on the S54 engine during a bearing replacement? I understand that the part is available from some German parts houses even though RealOEM doesn’t list it separately.
4. Lang Engineering proposes widening the crankshaft rod bearing journals to extend bearing life to more "normal" levels. Has anyone had this done and checked the results with an oil analysis?

[jhm5]

Seems like lead levels would drop, as in no or little lead left on bearings?

[XMetal]

Originally Posted by wyshyvanuk

Nagging questions:
1. Any comments on why lead levels would “spike” on an oil analysis, indicating the need for a bearing replacement? Wouldn’t lead levels be more linear under the same wear conditions?
2. Is it possible that a defective Constant Pressure Valve, that little nubbin down by the exhaust pipes, would frequently prevent an engine from starting with a quick supply of oil? Would an oil pressure gauge show residual oil pressure?
3. Has anyone replaced the oil pressure relief valve in the oil pump on the S54 engine during a bearing replacement? I understand that the part is available from some German parts houses even though RealOEM doesn’t list it separately.
4. Lang Engineering proposes widening the crankshaft rod bearing journals to extend bearing life to more "normal" levels. Has anyone had this done and checked the results with an oil analysis?

If you look at my oil analysis and bearing thread, you'll see that mine didn't behaved like what you've described. My lead levels were trending in the teens as long as I had been doing oil analysis. I guessed I may have seen that "spike" that you're referring to had I done oil analysis since day 1?

What do you consider "normal" wear?  My lead levels have dropped to near zero (2ppm or so) after changing the bearings and I have not touched that constant pressure valve.  Is near zero lead level  "normal" enough?  Lang worked on my car and he didn't mentioned or upsell me on widening the crankshaft rod bearing journals during my service. I guessed unless you are a track rat, that might be an option.

[wyshyvanuk]

Thanks, guys. I've not done any analyses on mine, but I've read some posts that touted a lead "spike" as indicating a bearing problem. Didn't make sense to me, and I was look for additional input.
"Normal", at least to me, would be not needing to worry about bearing wear, unless the engine was thrashed either on the street or track. I know, call me naive ;~).
XMetal, you added Ceratec after the last bearing change, correct?
A couple more questions:
1. Am I correct about the purpose of that Constant Pressure Valve or does it accomplish something else entirely?
2. Are the OEM replacement bearings from BMW the newer aluminum/tin variety? I guess same question for the WPC or BE bearings.
Thanks, again, for your help!!

[XMetal]

Originally Posted by wyshyvanuk

Thanks, guys. I've not done any analyses on mine, but I've read some posts that touted a lead "spike" as indicating a bearing problem. Didn't make sense to me, and I was look for additional input.
"Normal", at least to me, would be not needing to worry about bearing wear, unless the engine was thrashed either on the street or track. I know, call me naive ;~).
XMetal, you added Ceratec after the last bearing change, correct?
A couple more questions:
1. Am I correct about the purpose of that Constant Pressure Valve or does it accomplish something else entirely?
2. Are the OEM replacement bearings from BMW the newer aluminum/tin variety? I guess same question for the WPC or BE bearings.
Thanks, again, for your help!!

I don't know how a single lead "spike" would be an indication of a bearing problem, other than a specific event that would have caused it to spike. I don't understand that logic either. The only sure way of interpreting oil analysis results properly is to look at trends over many tests, especially if you can start from day 1. Otherwise, just seeing low lead level on your first test after 50k mile may give you a false sense of security as there could possibly be not much lead left on the bearings to produce anything on your oil analysis.

I've used a treatment of Ceratec prior to the bearing change just for experimentation and was very surprised to see a drop in lead level from it (from my average teens to 5ppm!). After seeing that result, I've decided to use another treatment of Ceratec after the bearing change as well.

As far as I know and from all the research that I've done, the OE replacement bearings from BMW is still made of the same materials as the original bearings (steel/copper/lead). Only the later S65 motors start using the newer aluminum/tin variety. WPC is just a surface treatment (not a coating) done to the OE bearings or any brand of bearings you sent to them for the treatment. So, when people talk about WPC bearings, it's usually WPC treated OE bearings.

How many miles do you have on your car? I would strongly recommend that you consider changing it out if you have more than 60k miles. I thought my 3/08 built car would be fairly safe from excessive bearing wear, especially since it's one toward the end of production - you would have thought those engine builders would be experienced with putting these things together...Boy - was I wrong about that assumption! I think those engine builders got lethargic on the latter built motors, to be honest.

[Vanne]

No, but I've removed the oil divertor, and replaced with an always open unit. Bearing wise, it's probably and practically best to assume they are wear item, just like tires.. I'll pull mine at 50k intervals.

That constant pressure valve/spring, all it does is even out the irregular pressure dependant upon pump rpm. Very much like the accumulator we talked about before. i don't think changing that spring will net you any extra oil px, as that's derived from the pump turning at rpm.

If your looking at moving increased volume and thus px, you'll either need to increase the pumps revolutions, (read decrease the cog size on the pump) and or widen/increase the pump's volumetric effeciency. Or even easier, just get one of these from VAC.

https://store.vacmotorsports.com/mob...b32-p1033.aspx

You'll need to supply your own pump though..

[wyshyvanuk]

Thanks, again, gentlemen!!
Happily (I think), I completed the installation of the G-Power supercharger last night, at least to the extent that I can sneak out of the garage and drive slowly about the neighborhood. So this bearing/oil thing is about to get real.
I have about 46k miles on a 10/2007 build date. Second owner with no information on the first 40k miles.
That Constant Pressure Valve is the one that's screwed into the back if the block on the exhaust side, not the one that's internal to the oil pump. I'm still not 100% sure of what it does.
Vanne, is there any downside to installing that VAC pump?

[Vanne]

"Is there any downside to installing that VAC pump?"

well yeah, its 600 bucks pp, and you gotta send em your pump...

(just noticed your from Tucson, i spent 2 years there.. awesome joint.. Love Mt 'A' )

[wyshyvanuk]

Oh, yeah, the cost. Well, in for a penny, in for a pound ;~). Do you think that the upgraded pump, cost aside, is worthwhile? There will be no track time for this car, but I do, occasionally, hoon around the state.
Also, I'm pleased to report that we currently have Dubai's temperatures beat....but not for long.

[Vanne]

track time or not, i am under the impression that most wear probably happens at crank and/or non sufficient warm up before putting the loud pedal down. i wouldent bother, even under heavy spirited drives, the oem oil pump is more than able to provide enough positive px. The achilies heel isnt really the oil pump pressure, just the design of the bearings, and as such it comes with the tag being a consumable item.. Id chuck the extra cash on some supsension upgrades/oil changes.

Lol yeah, it got quite hot there.. I was based out of a little joint there called Marana, though lived in Tuc.

[wyshyvanuk]

Vanne, if you keep eliminating my expensive, time-consuming projects with fact-based advice, I'll need to start reading, or exercising or traveling. The horror....;~).
Projected temperature today = 112°F. Arrrhgghhh.