Ok Rover Experts, here is a new problem for you to solve. Daughters Rover oil analysis just came back with VERY high aluminum content. Most everything else is as expected, except the fuel dilution lower than expected. Vehicle is used mostly going to and from school, 3 miles each way, not alot of time to reach operating temp. Most of my other vehicles always show high fuel dilution (due to the high percentage of operation time not at temperature is my theory). Oil has been in there a year but only about 3k miles in that time - oil looks good otherwise (viscosity in range for 15w40, other parameters look ok).

Engine idles at 25psi hot, runs 45 at 2500 psi. 180k miles.

So the question is where is the aluminum coming from, and is there anything I can do about it? Horizon/Polaris suggest piston metal??

1. Oil pump housing? pump wear would lead to low oil pressure though.
2. Engine bearings? There woudl be high levels of tin and copper.
3. There was an entry on an aircraft forum - valve guide has come loose in the head and is going up and down, wearing the head. Head gaskets did blow in the last year and were replaced.
4. Cam thrust surface? Wouldn't that lead to low oil pressure as well?
5. Valve spring seat in head? Not sure why that happen.

Oil analysis attached for your enjoyment.

 

What about rocker arm material? were those checked for wear when the heads were done?

 

Pretty sure those are stamped steel.

 

What engine are we discussing?

 

Rover v8 rocker arms are aluminum and the shafts are steel. There are aftermarket arms that are steel, but not stamped.

 

yep. all I've dealt with in a rover V8 are aluminum and shafts are steel. when he said that about stamped steel I thought I must be missing something since even the aftermarket steel ones aren't stamped.

I thought I had stumbled over to the SBC forum for a minute there.

 

the problem with using oil analysis is you need several to go by, one is just a baseline.
it's like having you cholesterol checked, you need a starting point to work from.

I have oil samples take on all my compressors over 5hp once a year, some compressors run more new than a new Range Rover, so you just don't wait until they die. but the first years are as i said are baselines, something to work from.

The high aluminium count could be caused by piston scuff, rocker arm or it could be normal for an aluminium block. they say it is high but i don't see where they say what the normal limits are.
oil racing threw unlined aluminum oil passages as 40 psi I would assume would show more aluminum than a steel block. what are they using for a comparison?

 

I'm not up on oil analysis so just getting in for the education.

One thing I noticed on the report is they think they are testing oil from a diesel engine and comparing to what? oil from other diesel engines? (does that matter?)

also they mentioned severe piston wear as a cause since pistons are aluminum, do they realize they are testing (comparing sample levels) from an aluminum block with many aluminum parts that's been sitting in an aluminum oil pan?

Another thing I noticed is they ask for the brand of oil to compare to averages.
"Please provide missing FLUID PRODUCT NAME to compare data to the correct standards."
So what are they comparing it to now not having the brand?
I would think that any lab analysis is only as good as the input data...garbage-in garbage-out...so with missing input data how could it be accurate?

A few other uneducated guesses:

If the oil pump had a small crack and shaving small amounts of aluminum couldn't the oil pressure still be decent?

and if using rotella diesel oil (I'm assuming rotella) with its cleaning detergents on an old engine, wouldn't it clean old deposits and sludge build up that has years of aluminum deposits in it and put it into the oil pan...skewing the analysis? if compared to a clean engine that has used the same detergent oil for it's entire life and has no old build up or deposits?

and if you stored detergent oil in a dirty aluminum container (oil pan) for a year (since last oil change) wouldn't it have higher amounts of aluminum than if stored in the same container for only a few months? especially in an oil pan that has years of old deposits? the detergents would have a year (since your last oil change) to dissolve the build up/deposits with embedded aluminum instead of the usual 2 or 3 months.

anyway, just some random thoughts... and as usual most of my thoughts are random!

 

Next time try blackstone labs. They give you a baseline from their database showing average wear compared to other users with the same engine.

my sample report from my M5
http://imgur.com/F740bMA

 

Sorry I have been away from the forum a few days. Thanks to the experts for reminding me of the aluminum rocker arms, that is probably the source, I will take the valve covers off within the next few weeks and report back.

To the other posters/questions:

1. Yes baselines are good and this is my first test on this engine, but the 180ppm is crazy high. Normal is less than 10ppm (see attached for my analysis from my LS1 Camaro all aluminum V-8, run much harder than the Rover), high readings for other aluminum engines are in the range of 20-30ppm. 180ppm is off the scale.

2. The are basing the analysis based on the diesel oil type because that is what I told them, I run the diesel version 15w40 to get the zinc additive package for flat tappet camshafts.