Oil sludge 7K after the last oil change

I checked the oil dipsticks of my 2016 4Runner and 2017 Tacoma 7k miles after the last oil change at the local dealership recently. Both were around 7k after the service and around 4-6 month after. I was surprised to see black dirty stuff on the dipstick. I'm concerned about the oil they used and if 10k interval is really sufficient to keep the engine clean although I've seem may discussions that the majority trust Toyota engineer's recommendation. I heard dealer has both full synthetic and synthetic blend and wonder if both of them have the same oil life. Anyway, I started changing oil myself with Mobil 1 full synthetic oil and will check it frequently, probably will go with 5-7 k OCI. What's you opinion and preference? Anyone had similar issues?

 

That's really my concern about going so long. I may end up changing mine early.

 

Seems pretty extreme. Are you positive they did actually change the oil? Mine has been in there about 5K and looks like brand new.

 

Generally fully synthetic will last longer than a blend. Is this sludge from when Toyota did the oil change? or from when you last did yours? If so would be interested in what oil you used for the change or if it was the dealer is this the blend or the synthetic when you saw this?

 

Yuck. I've changed mine twice so far at 10K mile intervals and it looked fine.

If you still have some of that oil, I'd send a sample to Blackstone Labs for analysis. It would be interesting to see what they find.

 

+1 send a sample to blackstone labs. I haven't seen that type of crud before.

Do you do a lot of short trips under a mile?

 

The Tacoma was serviced last Dec. under the free ToyotaCare at 20 k. 4Runner was service at the same dealership at 35k and I paid they for the service. It's the largest dealer in this area and i think they should have changed oil. I did find the oil filter caps were very tight and I broke one then replaced it with a metal cap from Toyota. Here's the picture of reverse side

 

Have an oil analysis done from Blackstone Laboratories.

 

The color of the oil is not a definitive indicator of its performance. If you're concerned, drain the oil and send a sample off to Blackstone for analysis.

 

Some local trips but not that short trip often.

 

You found this stuff on both your Taco and 4R?

I'd be shocked that *any* oil would cause this in just 7k.

 

Yes, both. I'm disappointed too. Have reach out to the dealership but haven't got their response yet.

 

My guess is they never changed your filter. Dealerships are dangerous places.

 

They can be, definitely. It’s worth it to DIY, especially when there are resources like TW and YouTube, there’s almost no excuse. Dealership techs wear Toyota shirts, but aren’t The Toyota most people are thinking of.

 

I don't know what the black spots are but the oil looks fine. Like others have said send it out for testing.

 

Making me scard to even drive past my dealer .

 

To be honest, your dipstick makes me wonder if they even changed your oil. They could have just pulled the dipstick and thought it looked fine and not even bother to drain and refill.

 

It’s most likely from condensation in the engine get an oil catch can and be done with it.

 

Took over oil changes on our 2014 4Runner and canister was full of sludge. Not sure what the dealer was doing on the free maintenance but they were definitely gouging up the rims with the rotations. 2018 4Runner will be self maintained. 2017 Tacoma has been from new.

That oil looks too gritty. Almost like our last diesel.