Oil results on the 91-S10 not so good...

[BIG BLUE]

This sample was the first I've sent since I bought this truck with 185,000 miles on it (now has 188,000+).  It's a 91 S-10 with the 4.3L(Z)code engine.  This thing has had an oil leak from day one and recently it's been showing signs of white sludge on the dipstick end.  So, I figured why not send off a sample just to see what the properties were.

 

Here is what Blackstone wrote in the summary: "BIG BLUE: Wear was poor in this sample, the metals from bearing inserts up near caution levels.  Iron, from steel parts, read quite high as well.  Silicon was high and may show abrasive dirt in the oil, but it could also come from coolant (inhibitors are silicone-based), which we suspect is getting into your oil.  Though we found no elemdnts common to ethylene glycol, nor any moisture, the oil's additives show moisture damage.  There are types of coolants that leave no elements in the oil we can detect.  Suggest having you cooling system pressure checked."  end quote.

 

Well, as you can see this engine with 188,000 miles is not the best on the block according to this report.  Listed below are the elements in ppm if anyone is interested.  First value is my sample, second is average (mine/avg)

 

Aluminum 16/6

Chromium 3/2

Iron 269/48

Copper 57/7

Lead 30/15

Tin 0/3

 

Moybedenum 23/47

Nickel 1/1

Manganese 2/1

Silver 0/0

Titanium 0/0

Vanadium 0/0

 

Boron 3/20

Silicon 21/10

Soduim 6/25

 

Calcium 1705/1140

Magnesium 44/470

Phosphorus 698/838

Zinc 765/992

Barium 0/10

 

Those are the values.  As you can see the ones that really stick out are the high Iron 269 vs 48 for normal, high copper 57 vs 7, high Lead 30 vs 15 and the high Silicon content of 21ppm vs 10ppm average.

 

I guess I didn't expect great results and I'm changing oil every 2000 miles at this point.  Previous owner must not have done much in the way of regular changes.  All I can do is keep an eye on the levels an hope it last through till spring when I get a new one.

 

Regards,

BIG BLUE

[TheScaryGuy]

Ouch, How much was it to have your oil tested?  And how did you do it?  Just a sample from a previous oil change?

[BIG BLUE]

I use Blackstone labs, have been sending out for analysis on my trucks for over a year now.  They send you a sample kit and instructions.  Essentially, you pop the drain plug and take a sample mid-stream while the oil is draining, in the bottle they provide (about 8oz or so).  Test results are back in about 1 week and runs about 18 bucks.

 

I figure that's only about $6 a month to keep an eye on what's going on.  On my newer vehicles I send a sample about every other change.  Just sent a sample of the rear diffy fluid from my 97 Sub to see if there was any unusual wear properties in the R/P.   Results came back way better than normal for that one.

 

You can go to www.blackstone-labs.com or call them for a sample kit which is free.  Only costs to have the oil tested and runs less than $2 to mail it back to them.  

 

Regards,

BIG BLUE

[CMNTMXR81]

Did the oil have a "milk shake" like look to it?  IF so, that'd indicate a coolant/head gasket leak.

 

Although you seem to have quite a bit of cautionary data, I take these oil analysis's with a grain of salt.

 

I use Titan Labs to test my oil on my fleet of vehicles and I've questioned their findings twice.

 

1) With the Camaro, on the second oil change after I built the engine, they came back with a silicon count too high and it was something "critical" I needed to fix.  How could this be?  I just rebuilt the engine 2,500 miles before hand!

 

2) On the Silverado, on the third oil change, at 3,500 miles I submitted an oil sample from it.  It too came back with a Silicon count too high  and was something "critical" that I needed to fix.  How?  It's a brand new truck/truck enginen!  On top of which they said dirt had entered the sample.  How?  The bottle was inserted into the draining oil stream and then sealed.

[BIG BLUE]

CMNTMXR81,

 

Yeah, I agree with you mostly.  I don't take these samples as gospel and don't change anything drastically based on results.  I mostly do it for kicks and to keep a record of how the engine/tranny/diffy fluids are holding up during the intervals.

 

Funny story on the Silicon content, I once sent a sample in on my 97 Sub after doing some heavy duty towing and off-roading, I then changed the air filter with a K&N drop-in and the next results indicated "silicon values were much better than the previous sample, and we would suspect it will continue to decline."

 

With the S-10, I suspected coolant the first time I saw the dipstick and oil cap.  Thing is, I'm not losing any coolant in 2000 miles or so, but need to do a compression/pressure check anyway.  Oh well, for less than $20, it gives some good info and is one more record to show proper maintainence for resale ;)

 

Regards,

BIG BLUE

[Joel]

I've ran several tests using blackstone and never had the silicon to high problem. However, it took far longer than a week for them to have results. More like 3-4 weeks although that could be from the stinking mail going from seattle to colorado, its up hill ;)

 

Joel