First Oil Change (1 Viewer)

[damooji]

Sharing UOA, factory fill, '25 P+, around 1300 miles. Nothing surprising, seems norm for break-in.

 

[roaniecowpony]

In my oil analyses, I plan to look for bearing wear trends, fuel dilution, and water content. Fuel dilution and water content can be affected by my driving behavior, so I want to see if I'm short-tripping the car too frequently.

Specifically for bearing wear, I just want to know if I should be expecting impending doom and changing my plans for long trips. Plus, I'm nerdy and would love to experiment with oil viscosity and usage (towing, frequency of WOT, ambient temperature, remote starting in winter) to see if I can affect bearing wear with those kinds of changes so I can better understand the root cause of bearing failures in this engine.

While I believe having more data is powerful in decision making, the reality for me is that it won't change our driving habits. We're retired and my wife's GX will live mostly in the short trip lifestyle, with the occasional road trip. Unfortunately, it seems this 3.4 engine doesn't get decent fuel economy with towny driving, which tells me that fuel dilution will be high for her driving habits.

I had really planned to not do any maintenance on her GX and purchased a full maintenance plan, because I wrench extensively on my rock crawling jeep and my pickup to a lessor degree. But, it looks like I should do a few UOAs from break-in until it settles down, and see how bad the fuel dilution really is. I may be forced into doing OCIs between the scheduled maintenance plan. I just did a drain and fill, no filter change, at around 630 miles this past week. I plan on doing another around 1000 miles more. I'll likely UOA that drain. Dang. I guess I'm not getting ouf maintenance on her vehicle.

 

[cmfhsu]

For short-tripping, I'd planned to fix it by simply taking a 60 minute leisure drive with lots of WOT every month or two - no changes to my normal driving behavior. Should help both evaporate fuel & moisture as well as clean some carbon off the valves. I also want to make sure I'm not burning oil & replacing it with fuel.

Inevitably, I will buy 2 UOAs and never do it again, like I've done with every new car I've ever owned.

 

[cmfhsu]

That is a great video about why to change your oil in the first few hundred miles. I changed mine at 1100mi and was surprised at how dark it was. I’m glad I got the initial break in debris out. I wish I would have known about sending a sample out for analysis.
I noticed that there was silver crud on the dipstick when I’d wipe it off with a white paper towel, before changing the oil. If you haven’t already changed your oil, do you get silver crud on the towel when you wipe off your dipstick? Just pinch it between your fingers and see what you get.

Just noticed your question, Balsa.

I only have blue shop towels, but definitely zero metallic content and zero silver on my dipstick. Are you sure it isn't the milky-coffee looking stuff you get when you have moisture in your oil? Can you see milkshake on your oil cap?

I would think that if you can reproducibly see silver on your dipstick, there's so much metallic content in your engine that it would have failed already. It's kind of hard to replace the dipstick without accidentally scraping it on the tube - maybe that's what's happening? I have a scratch in my dipstick from accidentally scraping it putting it back into the tube.

 

[roaniecowpony]

For short-tripping, I'd planned to fix it by simply taking a 60 minute leisure drive with lots of WOT every month or two - no changes to my normal driving behavior. Should help both evaporate fuel & moisture as well as clean some carbon off the valves. I also want to make sure I'm not burning oil & replacing it with fuel.

Inevitably, I will buy 2 UOAs and never do it again, like I've done with every new car I've ever owned.

Some driving in high BMEP range of the engine is good for ring seating. Too many people think that babying an engine is good for it. Rings seal because cylinder pressure forces them against the bore and they wear in. When breaking in an airplane engine, I would run them hard and could actually see the cylinder head temps drop abruptly when the rings would get to the point where they were largely worn in. The transition of temperature occurred very fast, like just a minute or two. Wearing it in, however could take 10 to 30 minutes at high power, or sometimes repeated flights with high power.

 

[cmfhsu]

We're mega digressing now, but modern engines with tiny turbos are great for break in - boost really helps drive that cylinder pressure up and shove the rings against the cylinder walls.

I remember locking the car in fifth gear on my long drive home from picking it up and rolling into a 3/4 throttle pull. The revs spiked and I assumed the car was simply unlocking the torque converter as programmed, but now going back and doing the same thing, I realized I was laying into it before the transmission had learned the correct pressure needed to keep the torque converter locked. Oops - probably glazed up that torque converter clutch a bit.

I'm used to breaking in manual cars, so I've never had to contend with things like transmission adaptation.