Oil sludge 7K after the last oil change

I understand your frustration. I am stubborn enough to push the issue with a dealer. I may have called for the service manager or the general manager. The Toyota manual is very clear. 10K OR 12 months.


My Nissan 4.0 states to use 5w-30. At one of the free oil changes the dealership put in 0w-20 synthetic. When I called the SA on it he says that is the weight of synthetic they use. I told them to either put it in writing that 0w-20 is ok for the 4L and they would be responsible for any future engine problems or they could put in the correct weight. They changed the oil and put in 5w-30. I watched to make sure they did.

Even Nissan says to use only oil recommended in the manual.

 

All businesses are in it for the money. Otherwise they wouldn't be in business.
However, it is whether or not they truly care about customer service and doing the right thing ethically that separates the good from the bad.

 

.
...^^^...

 

10 k is fine but that oil looks dirty. I sharpie the filter but normally watch them because the tech is asking so many questions.

 

I think there is something else going on. If they didn't change the oil it would be darker, but not.. "clumpy" There is literally a chunk of something on the edge. I've seen some dirty oil, but nothing like that. I would definitely get it tested. I don't know if its condensation or some other contaminant.

 

The minimum I would do is 6000 miles or 6 months.
There are different grades of synthetic oils, you need to use the high quality grades.
Cheap oil 3-4 months...

Higher grades oil, means better quality of oil, resistance to heat, higher boiling point, ect. the oil will still get dirty just as fast...
The boiling point of cheap oils is around 210-230 for light weight oil, just enough to run the engine.
when the oil over heats you loose oil pressure and start to bake the oil, sludge...
Amsoil boiling point is around 240-250...

So to run 0-20 you need to run the best oil you can find just to do light towing and off roading.
For heavy towing and off roading 30 to 40 wt oil will be needed...

Thicker oil has more cooling and will drop oil temp down around 10-20 degrees each step...

Some dealers just use cheap oil but tell the customers...

 

Yup. I too think it's a symptom of something else.

 

Perhaps the barrel they keep the oil in has this stuff in it.... wonder if it’s metal or...

 

What the hell is an oil catch can? Why do we need it? I'm working on Tacoma #3 right now I'm at 750,000 or more between them never even the slightest hint of engine trouble on any of them. They have all called for 5K oil changes that's when they get them. "Sludge"? Shoot modern oil does not sludge at all of you change it some time before 25K!

 

No all kinds of incorrectness here.

 

The recommendation given to me from a life-long auto technician who has seen it all (including newer cars (with the 7k-10k oil changes) is change the oil every 3k miles if conventional oil and every 5k if synthetic. Use the weight recommended by the manufacturer. Clean oil is cheap insurance and synthetic is worth the money in extra protection. A 10k oil change interval is insane, but not surprisingly comes from the company that wants to sell or lease you a new car every few years. Dirty oil will exacerbate the valve carbon buildup issues in GDI fuel injected engines and since oil pressure is key in the VVT system you want clean oil in your engine. If you're getting the free 10k changes from the dealer, do one yourself every 5k miles in between. A Tacoma is probably the easiest vehicle made on which to change oil so owners should do it themselves and they won't have to worry what is actually coming out of the hose at the oil change place, whether the kid put the correct quantity in and you can use a top quality filter unlike the cheap no-name filter the oil change place will use. You won't have to worry about stacked oil filter gaskets, stripped drain plugs, unchanged filters or incorrect fill quantity.

 

Also a lot of bad information from your guy

 

It's well known that 3K oil changes are now largely a waste of time and money with modern engines.
But hey, do what makes you feel good.
I always follow what the manufacturer recommends. 5K, 7.5K, or 10K. Heck, they're warranting the engine so I don't feel they'd push things to an unsafe time frame.

 

Such as?

 

When the oil is dirty you change it. There is no magic, it's either dirty or clean.
Same with your transmission fluid and coolant. there is no such thing as long term fluids, it's just marketing.

Use will determine when to change the oil. On the race bike we change the oil every 150-200 miles.
We live in the north so 6 months is the max you should run your oil here.

No one giving advice here has rebuilt engines with sludge, I have. When the oil is dirty you need to get it out of the engine.
The boiling point goes down and the oil has reduced lubrication and cooling.

For normal use changing the oil 6 months or 6000 miles is the minimum I would do.

But if the oil is clean it is still clean...

 

smh

 

You think?

I still have no problem going for 10K. I have been taking samples to see how well it's working and to give me a heads up when problems arise. I don't see any issues so far.

 

If the oil is clean I guess it would be ok...
But once it turns brown it's getting contaminated...
Those test aren't at 230 degrees they are at room temp so they are misleading...
Why would you want to run your oil for 10K???

20 weight oil is really only good for 230 degrees after that it will start to break down and loose oil pressure...
You would have to monitor oil temps and oil pressure to really know when it breaks down. (data log)
But why push it??? Just change the oil, it gets recycled any way.. 6000 miles is a lot of driving on a 20 weight oil...