We have taken a Diesel engine lube oil sample and the analysis results show 16 ppm fo Aluminum (7 ppm in a brand new lube oil).
Any of the components in the lubricating system contain pure aluminum parts.

Where this aluminum is coming from?

Thanks in advance

Why would new oil contain 7 ppm Al ?
And how many hrs has the oil been used? And what about other elements?

In diesel engine oils,the aluminium can be coming from Engine blocks, pistons, blowers, Oil pump bushings, bearings,Cam bushings,Oil coolers etc...as a wear metal.

Have no idea why new oil would contain Al but we have seen a specific new oil which has about 10 ppm Al in the new oil. Otherwise Al would generally come from pistons in a diesel engine as a wearing part, some bearings, some blocks and part of dust with Si.

Hello everybody:
I really do not know why new oil contains Al. We have made some considerations and have found that the crankshaft thrust (axial) bearing has Aluminum among its components. We will take a look and we will see what happen.
The other components of this lube oil are: Si 20 ppm; Cr 2 ppm; Cu 7; Fe 7; Ca 17021; Ni 259; Lead 3; Tin 2 and Va 696 ppm.

Thanks

quote:

Originally posted by Catracho:
Hello everybody:
I really do not know why new oil contains Al. We have made some considerations and have found that the crankshaft thrust (axial) bearing has Aluminum among its components. We will take a look and we will see what happen.
The other components of this lube oil are: Si 20 ppm; Cr 2 ppm; Cu 7; Fe 7; Ca 17021; Ni 259; Lead 3; Tin 2 and Va 696 ppm.

Thanks

Is this a large diesel engine running HFO fuel? If so I would not worry about the Aluminium content, but more about the Vanadium and Nickel. They might indicate HFO (excess) in the lube oil. Check viscosity. (You then might be looking at blow-by during combustion.)

Hello everybody:

I am confused. In the first two weeks of March, some samples where taken and the analysis results are: Al= 8 ppm and 13 ppm; Va= 884 ppm and 893 ppm; Ni= 310 ppm and 327 ppm. For samples of the following two weeks, the results are: Al= 10 ppm and 15 ppm; Va= 768 ppm and 851 ppm; Ni= 278 ppm and 313 ppm. If the engines have had the same lube oil during the last months, how one can explain these changes?

These are medium speed Diesel engines, and the only action performed related with the lube oil is the top up and rarely, refreshment(sweetening).

I would expain those results the following:
- some variance of element content in the oil volume
- some variance in Vanadium and Nickel lines in ICP/RDE instrument in lab. Usually theese elements are calibrated in low values (ie. 10 ppm and 100 ppm). Therfore som variance will occur in higher values.

Anyhow, you do not experience any abnormal increase, so you should not wory. If you had seen the Al value reach 30-40-100 ppm I would worry..

What is the TBN and visc values?

Hi mr Hughes:

Thanks for your comments. The lube oil is Taro 50XL40, where 50 is the TBN. Actually, the oil has a TBN of 30 and a kinematic viscosity @40ºC of 150 cSt.