bearings

[jazbo]

I have an Aurora with the 4.0 V8 and an Impala with the 3800. I periodically send the oil in for analysis. Both cars get Mobil 1. The Aurora always comes back with very little dirt and very little of all the wear metals across the board - 3 tests now. It seems it will last forever. The 3800 comes back pretty good except the copper is pretty high. This time was 57 ppm in only 2200 miles. The dirt is low and the other wear metals are low as well.

The lab says that the copper is likely from the bearings, but was a little puzzled that the lead and tin were not elevated as well. They were 2 and 5 ppm respectively. Iron was 21 ppm - which they said was fine, but maybe is not super low for only 2200 miles. The dirt was only 11 ppm.

Are all bearings - northstar V8 or a 3800 pretty much made the same? Materials? Might there be a flaw in the bearing and it's just going to wear like this? Any thoughts or suggestions?? Maybe 3800's are different and this is typical?

[Scotty]

I am sure that bbobynski will have this nailed, I recall him discussing this once before. However, where do you send your oil to be analyzed, I am very interested in trying out the service, thanks, Mike

[jazbo]

Thank you very much.

Yeah, I'm a nerd that just "has to know". I've used a K&N filter, so I'm a little more interested in how things are. Anyway, on the 3800, the copper was high on an earlier test - not so with 3 tests on the northstar where every time it's great. I think they are picking up that something is going on with the 3800. However, you are probably right that it doesn't matter.

If there was a leak in the air box or duct or wherever and a lot of dirt was getting in the engine, it would probably show up in many ways. But if everything is functioning properly, I see your point that these tests may be pointless.

That's interesting and makes sense about the coolant in the oil. It would be hard to get a sample that would catch this.

Because I'm a nerd, I'll probably do one more and use a paper filter this time. I doubt anything will be different though. Maybe that'll be my last one. I've used Titan Laboratories

1380 Zuni Street, Denver Colorado 80204

800-848-4826 303-893-5273 Fax 303-607-9025

I got a couple of free tests (inadvertently) by doing my own oil change and getting the sample bottle from a local dealer. They sent it in with their test bottles and I would up getting the results for free. I even tried to pay. They caught on and would not give me any more lab bottles and pre-paid mailer boxes to the lab though. I guess I got hooked on having to know.