Oil Sampling

[dario]

I was shocked and surprised to see that one of the forum members had an M50 engine failure. This failure appears to have been a bottom end bearing failure.

clearly I do not know what the cause of it was, however my experience leads me to believe that it was unlikely to have been a sudden failure of the bearings (mains and big end) which would occur if the oil pump packed up, or the oil level went low for a period of sustained high RPM engine running but a progressive deterioration of the bearings over a period of time.

my company work on very large industrial diesel engines which because of the quantity of oil often have a sample taken for analysis rather than just change it out. this sampling can and does show trace elements of materials which are contaminating the lubrication oil. This provides advanced notice of bearing and piston ring failure and allow appropriate action to be taken.

I have attached a link of the company /report and wonder if this may be of use to the M/// member of the

http://www.wearcheck.com/services/testk ... stkit=MOB1

[Nik Rite]

Hi Dario, It certainly starts you thinking! The sampling method is very precise but probably not difficult. With some of these guys engines costing £10k for a rebuild it would be interesting to see what is wearing and when. I didn't look hard at the article but is it expensive for Jo Bloggs to have a sample analysed? Is it difficult to understand the information returned on the oil sample. Since the analysis company dont know what each component is made of , how do you know what component it is that is wearing, if you know what i mean. If the company tell you , say, there is unusually high quantities of say iron how do you know where thats coming from? Nik

[dario]

Hi Dario, It certainly starts you thinking! The sampling method is very precise but probably not difficult. With some of these guys engines costing £10k for a rebuild it would be interesting to see what is wearing and when. I didn't look hard at the article but is it expensive for Jo Bloggs to have a sample analysed? Is it difficult to understand the information returned on the oil sample. Since the analysis company dont know what each component is made of , how do you know what component it is that is wearing, if you know what i mean. If the company tell you , say, there is unusually high quantities of say iron how do you know where thats coming from? Nik

HI Nik, you have a point about where the wear metals are coming from. however if you look at the attached wear check report you will see the second row of information shows "elemental analysis and wear metal PPM"

this is a good guide to what is happening in the engine. within this report you will get a warning if something is slipping outside of what they would expect a standard oil sample to contain. the most appropriate way to do this is to regularly analyze the oil say just before the oil change. this will then allow a trend to be built up of the particulates in the oil. most certainly it looks like the oil could do with changing more often if the owner is swift driver surfing on a wave of revs.

this has to be better than facing up to the cost of repairing an M /// engine outside of warranty.

Dario

[stu]

Hi Dario

Having worked on large piston and gas turbines (aerospace) for a lot of years in a previous life, I'm glad to hear you can perform this type of analysis.

I also know the benefit of prevention rather than cure, which might be of great interest to the board members, and maybe even the wider BMW Car Club.

It's clearly very important to get the 'normal' parameters set up for various engine types (materials) with vaious mileages for the warning and action limits that owners should be aware of.

What sort of analysis could be provided without a starting database of samples? What sort of cost is involved?