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Oil thread with Lab Analyst

147K views 256 replies 33 participants last post by  Fluoxetine 
#1 · (Edited)
Hi,

Lab analyst on engine oil and engine internal condition.

Post your data.

Regards,
Anri
 

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#209 ·
Raymond,

My personal and final view for the E34 M5, E28 M5, E24 M6 these engines are old and and already tired from poor maintenance from previous owners. (I am excluding rebuild engines like your M88 or mine S38 3.6 and others)
What we are doing now with these oil labs is simply seeing how the engine continue to ware out in strange behavior from one to another.

I have given my personal opinion already regarding the oil change intervals specially in Europe were owners rule is early oil changes at 7500k km some push to 10.000km this is 2 times beyond what I like.

Also for very cold climates it is a must to perform early oil changes because the fact that the oil will see very serious temperature changes,
and this kills the oil in no time 1) Because the engine will enrich with fuel the cold start period 2) The temperature changes from -10C up to ~95C when engine warm up. That put together is shorting the life of the oil.

Regarding the oil choice we already discussed in previous post you and I agree their is no bad oil between several brand we have on the table.
The choice of using 10W-60 is great but leads me to a bit over kill for what you are using your car for! and also other people...Street driving.
The 10W-60 is not a cheap oil and to do oil changes at 3000k miles is a bit expensive unless you don't care for the money you spent then its fine.
For my personal daily driver E24M6 I start using 15W-40 Total Diesel TIR with hi Zink contain this oil is New to US market and I can get that thru SSF for just 3.50 a quart.
Oil changes are at 3000 miles and that is my thing.

Regarding your M88 cylinder head disaster I never understood at the time of your rebuild why you never ever got Used cyl head in a good condition ???!!! At that time to find cyl head for M88/3 was very easy, Raymond !!!
I never understood why you repaired this cyl head with zillion cracks....
Don't get me wrong the person who did the job may be done very clean and good job but in case of human Error that is Unacceptable in case of a failure, Raymond !!! At the time period of your rebuild at Ebay.de was flooded with M88 heads.....also UK junk yards who are dealing with BMW engine as well.
Its not like now days were the M88/S38 parts are slowly disappearing...
If you have a failure in this M88 cylinder head its all your bad choice of repairing your bad unit but lets think positive and continue to follow the oil lab.

Back to your post, I would not be concern about losing 100ml of coolant because may be your cap is old or some minor vapor occurs in the system. If your system is absolute perfect without any leaks then it will be a concern.
Knowing the BMW side plastic old tanks we can note some coolant leak on a cold start that will not be seen on the ground and little hear little there is how you are going to add.

I have been driving for about 5-7 years with 10W-60 started with Castrol moved to Liquil Mouly 10W-60 after I started to test some real data.
I think for daily driving and spirited street driving its not need for 10W-60. For the race track to use 10W-60 is a pice of mind.
I know an E46M3 shop owner tracks his car with Diesel oil 15W-40 for very long time on the race track, so far no problems.

Regards
Anri
 
#210 · (Edited)
Hi Anri,

I agree with almost everything you wrote, except:

Don't get me wrong the person who did the job may be done very clean and good job but in case of human Error that is Unacceptable in case of a failure, Raymond !!! At the time period of your rebuild at Ebay.de was flooded with M88 heads.....also UK junk yards who are dealing with BMW engine as well.
Its not like now days were the M88/S38 parts are slowly disappearing...
This was the case for S38B36 and S38B38 engines, but M88 and M88/3 parts were in 2009 already very rare. I used my entire network back to source parts across Europe. Some where found, but only complete engines that needed a rebuild anyways and since I wanted to maintain matching numbers and there was no warranty, this was not an option. In the end I traced a s/h M88/3 head from the previous business partner from member Euro-M5, but also that one needed serious work. I bought it as a reference and back-up plan, but that was it.

We discussed the matter with my engine-builder, who also has done quite a lot of Colombo V12's and he proposed this resolution. Was I happy with that? ..... No, but if BMW would have casted new M88/3 heads I certainly would have dropped another 4k Euro for a new head, however the only thing that BMW came up with was a new 356ED engine built with a S38B35 cylinder head. This road would mean the loss of the classic M88/3 appearance, which I was not prepared to accept.

Believe me that at the time I was very frustrated with BMW fur such poor spare parts policy and I even considered selling the M5's and making the move to a classic Mercedes Benz...... But after some cooling down time and with no other option available, we gave the two heads to my engine-builder who preferred to continue with my original head. The risks that you mention here are very true and I was very aware, but within the project's scope and timeline there was simply no other option, hence why I accepted the risk of relying to craftsmanship. :crying
 
#211 ·
Just a comment on forum activity - the real thing forums give us that Facebook doesnt is a searchable archive of mechanical advice and technical information, it is really important that we keep this going - as this thread demonstrates.

Even if Anri is right (and I suspect he is) that most of these oil analyses are simply about charting a late stage in life of engines that have already been through a great deal, with their future largely determined - it is still great to have so many analyses to compare to.

Let's keep posting !
 
#212 · (Edited)
The other two reports that I received in September are (1) GV44730 and (2) 3152643, both of which are non S38/M88, but in the interest of the day are worth sharing.

GV44730 is my daily driver, a late 2003 E39 530i Touring. This is the first report since the switch from Castrol TWS Motorsport 10W60 to Mobil1 New Life (NL) 0W40. This is more close to what BMW requires for the M54B30 engine (5W40 LL01) then the 10W60 grade that was used before that especially during the winter is a little too thick for the small trips in and around town. The subjective experiences with the Mobil1 NL 0W40 were very good. The running characteristics, especially in the cold have improved. However, the hard facts from the UOA give a different viewpoint.



With exception of aluminium and chromium, metal wear has increased throughout the entire line. The previous reports show a little elevated copper wear, but zero lead wear. With this first report on new Life 0W40, especially the lead has increased. Now, this still is in line with Blackstone’s Universal averages, but a steep increase from the GV44730’s own averages.



Now it is too early to draw conclusions (yet), especially on a single sample, but it appears that the engine wear has increased, which raises the following questions

Q1: Is it possible that a switch of oil type / brand, in this particular case from Castrol Edge Professional 10W60 to Mobil1 NL 0W40 can result in temporary elevated engine wear ?
Q2: If this is not the case, is it the LL01 approved oil itself that is at fault or just the longer service interval of little over 14000km (note #1) ?
Q3: Does the M54 also benefit from a higher viscosity engine oil, e.g. a 10W60 grade ?.

The answer to the first question that may be predicted by the most recent UOA report for GD55450. We observed a similar increase of engine-wear after switching from Castrol Edge Professional TWS to Mobil1 Extended Life (EL) 10W60 in the summer of 2012 (lab report F61476). However, according to the third UOA (report H02541) carried out in September 2015 this resolved completely. The next UOA for GV44730 that is scheduled around April 2016 will therefore be very interesting.

3152643 is our BMW E32 735i. Although it is against our nature, the historical data indicated that the tested oil had a service of almost 20000km. One would expect that the Total Base Number would be in the cellar by the, but Blackstone proves that this is not the case.



Because 3152643 has been in storage since late 2004, it may very well be the case that an oil service has been performed after the last documented service in 2002….. we always keep the bills and the work-orders as proof, but because 3152643 was business owned it may be that one bill was missed. This would not only have been more in line with the tested TBN, but also explains for the low amount of phosphorous that resembles that of the later blend of Castrol TWS Motorsport instead of the ‘Formula RS SAE 10W60 racing Syntec’. Although an exact estimation is impossible, it is likely that 3152643 has been spend an oil change somewhere in 2003 and that the real life of the tested oil is around 7000-8000 kilometres.

1: The elevated levels of aluminium and chromium probably comes from pistons and piston-rings.
2: The elevated levels of copper and lead points towards the bearings
3: The elevated level of iron could be the result from either item 1 or item 2.

I must admit that after the installation of a factory new cylinder head in 2002, the engine started to develop a slight audible tick that was traced to the bottom end. However, this only occurred when releasing the throttle. However, 3152643 was put in storage in 2004 and thus lowered the priority for resolving this. When the engine of 1018231 was rebuilt in 2009, we asked for a diagnosis, but the noise did not occur at the doctor’s office. In fact, this report is the first indication that there is an issue with the piston(s) and bearings.

Ignoring the fact that the cars (1) usage and (2) economic value does not justify for a full engine rebuild, this report may trigger some limited actions. The first action is to resolve the high amount of fuel found in the sample. We believe this is caused by the twenty-eight year old injectors that never have been serviced. The plan is to remove them during the winter for shipment to Bernd Prickartz, a renowned specialist in Linnich (Germany).

Another limited action that we could take is opening the oil-pan for an inspection of the con-rod bearings. Given the limited (material) cost their preventive replacement will then be a no brainer. If there is a causal connection to the suspected piston and piston-ring wear, the chromium and aluminium numbers will also drop. It may be possible that this also works the other way around, but we’ll see. A full rebuild is (and) will not be considered because of the earlier mentioned reasons and we know that M30’s can reach a very old age.

Notes:
1: This is still within the factory recommended service interval of 15000km.
2: Compared to most of its direct competitors, Mobil1 NL 0W40 has superior HTHS (3,8cp @150°C compared to the most of its direct competitors (0W40 and 5W40 grade).
 
#214 ·
Great update Raymond. Very interesting to observe the change in wear after you switched oil brand on the daily driver. I think it must be right that a change in oil has the potential to cause a step increase in wear - for example if the new oil did a less good job at coating key components causing more wear on startup ?

But I think it is also right that a longer service run could also be a significant factor. In previous posts on this thread we have discussed the rate of dropoff in oil, and me and other owners have observed that usage seems to increase significantly after a certain lifespan. So I'm sure it is plausible that wear increases after this lifespan too.

This inspires me to get on with my own oil changes. I have two to do at present. My E34 M5 (for which I posted an analysis a couple of months ago) is due an annual change - although mileage is low. And my new daily driver (Celica ST205 GT4) needs its maiden oil change under my ownership.
 
#217 ·
Hi,

Thanks for posting.

Your test looks good. The metal is a bit over what would be a ideal but nothing to worry, yet.

Why did you chose to use 20W-60 Viscosity ?
In Bulgaria the distances are short weather is bit on the colder side.
The 20W-60 is more race/endurance oil were the engine sees lots of rpm and for long time.

For what your car is use for 10W-60, 15w-40 or even 15w-50 would be ideal for your environment.

Regards
Anri
 
#218 ·
I drive my car spiritedly on weekends, my usual driving trips are 200-400 km long. I did 50 laps on a local track with this oil. If an oil is good for endurance driving, then it is good for my engine. Report confirms that.
For the winter season I changed to Castrol 10W-60, I will do 5000km and send for test to see if lower viscosity improves wear during cold engine starts, as this is currently my concern with the 20W-60.

Maybe I should start a thread for what I did to my car...
 
#220 · (Edited)
Sorry if this is the wrong thread for this.

I'm about to do a change on my S38B36 and given TWS 10w-60 has been discontinued (and is now priced here as if it were actual liquid gold, nearly A$20/Ltr..).

I'm considering two oils at present, both the factory spec'd viscosity 15w-40:

Liqui-Moly 15w-40 High Tech Touring (No idea on zinc, but should be 1000ppm or so given ACEA B4 I'm lead to believe...)
http://www.liqui-moly.de/liquimoly/produktdb.nsf/id/en_1095.html?OpenDocument&land=DE

The other, from an Australian company is the Penrite Semi-Synthetic 15w-40 (Full Zinc).
http://www.penriteoil.com.au/products.php?id_categ=1&id_viscosity=114&id_products=360

EDIT:
Could only see VANTAGE 15w-40 available in stores.. -> http://www.penriteoil.com.au/products.php?id_categ=1&id_viscosity=114&id_products=720
One of my local shops was running a 30% off deal, so grabbed a 10L tub, $5.80/Ltr, worse case the W124 260E can burn through it.

I will be sending off for analysis a sample of the current oil (Probably edge 10w-60 given the workshop who serviced it last) and again at regular intervals.

I have access to Liqui-Moly at good prices through a friend, so if the above 15w-40 or their 10w-40/10w-60 is suitable oil please let me know.

Also, given I don't rack up the km's on my M5, what's the recommended change interval by time?
 
#222 ·
Sorry if this is the wrong thread for this.

I'm about to do a change on my S38B36 and given TWS 10w-60 has been discontinued (and is now priced here as if it were actual liquid gold, nearly A$20/Ltr..).

I'm considering two oils at present, both the factory spec'd viscosity 15w-40:

Liqui-Moly 15w-40 High Tech Touring (No idea on zinc, but should be 1000ppm or so given ACEA B4 I'm lead to believe...)
http://www.liqui-moly.de/liquimoly/produktdb.nsf/id/en_1095.html?OpenDocument&land=DE

The other, from an Australian company is the Penrite Semi-Synthetic 15w-40 (Full Zinc).
SEMI SYNTHETIC 15W-40 (Semi Syn.)

EDIT:
Could only see VANTAGE 15w-40 available in stores.. -> VANTAGE SEMI SYNTHETIC 15W-40
One of my local shops was running a 30% off deal, so grabbed a 10L tub, $5.80/Ltr, worse case the W124 260E can burn through it.

I will be sending off for analysis a sample of the current oil (Probably edge 10w-60 given the workshop who serviced it last) and again at regular intervals.

I have access to Liqui-Moly at good prices through a friend, so if the above 15w-40 or their 10w-40/10w-60 is suitable oil please let me know.

Also, given I don't rack up the km's on my M5, what's the recommended change interval by time?
I quite like Penrite myself. I was using Shell 15w50 semi synth for ages, but they recently changed formula and the zinc dropped from 1200 to something ridiculously low (i forget exactly).. so I did some research and currently In my M5 I'm using Penrite HPR-10 which is a fully synthetic 10w50. Also in their "full zinc" range. They have a good techncial bulletin on ZDDP on their site. I try to buy it in 20L bulk when on sale so it ends up pretty cheap.

In my wife's E46 I'm using HPR-5 which is actually approved by BMW as an LL-01 oil - there's a copy of the approval letter on their website. Between that and the fact that they have heaps of technical info on their site, it seems to me like a good "enthusiast" brand - and it's Australian so you can get it everywhere...
 
#221 ·
You wont be sorry that the Castrol 10w60 is our of range, as this thread contains some quite convincing evidence that the ZDDP is too low for these cars. I don't know about those oils you list but there's lots of enthusiasm on this forum for Mobil Long Life 10w50, Fuchs Pro R 15w 50 and Motul 15w50 IIRC. But I'm sure the most important thing is clean oil and regular changes. I try and do most cars annually but Raymond posted some convincing research that led me to conclude I could drop down to every 2-3 years on my E30 M3 which has the Mobil 10w60 and hardly does any miles.


So if you don't know how old the oil is, or if its the Castrol then I would change it out asap, and get the new oil tested after (say) 1-2k miles.
 
#223 · (Edited)
I have to admit that I didn't share much content in the past few months; this is partially explained by a very busy work-agenda, but also because I took on two car-related projects that have no relevance with an E34 M5, albeit this changed due to the course of the E32 735i project, of which I shared an UOA last year.



We had the plan to perform an inspection II and a Bernd Prickartz overhaul of the injectors for this particular car (3152643), but when inspecting the camshaft sprocket, we observed some wear that ultimately opened the typical ‘tin-can of worms’.



Originally, we planned for a replacement of the camshaft sprocket only, but when checking the timing, we observed that the crankshaft was a bit off as well.



At this stage, we reconsidered the scope of this project and ultimately decided to replace the entire timing chain and associated parts. I have to admit that from an economic point of view, such a surgery doesn’t make sense on a 28 year old non ///M car, but from an educational perspective, this project can yield some much appreciated new insights and experiences. In addition, the M30B35 shares basic design elements with the S38B3x engine including the use of the same oil-pump, which for these engines is a ‘mission critical’ component because there is no redundancy, hence the oil pump is a ‘single point of failure’. Later more on this, but given that the replacement of the entire distribution is a huge extension of the original scope (inspection II), I was forced to postpone the scheduled work on my own E34S M5 (BK02837). I won’t go into detail about the replacement and failure mode analysis of the timing-chain and sprocket (can do a write-up on that if there is some interest from our members), but we completed that part of the project by mid-January. This comprehended the replacement of:

• Crankshaft sprocket
• Plastic chain guide
• Oil pump chain
• Oil pump chain tensioner
• Timing chain tensioner Rail
• Timing chain
• Seals of crankshaft and lower timing-case
• New camshaft sprocket
• New chain tensioner piston, spring and plug.



The synergies with the S38B3x start with the oil-pump. Being eager to learn, I disassembled this part into individual pieces for additional investigation.



Those with a little more knowledge of these Eaton-type pumps, will probably miss the piston of the low pressure relieve valve on the picture above. This should be an easily to remove part, yet on this pump it had too much inside resistance to drive it out. For the rest, the inner parts looked fine; granted, the pumps rotors showed some wear, but bear in mind that the pump is fed from an unfiltered oil-supply in the sump, so it mangles all dirt and wear elements that are not blocked by the filters protection screen in the input-nozzle.



We did consider replacement of the entire oil-pump, but at the time of this project, it was not available as a new part. Since no lead-time was given, I was reluctant to damage the cylinder by forcing it out. In order to learn more, I asked help from a fellow countryman, Ivo Christov, who had a high mileage M30B30 engine lying around. We agreed that this is an interesting study object, so Ivo send it to me soon after. We disassembled it and to no surprise, the piton of the low pressure relieve valve dropped out by itself.



In addition, the rotor’s coming from the pump from Ivo showed much more wear than the pump from 3152643, which is logical because Ivo stated that the despite the mileage of the original (M30B30) is not verifiable, it at least covered 300000 kilometres. This matches with the wear-pattern found on the rotor’s.



Basically, we can learn two things here:

1. If you doubt the mileage on the odo-meter of your car, just open the oil-pump and ‘read’ its wear.
2. The wear-pattern found on the rotor’s of 3152643 oil-pump do NOT explain for the level of wear elements reported by Blackstone in report H02539.

Coincidentally, the piston of the original pump of 3152643 dropped out simultaneously when inspecting and analysing the pump from that M30B30 engine.



Simultaneously, some debris fell from its cylinder.



I don’t know why the piston suddenly released, but these observations prove some non-conformance to the original design, which was confirmed when we had the front assembly casing cleaned and inspected by a professional who stated that the cylinder contained a ridge that prevented the free movement of the piston.



The hypothesis is that because the low-pressure relieve valve didn't move freely inside its cylinder, the oil pressure didn't regulate properly anymore resulting that the oil pressure does not correlate linearly with the increase or decline of the engine speed. As a result, the supply of oil towards the oil-filter does not have a constant velocity anymore resulting in highly stressed parts to receive not enough lubrication. Typically, con-rod bearings and camshafts are the first to suffer.



Because new pumps are not available, we decided to rebuild the existing pump of 3152643. The cylinder of the low pressure relieve valve was slightly machined and honed again, which restored the pistons movability. In addition, we installed factory new rotors and seals which should be more than enough for an M30B35.



For an S38B3x I would prefer a new oil-pump though, so I am glad not to have been confronted with this dilemma with my E34S M5. For a M30B35, I see this as an experiment that makes sense in every respect, but most importantly, we learn from this. From this point, we could have decided to reinstall the oil-pump, but given the lessons that we learnt, I decided to replace the con-rod bearings as well. Blackstone already reported high amounts of lead, copper and tin in the last sample, so it wasn't unexpected that the upper-halves of the bearings were completely worn (at least from my perspective)



The following picture shows the old upper-halve shells of cylinders #3 and #4 ad compares this with a factory new bearing sourced from my BMW dealer. These bearings are of the so-called Tri-metal type. The first layer is a soft and thin lead-based overlay, the second layer is a nickel barrier whilst the third layer is a lead/copper and tin alloy. Clearly visible is that the wear has reached the last layer before the steel substrate; whilst one may argue how much life is left in these bearings, chances are that if left unattended, the engine will blow a rod at some point in the future.



So we replaced them all, which gave an added benefit as well; practical hands-on experience if I ever need to do this on an S38B3x.



Generally, this task is not so difficult, but one needs to be careful and methodical. The main risk is an accidental re installation of the lower-con-rod halves in the wrong position or direction. If that occurs, the engine will blow eventually because these parts are manufactured to precise and matching tolerances.



Although we didn’t plan to go this far, everything that we have observed and found can be correlated to the oil analysis of Blackstone with as root cause, an oil pump that didn’t work as it should. Since this part is shared with the S38B3x, some of the E34 M5 population will undoubtedly have the same issues. I hope that the lifecycle status of the short oil pump is soon back to available again, because I want to secure one for my E34S M5 that also has some (minor) bearing wear that needs to be addressed.
 
#225 ·
Agreed, a most excellent post.

I've ordered a kit from a local UOA company here in Aus and was contemplating testing my gearbox oil too.. When the oil was last changed a little chunk of a gear tooth was found on the magnet and although I have receipts for a rebuild <5k km's ago, the shifter has always vibrated in 4th.
 
#226 ·
M60B40 oil change

Just changed the oil in the 540/5 and it came out black and smelly after 2,500kms

Shell Helix HX5 20W-50

Shell Helix HX5 20W-50 | Shell Global

I changed the oil as there was a fair bit of valve train noise on start up (30 deg C outside) with the engine cold which tells me the oil is getting marginal.

I swapped a junkyard M60B40 into my 530 and did the first oil change at 250kms (also black) so I'm hoping this is all from flushing out crud from a junkyard engine that could have been sitting for years.

I bought some Castrol TWS 10/60 today as it was the only half decent oil the shop had

I was tempted to use Mobil 1 0W-50 but it said racing use only (any tips on this ?)
 
#228 ·
Previously i use Teboil 10w-60, now NLA. Last summer i use Kendall 15w-40, also now NLA.

This years first drive outside temp was +0.5C. Last week i drove M5, max outside temp was +14C, average maybe +7C. I drive quite moderately, maybe once a year oil temp exceed +80C. This makes me wonder, should next oil be 5w-40/50? Maybe Mobil 5w-50, local M mechanics recommend that for S85.
 
#229 · (Edited)
Gents,

Following is a UAO from Blackstone. Oil is Brad Penn 20w50 semi-synthetic with 2450 miles of use. Of note is the high TBN of 5.9, and superb phosphorous (1396) and zinc (1604) measurements.

This was my first use of Brad Penn since owning the car. I am running my usual Valvoline 20w50 as I wanted to see results before deciding whether or not to continue with the Brad Penn semi-synthetic. Based on the Blackstone report it seems like a good reason to switch. What do you think?

Greg

P.S. Cannot get the Blackstone report to attach. If someone can tell me how I will gladly post it. I have attached reports in the past but I suppose something got "improved" so now I cannot figure it out!
 

Attachments

#230 ·
This was my first use of Brad Penn since owning the car. I am running my usual Valvoline 20w50 as I wanted to see results before deciding whether or not to continue with the Brad Penn semi-synthetic. Based on the Blackstone report it seems like a good reason to switch. What do you think?
Brad Penn has always been on my radar as it has excellent specifications and your results proof that it has excellent performance as well.

The only reason why I am not using it because I am concerned about the impact to the seals and gaskets when reverting back from synthetics to mineral, but is that a fact?
 
#232 ·
I did have the same concern about the potential to cause seals to leak. I have not noticed an increase in leakage from the original pan seal. It is described as a semi-synthetic. Not sure exactly what this means concerning the formulation. I plan to use Brad Penn again on the next change and for continuity I will service at the same mileage and get another Blackstone report to help make the best comparison to Valvoline.
 
#231 ·
I did have the same concern about the potential to cause seals to leak. I have not noticed an increase in leakage from the original pan seal. It is described as a semi-synthetic. Not sure exactly what this means concerning the formulation. I plan to use Brad Penn again on the next change and for continuity I will service at the same mileage and get another Blackstone report to help make the best comparison to Valvoline.
 
#234 ·
Latest analysis.

This makes a comparison between Valvoline VR-1 non-synthetic 20W-50 and Brad Penn semi-synthetic 20W-50 oils.

Noted in the report is the increase in iron which is likely due to several hard runs at sustained 5,000-6,500 RPM to blow off carbon.

Between the two oils, a point of interest is the flash point with the Brad Penn being below the desired value of greater than 385 F. The magnesium level is also quite elevated for Brad Penn. Other than these two measurements, it appears the Brad Penn has more favorable numbers, especially in the ZDDP department.

Thoughts?
 

Attachments

#235 ·
The last documented UOA of my E34S M5 was performed in September 2015 at 191568km. This UOA already demonstrated elevated wear levels of copper, iron and lead, which pointed towards bearing wear.



Originally, it was planned to replace the conrod bearings in the winter of 2015/2016, however two other car related projects came in between due to which this was postponed to the winter of 2016 and 2017. In the past few months, we took on this project and replaced not only the conrod bearings, but (purely as a preventive measure) the oil pump as well.



When performing the engine rebuild of the M88/3 engine of my E28S M5, I paid less than 10 Euro for a single bearing shell. However that was in 2009. Nowadays in 2017, their retail price has more than tripled.



After some time being out of stock, BMW supplies the ‘short-type’ oil pump again, however these retail at over 500 Euro ex VAT nowadays, but bear in mind that this is a mission-critical part and a single point of failure as well so from that point of view, it is imperative to replace the old pump.



After removing the sump, the oil pump and the crankshaft became visible to the full extent for the first time in twenty-seven years. As can be seen, the bottom end has that nice brown varnish colour; the engine is completely free of insoluble and/or sludge, which is a clear testimony if regular and short term oil changes with high quality engine oil, at least during my watch (since April 1999).



From the historical documentation, it appears as if BK02837 was not given frequent oil changes during its first four years. This is however unlikely as she was then in the inventory of a BMW main service agent in Switzerland and not registered for the first time until June 1994. Given this status, it is very unlikely that in between the first service by Roseg in Pontresina and the first delivery in 1994, no oil changes were performed.



Even though some wear was expected after 195655 kilometres, the extend of which cannot be determined (and documented) without performing a visual inspection. If one takes a closer look to some of them, spot wear down to the steel substrate can be seen



The journals for the conrod of cylinders #1 and #3 showed some scoring marks. Fortunately, the scoring could not be felt and a light polish made them disappear.



Upon disassembly of the original oil-pump, only mild level of wear to its moving parts was observed. Based on its condition, it was perfectly defendable to reuse the old pump, however (1) from a risk management perspective and (2) the current market developments for E34S M5’s in good to excellent condition maintaining the old pump would have been the wrong decision, so it had to be replaced.



The outer rotor showed some scoring, which is normal for these (eaton) type of oil pumps because te pump is situated in between the sump and the filter and thus is subject to unfiltered oil from te sump and thus prone to elements of engine wear and dirt.



The short summary is that any well maintained S38B36 can suffer from conrod bearing wear. In my particular case, I think the engine would have lasted no more than 10k kilometres without dropping a rod. Granted, this particular engine saw some appropriate use during the 94016 kilometres that I have added since April 1999. Using a different type of oil would certainly not have delayed the bearing wear. On the contrary, using a low-weight oil would only have accelerated the bearing wear during the more stressful driving conditions (at least 50% of my kilometres).
 
#237 ·
You got stock size bearings and did not measure?
I did actually, but demonstrating the process (how to) is not the intention of my contribution, which was merely aimed to scientifically proove the usefullness of Used Oil Analysis as an early detection method for critical bearing wear.
 
#238 ·
Hi All,

I've got my first sample being tested at the moment but had a phone call today citing that the flash point test had revealed >5% petrol dilution in my oil.

Ever since getting the car back from having the MAF replaced and vac lines replaced it has not run 100%, performance is down and I'm wondering whether the above is a result of over fueling. It certainly seems to have a small vac leak and small stumble at idle.

I'll post the full results when I get them for your advice.

Cheers
 
#239 · (Edited)
Ok, got the report:

Oil:
PENTRITE HPR10
Visc@40c: 131
Visc@100c: 19
TBN: 7.5

Report:
Wear Metals ppm
lead: 6
iron: 12
aluminium: 2
copper: 2
chromium 1
tin: 1
nickel: 0

Contaminents ppm
silicon: 13
sodium: 1

Oil Additives ppm
magnesium: 190
zinc: 920
molybdenum: 47
calcium: 2255
phosphorous: 789
boron: 17

Infra Red
TBN: 6.80
soot: 3
glycol%: 0
Fuel dilution: 3%
water: 0
oxidation: 13
nitration: 9
sulphation: 18

Physical Tests:
water%: 0
PQ-90 mg/ltr: 1
visc@100c: 15.85
visc@40c 97.48

Comments:
3% Fuel Dilution detected, please check fuel delivery system.


This 3000kms has seen significant idling in peak traffic as well as a number of short trips.

I am going to change the oil to Penrite HPR15-60, a full synthetic with full zinc additive package.

They are recommending an additive called Nanolub WS2. Anyone heard of this one?

Company that did the oil analysis is Techenomics
 
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