Help understanding this oil sample needed...

My friend has piston slap in his LS1 and GM keeps saying its a spun bearing eventhough he always has very good oil pressure when the car is hot (45psi at 1200rpm).

Tin: 7ppm

Lead: 21ppm

Copper: 106ppm

Aluminum: 14ppm

Silicon: 49ppm

Iron: 51ppm

Chromium: 3ppm

Silver: 0ppm

Zinc: 950ppm

Magnesium: 21ppm

Nickel: 2ppm

Barium: 0ppm

Sodium: 9ppm

Calcium: 2000+ppm

Vandium: 0ppm

Phosperous: 795ppm

Molybdenum: 98ppm

Boron: 103ppm

Manganese: 215ppm

Also said mg per KG in brackets beside each measurement.

You may want to see if Patman can comment on it.

If it's a spun bearing he should get a new short block. So either way the problem is fixed.

If it's a spun bearing he should get a new short block. So either way the problem is fixed.


Wouldn't that be a lot more expensive than a straight rebuild?

I assumed this was under warrenty. If not your still going to have to spend the money eventually.

GM won't cover it because they say he hasn't been changing the oil. They say this because he didn't keep his oil receipts. He has about 30,000 miles on it.

If he really did change his oil I'd bitch up a storm to them. He could have changed his own oil for all they know, and not everyone keeps a damn log book of changing the oil. I change mine in my truck every 3,000 miles give or take a couple, end of story. I don't need a logsheet to remember that, lol.

Yikes! Something is definitely amiss! I would highly recommend he get in touch with Terry Dyson, who will help him interpret these results and pinpoint exactly what is wrong with his engine. He's been doing this for over 20 years and truly knows his stuff. Here is how to contact him:

http://www.bobistheoilguy.com/terry.html

The sample results should recommend any faults to look at. If lead etc is too high, they would recommend checking the bearings. High glycol and they would recommend checking the cooling system for leaking into the oil.

Trouble with those results is there's no reference as to what's acceptable.

106ppm of copper might be fine although I can't see why there should be any copper in the oil unless a bearing is going.

Main bearing are hard to diagnose since they don't knock. I found one in my engine last fall. It ran fine but oil pressure finally dropped to low at an idle for my liking. When I pulled the pan, there was bearing flakes everywhere. My lifter valley has screens and most of it was trapped up there.

One thing you might want to do. Pull the oil filter and cut it open. I usually put the filter in a vise and cut it open with a hammer and a putty knife so I don't get fillings from cutting with a hack saw. Take a section of filter material and squish it in the vise to force out the oil. Open up the material and look to see if there's any metal trapped in the paper. If you don't squish out the oil, it's harder to see small metal. Large metal parts show up real well even without squishing.

Inspecting the filter
Summit sells a nice large tubing cutter for this very purpose (examining the oil filter). Works just like a tubing cutter only on a larger scale :) Makes it simple. I do this every time I change the oil...
Link (http://store.summitracing.com/egnsearch.asp?N=4294925139+4294925137+4294854745)

Dealing with dealers
Tell your friend to begin bitching about this in a major way. They are simply trying to get out of doing the work on their dime. If he has a 36K warrenty, then they should fix this, no question about it. Tell him to let them know that they (the dealer) would have to prove that he DIDN'T change it (IE impossible) if it made it small claims court. Dealerships do this crap all the time. He might think about simply taking to a different dealership and see how they handle it. He might be suprised at how they handle it as opposed to the "shady" one...

Cu levels in the oil
That level of copper in the oil certainly points to wear as the source. Here's an interesting read on copper content in oils for deisels, and given the number of miles they go between changes, I would think that 100+ppm would be very bad in a auto engine (although it certainly could have come from some other source like as a base metal from an additive or something of the like)...
Link (http://www.noria.com/learning_center/category_article.asp?articleid=646&relatedbookgroup=OilAnalysis)

Good luck with it...
Dave C.

106ppm of copper might be fine although I can't see why there should be any copper in the oil unless a bearing is going.



High copper is completely normal for the LS1 though, at least during the first 30 or 40,000 miles. It comes from the cam bearings, and that level eventually comes down. My LS1 has 44k on it and my last couple of oil analysis results showed very low copper (2ppm on the last run, which was 6100 miles) It's not unusual to see 200 or even 300ppm of copper in a 5000 mile run on a low mileage LS1. The copper is harmless, you can see reports with very high copper but the rest of the wear metals are low.

FWIW, here was my last oil analysis. 6100 miles, using German Castrol 0w30 and a K&N oil filter. 43k on the engine at the time of the sample.


Iron 9
Lead 2
Aluminum 3
Copper 2
Chromium 0
Tin 0
Silver 0
Titanium 0
Nickel 0
Silicon 7
Potassium 2
Sodium 0
Boron 5
Barium 0
Calcium 2790
Magnesium 129
Moly 9
Phosphorus 782
Zinc 930
Fuel 0
Glycol 0
Water 0
Oxidation 63
Nitration 55
Viscosity 12.4 cst at 100c
TBN 4.22