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).