AirBusPilot

Looks really good. The engine had 10,700 miles when the sample was taken, 3700 miles on the sample. The car is not babied, but no track time (road race). Wear metals are lower than average, even after extending the oil use almost 20% further than universal averages. First oil change at 1500 miles, second at 7000 miles. Mobil 1 oil filter.

I believe the valve guides are iron, if so, it looks like I'm not having a problem with guide wear. Or any wear at all.

Timothy Barth

That is very interesting. How much do they charge to do that test?

AirBusPilot

$25. Worth it, IMO.

davekp78

Considering the mileage on the car, and on the oil sample, I'd expect the results you got even if you used dino oil.

AirBusPilot

I wouldn't. I know of no dino oil that meets (or even claims to meet) GM4178.

There's almost no documented information of when an LS7 is broken in (factual info like wear metal count). I've seen someone claim high wear metals still at 17k miles.

My LS3 car was still showing high wear metals at the same total mileage. The OLM didn't take into account new engine wear metals.

There is also almost no information on the OLM v. actual condition of the oil v. mileage. I now have a reference point. I can wait and change the oil at 5k miles miles. At the sample of oil taken at 3700 miles, the OLM was at 54%.

CyberGS

Sample was at 3700 miles, and then you went another 3300 on it, so the sample was taken from the oil that you ran 7000 miles? Are you going to get a test done of the 7K oil? edit - point of question is they were seeing viscosity break down at 3700 on that oil, so wondering how much degradation nearly doubling the miles on that oil did...

This is great info BTW! I have just over 1500 miles, and not easy miles, on my new GS and I intend to swap the oil out and get a sample done, so would be nice if you have your data on the LS3 to post as well (since you noted in your posts you saw higher wear metals in that engine)

AirBusPilot

No, this sample had 3700 miles on it, the engine had about 10.7k total miles. First oil change at 1500, 2nd at 7,000. I haven't changed the oil yet, but I will at 12k miles (5000 on the oil).

The LS3 oil sample had about 8k miles on it. I went by the OLM thinking that would work, but the wear metals were dramatically higher than this sample on the LS7. I had them run a TBN analysis on the LS3 oil at that time and the oil was in great shape, just lots of wear metal.

I'll probably do another oil sample when the engine gets to 30k miles, then probably every 20k miles thereafter.

CyberGS

thanks for the reply... so you do not track your car, anything like that and it appears you still would need to change your oil every 5K miles then? Hopefully I am not being dense here (likely ) but I think what I am understanding - based on the analysis they are suggesting you change your oil every 5K miles right?

Also based on your statement about metal particles in your LS3, I am definitely doing the oil in mine here this weekend at roughly 1500 miles, then probably do it again at 5000 (3500 on the next change), etc. Again, I am going to send for a sample set myself on my oil and get their recommendation, but based on what you are saying I am expecting to change the oil somewhat frequently here in the first 10K miles of ownership. I had planned to cut my filter open, but for $25 the oil analysis is definitely the way to go!

AirBusPilot

I could do another analysis at 5k and see what its doing, but I don't think I will, I'll just do 5k oil changes for now.

At 1500 miles you'll likely see a ton of wear metal since it's your first oil change and the motor is brand new.

TARANTULA

I just sent my sample today. Car has 5k still with factory oil will see what happens.