Update to oil-guzzling Scion xB

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May 7, 2018
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Northern KY
Original thread describing the issue here: https://bobistheoilguy.com/forums/threads/boy-did-i-get-taken.348392/

tl:dr is that my recently acquired Scion xB with the known-problematic 2AZ-FE engine was burning a quart of the recommended 5w-20 oil every 300 miles.

In an attempt to remedy the problem I did the following:

1. Did a multi-day piston soak. I drained the oil and left the plug out and the catch pan in place. I then pulled the plugs and distributed a full bottle of Berryman's B-12 Chemtool fuel system cleaner across all four cylinders. I loosely installed the plugs and let it soak for 24 hours. I then removed the plugs, cranked it over a couple of times and poured in a bottle of the SuperTech engine cleaner (Seafoam knockoff) and used a dowel to tap on the pistons a few times to see if a little vibration would loosen them up. Due to a rain shower this soak lasted 48 hours. I then extracted the last remaining bit of fluid with a syringe, installed new plugs and filled it with a mix of leftover oils of various viscosities.
2. I drove it for about 200 miles with a full bottle of Seafoam in the gas tank.
3. I removed and replaced the old filter, then topped it back up with a full bottle of SuperTech engine cleaner and some straight 30 weight. I drove it 100 miles on this oil/solvent mix, then dumped it and refilled with Valvoline full synthetic high mileage 10w-30. The oil was VERY dark for a 300 mile run.
4. I added two ounces of Yamalube Ring Free+ fuel additive to the gas tank.

So essentially I did four different things: piston soak, solvent in the sump, changed oil viscosity, and used a fuel treatment.

Since doing the treatments I have driven 250 miles, about half of which was 70mph highway driving. I am overjoyed to report that the oil level hasn't changed at all! I am absolutely floored by this result--it is FAR better than I expected. My original best hope was that I might be able to reduce consumption to Toyota's stated repair threshold of 1 quart/1000 miles but (fingers crossed) I think I might have even exceeded that.

I'm a bad scientist because I changed multiple variables at once so I din't know which things made the biggest difference. I do know I'm going to continue using the Ring Free until I use up abut half the bottle. I'm going to use the rest of it in my outboard since that's what Yamaha specs it for and if it's as good as they say it might add some meaningful life to my 50hp two stroke by doing what the name implies and freeing the rings.

I'm so happy to be able to report a good result. Thanks to all here who contributed helpful advice along the way.
 
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My grandmother used to have a Chevy Prizm with the oil burning Toyota 1.8. She never wanted to do anything to remedy the problem other than add oil so that was all we ever did. It started burning pretty noticeably at around 60,000 miles and she ran it that way clear out to 175,000 miles adding oil once or twice a week. She gave it to a relative for free when she quit driving a few years ago. He forgot to check the oil level for awhile and it eventually quit. I sometimes wonder how much longer that car might have gone had she taken some steps to remedy the situation. Sounds like you've got a good handle on yours!
 
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CA
My grandmother used to have a Chevy Prizm with the oil burning Toyota 1.8. She never wanted to do anything to remedy the problem other than add oil so that was all we ever did. It started burning pretty noticeably at around 60,000 miles and she ran it that way clear out to 175,000 miles adding oil once or twice a week. She gave it to a relative for free when she quit driving a few years ago. He forgot to check the oil level for awhile and it eventually quit. I sometimes wonder how much longer that car might have gone had she taken some steps to remedy the situation. Sounds like you've got a good handle on yours!
Just curious how often the oil is changed on a car like that
 

Elkins45

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Northern KY
What's your plan going forward?
Minimum 10 weight synthetic oil with frequent change intervals, continue using the Yamaha Ring Free for a while, monitor the oil level frequently. If it starts using again I’m going to spring for the BG treatment kit that Toyota recommends.
 
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Minimum 10 weight synthetic oil with frequent change intervals, continue using the Yamaha Ring Free for a while, monitor the oil level frequently. If it starts using again I’m going to spring for the BG treatment kit that Toyota recommends.
What is a “10 weight” synthetic oil?
 
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Correct. The recommended oils are 5w-20 or 0w-20 but it has 10w-30 now. I don’t see myself ever using a 0w or 5w oil ever again.
Why is that? The winter rating in your area of Northern Kentucky is going to be largely irrelevant. In your example above you're referring to both a 20 and a 30-grade oil, that's what makes the difference.
 
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Let us know the results after a 1000 miles. Touting success at this point is premature.

The 10W30 is a good Idea (less VM % - which is NOT oil and varnishes rings and things)
Adding a pint of ISO 68 POE Refrigerant compressor lube could help too.

I would not put Seafoam or it's clone anywhere near and engine. It's alcohol and paint thinner.

The B-12 probably did the trick

Good effort!

- Ken
 

Elkins45

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Joined
May 7, 2018
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Why is that? The winter rating in your area of Northern Kentucky is going to be largely irrelevant. In your example above you're referring to both a 20 and a 30-grade oil, that's what makes the difference.
My thinking was I don’t want it to ever behave like a 0 or 5 oil because those would slip past the rings easier.. Are you saying I would do just as well using 5W-30? I tried that and it didn’t seem to make much of a difference, but of course that was before I did the piston soak.
 
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My thinking was I don’t want it to ever behave like a 0 or 5 oil because those would slip past the rings easier.. Are you saying I would do just as well using 5W-30? I tried that and it didn’t seem to make much of a difference, but of course that was before I did the piston soak.
Okay but there is no such thing as a “0 or 5 oil” that’s not how the winter ratings work. The winter rating affects the pumping and crankability at low temperatures. Some 0W-30 oils are quite a bit thicker than some other 5W-30 oils except at temperatures below -35 where the two winter ratings become relevant. IMO it’s kind of unfortunate that the winter ratings use a number because it causes the confusion where people think it’s a “0” or a “5” weight oil and subsequently think it’s “too thin”. As has been already mentioned on here it would be better if a different designation was used such as a letter.
 
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