Can a GDI engine blacken oil in just 25 miles? (See pics)

The drain plug and filter are under a swing-down shield so I can't see or get to them to mark without a lot of work, plus it's 28° here. After bringing this to their attention I'm sure they will change it this time. The oil on the dipstick before the oil change was dark, as was the sample from the last oil change, but they were after 5,000 miles. I doubt that a quart of residual oil would have darkened the 5.4 quart sump that much, but who knows.

I believe this is a reputable dealer. I have been using them for six years and have been very satisfied with their work. The place is clean as a whistle, has eight lifts, and a large window where one can observe their work. I was too busy watching my wife drool over the 2025 yellow twin turbo Z on the floor to pay attention to what they were doing. Not sure what went wrong here, but I'll have them change the oil again tomorrow, will watch through the window, and pull another sample when I get home.
We have a lot of good dealers here like you stated, but they’re employees I would not trust with anything, I’ve had friends that had engines locked up at Walmart. They did not put no oil in the engine, I’ve saw them leave dipsticks laying on top of the engine with the hood closed driving down the road, I’ve seen the oil plugs left off on top of the engine.
 
I get free oil changes from my dealer for my 2019 Altima, which has a PR25DD GDI engine. After getting the oil changed yesterday, I drove 25 miles home and checked the dipstick. To my surprise the oil appeared black, so I pumped some out through the dipstick pipe and it is super dark, looks black in the bottle but very deep red in thin film, sort of like Coca Cola. I pulled two more 8 ounce samples just to be sure everything was flushed and it is just as dark. Even with a bright flashlight behind my sample, no light is visible through it.

I called the dealer and asked them to check with the mechanic who did the oil change to see if he may have forgotten to change the oil as I had other work done as well. The mechanic distinctly remembered changing the oil and filter, so I asked them to check their bulk tank. They sent me a photo of a sample from the bulk tank and it is golden. The dealer offered to change the oil again, which I plan to do.

The oil is a 0W-20 which they tell me is a full synthetic from Mobil, although the paperwork shows it as Nissan Genuine Oil (could be both). I did an 5,000 mile UOA on the last change at 50,000 miles, and while about 10% lighter than expected in additives and viscosity, it was still reasonably consistent with API SPs oils and the wear metals were excellent.

I know GDI engines generate some soot, but is it possible for a GDI engine to blacken the oil this much in just 25 miles of highway driving?

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My question is, did you take the car solely for the purpose of a free oil change? And this is the result? If so, is the free oil change really worth it when you have to drive 25 miles each way for subpar service?
 
I’ve saw your UOA on that engine since I have the same, just a few yrs newer. Looked good! I’m not up to snuff on Nissans GDI but if I understand correctly, they use some sort of port/GDI injection so fuel dilution isn’t as crazy as what you’d see on some other makes. I’m sure the oil is still fine, even if they didn’t change it. I’d still drive it into the service advisor and pull the dipstick so they can see it. I still will (probably) never run the full OLM on my 21 or 24. The 18 says 5k, and I’m just fine with that. Short tripping or not.
 
My question is, did you take the car solely for the purpose of a free oil change? And this is the result? If so, is the free oil change really worth it when you have to drive 25 miles each way for subpar service?
I brought the car in for rear brake pads replacement, brake fluid change, tire rotation, oil & filter change, and general routine inspection. At 74 I have pretty much hung up my wrench for dirty or unpleasant car repairs, although I still change oil & filters for our other two vehicles which have easier access. Even when just getting the oil change and tire rotation every 5,000 miles, it is not a separate trip as we frequently go to Christiansburg for other reasons and combine the trips.
 
When things like this happen, I always wonder, is it intentional or did they just forget? How do you forget though? I can see forgetting to put oil back in the engine, which would be catastrophic. But to not change it?
 
Remember this, it’s your car your expensive investment, you’re allowing complete strangers to work on your automobile
Not for me! me and my mechanic do a lot of work here and it’s done right fix right
 
I highly doubt that oil was changed. That said, did they fill it with oil from a jug or from a bulk tank? Someone in the oil group on Facebook posted two VOAs of ACDelco 5W-30, one from the jug and one from the dealer's bulk tank. The results were very different in particle counts with the bulk oil being substantially dirtier. It was also observed to be quite a bit darker from the bulk tank though TBN and oxidation was the same within MoE.

Jug ISO code: 16 / 14 / 11
Bulk ISO code: 21 / 19 / 16

Jug
>4: 610
>6: 88
>10: 23
>14: 11
>21: 5

Bulk
>4: 12,286
>6: 3,260
>10: 888
>14: 384
>21: 133
 
I get free oil changes from my dealer for my 2019 Altima, which has a PR25DD GDI engine. After getting the oil changed yesterday, I drove 25 miles home and checked the dipstick. To my surprise the oil appeared black, so I pumped some out through the dipstick pipe and it is super dark, looks black in the bottle but very deep red in thin film, sort of like Coca Cola. I pulled two more 8 ounce samples just to be sure everything was flushed and it is just as dark. Even with a bright flashlight behind my sample, no light is visible through it.

I went back and reread your post, and I'll emphasize the above.

You have THREE samples of oil with a supposed 25 miles on it. GET A UOA!
If that oil was truly not changed, you'll have WAY more than 25 miles of wear metals, Si, TBN depletion, soot/insolubles, etc.
Visual samples are subjective. UOAs are objective.
Get the data and have proof one way or another. Why guess when you can know for sure?
 
Get it changed or do it yourself . I had an incident like yours with the oil filter not being changed by the service center at a major dealership . Let it slide due to the oil being changed and did it myself shortly after . I wouldn't let the oil stay in the car as others have stated . Better to be safe than sorry .
 
So I had the dealer change the oil again yesterday and this time I watched. I brought in the black oil sample from the first change and my advisor was very surprised and said that’s not good. He then took the sample into the shop and conferred with two mechanics and a manager. They all appeared surprised and concerned, not knowing that I was watching from the viewing window.

They then gave the car to a different mechanic for the second oil change. I watched and he definitely changed the oil, draining it for about 5-10 minutes. I would have drained longer, but that should have gotten out the vast majority of the hot oil.

I then drove one mile to a Walmart and pulled the dipstick. The oil was pale and barely visible on the stick. I dabbed some on a white napkin, and after spreading it was very pale. This was definitely fresh oil.

I then drove the same 25 mile route home, and sampled the new oil today (see photos below). To my surprise the new oil was quite dark after just 25 miles, but not as dark and the last sample.

Viewing the two samples in daylight they both looked black and identical (first photo), but the difference can be clearly seen when shining a flashlight through the same diameter bottles. The second photo has the light behind the first oil sample and no light shows through. The third photo shows the light behind the second sample from today – much darker than fresh oil, but not as dark as the first when illuminated.

Given that the oil does indeed turn quite dark after only 25 miles of driving, I cannot positively conclude that the dealer did not change the oil on the first go around. It is possible that they did change it but didn’t let it drain long enough, giving a much darker sample, especially since the residual oil had 5,000 miles on it. It is also possible that the mechanic was so occupied with the 2 ½ hours of work he did on the car during the first change that he just forgot to change the oil, or that the dealer did not communicate well with him. Either scenario is possible. I will send the first sample out for a UOA to see if there are significant wear metals, but this may also be inconclusive as the UOA I did after the last 5,000 mile sample showed very little wear metals.

I doubt very much that either the mechanic or the dealer purposely skipped the first oil change. The mechanic is an employee and has nothing to gain from that, and the dealer has a lot to lose if such a practice was revealed to corporate or the press. This is not a small private shop where the profit quietly falls to the owner’s pocket – this dealer has no incentive to save a few dollars at such a risk, especially with a viewing window and lots of people in the huge shop.

In any case I am satisfied that I have fresh oil in the sump, and learned that this engine does darken oil rapidly. As for the dealer, they have always been straight with me and did good work. Even if they did do an inadequate job on the first oil change, every dog gets one free bite, so going forward I will trust, but verify!

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YES! my pos hyundai tgdi is as dark as any diesel in a couple hundred miles. I got upset with it when I first bought it. Did a conventional oci and 3 days later (150 miles) dumped it. Nice synthetic back in. Within a week black oil. Just move up one weight for the gasoline contamination and do 3k mile oci, Maybe yours won't blow up like mine did.
I get free oil changes from my dealer for my 2019 Altima, which has a PR25DD GDI engine. After getting the oil changed yesterday, I drove 25 miles home and checked the dipstick. To my surprise the oil appeared black, so I pumped some out through the dipstick pipe and it is super dark, looks black in the bottle but very deep red in thin film, sort of like Coca Cola. I pulled two more 8 ounce samples just to be sure everything was flushed and it is just as dark. Even with a bright flashlight behind my sample, no light is visible through it.

I called the dealer and asked them to check with the mechanic who did the oil change to see if he may have forgotten to change the oil as I had other work done as well. The mechanic distinctly remembered changing the oil and filter, so I asked them to check their bulk tank. They sent me a photo of a sample from the bulk tank and it is golden. The dealer offered to change the oil again, which I plan to do.

The oil is a 0W-20 which they tell me is a full synthetic from Mobil, although the paperwork shows it as Nissan Genuine Oil (could be both). I did an 5,000 mile UOA on the last change at 50,000 miles, and while about 10% lighter than expected in additives and viscosity, it was still reasonably consistent with API SPs oils and the wear metals were excellent.

I know GDI engines generate some soot, but is it possible for a GDI engine to blacken the oil this much in just 25 miles of highway driving?

View attachment 258976 View attachment 258978
 
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