Excessive oil consumption

In this context, "coking the rings" means the same as "could be excess carbon build up on the rings". The first primitive step in refining crude oil is to boil off ALL of the lighter hydrocarbons that will boil off. The solids left in the bottom of the "kettle" is coke. That first refining process unit is often called a "Coker Unit".

Someone else said that. My whole point was the weight or viscosity of the oil is immaterial to the "coking" problem. My point was it is the smoke and flash temperature of the motor oil that determines coking, and both of those temperatures are available on MSDS. Select your motor oil accordingly. The lower the "smoke" and "flash" temperatures of the motor oil, the lower the coking temperature. In fact, very thin motor oil like 0W20 cannot be achieved without some percentage of synthetic oil. The problem is that there is not enough synthetic oil to raise the smoke/flash temperatures enough to prevent coking.

There is no guarantee that "full synthetic" or even "100% synthetic" will solve this coking problem. It is safe to assume that the engines have been tested with oils meeting 0W20 viscosity specification, and in most cases, those oils have not resulted in a severe coking problem or Toyota would be specific in their motor oil requirements. If the coking problem still persists after
a "full synthetic" or "100% synthetic" motor oil is being used, then it's an operational problem, or it's a design problem not easily fixed.

In those cases where oil burning has already begun, the coke or carbon will have to be cleaned out of the rings and grooves to fix the problem; simply changing to "full synthetic" or "100% synthetic" motor oil after-the-fact is unlikely to have any effect. Unless, as @empty_lord suggests, ATF or some other detergent product is added with the motor oil, and you drive it like you stole it for a while.

Edit: Above recommendation to select your motor oil by flash temperature or volatility is probably good advice in theory, but I'm finding that next to impossible in practice. I have found that motor oil MSDS are NOT readily available on the internet (Mobil1 is the exception). If you do find an MSDS, the data of interest is often obscured or not available; i.e. Flash temperature >= 201* F. For comparison, Mobil1 0W20 Flash Temp = 428* F.

 

Yep. I mentioned that in one of my long winded posts. I do not blame you for not reading them. LOL.

 

I always thought (maybe incorrectly) that there were two potential different problems. (1) Cooking the oil with high heat that turns the oil itself into a hard solid deposit and/or (2) excess carbon from the burning of the fuel in the combustion chamber that causes carbon deposits (has nothing to do with the oil). I thought coking was from 1 and carbon deposits from 2. Anyway, it may not matter.

By the way, when my truck suddenly started using oil I was using Mobile 1 full synthetic and I was a big fan from reputation of the brand.

 

You’re speaking in past tense about liking Mobil 1, are you not anymore because of this? I’m in the same boat as you, so I was focused on Mobil 1 being the possible culprit for awhile, but the thousands of other guys running it on this forum don’t seem to have a problem. But, Mobile 1 is the only common denominator I’ve seen with respect to missing oil, coincidence?

 

Mobil seems fine, I’ve ran mobil 1 extended in my corolla since it was new, 850k later and it’s still running fine and not burning (it does leak a bit though)

 

Yes, I used to use only Mobile 1 full synthetic but I had a feeling it was the problem (or part of the problem) and others on the internet have said the same for other cars that are having this problem. I think Mobile 1 has also changed, and not for the better, over the years. So I went looking for other options. Pennzoil Ultra Premium is what I am now using (buy at Walmart in 5 quart for around $20 or so) because it claims to clean pistons more than other brands, and that is exactly what I want to do. It is too soon to tell for sure, but I think it is helping the situation. I burned a lot less oil the last two oil intervals. I am going to put some engine cleaning additives in the oil and the gas and probably run a few tanks of premium Chevron or Shell fuel with their cleaning additives through it as well. Part of my problem may be that I drive short trips (10 miles each way to work) and thus maybe that is causing the problem. I think if I went on a long road trip (80 mph for 10 hours or so) that may help heat up the piston and clean everything off. The way I look at it, I think this may be a problem that comes and goes, just like my "warped" front rotor that sometimes feels warped and often later does not feel warped (for weeks or more). It comes and goes because I believe it is sporadic brake pad build up on the rotor (not warped) and sporadic carbon or coked oil on the pistons from time to time. It may also make sense to run engine cleaner through the engine on a regular basis. I know some motorcycle guys do that to prevent carbon buildup on the piston (Sea Foam or Marvel Mystery Oil Cleaner). I am confident that it will all be fine in the long run.

By the way, just because there are guys not having this problem does not mean the problem does not exist. It is a problem for some (maybe the luck of the draw if you have it) and a known problem of Toyota and other brands. I read the same thing about the warped rotor problem (guys saying their rotors are fine). I am not a nit picking kind of guy so there has to be a real problem or I will not create or say there is one. I also 100% believe the original poster and I bet his truck really is using that amount of oil. It is not a fluke.

 

Interesting you also drive short distances, as do I. Less than you actually. I try to get on the highway once a week, but sometimes it’s two weeks before I can. I’ve done BG engine treatment, and I think it helped. Look into the EPR, MOA and 44k, it’s typically sold at high end dealerships like Ferrari.

 

Thanks for the tip. When I was growing up in the 60's and 70's, cars had carbs, ran rich, had poor quality control (tolerances) and thus used oil, etc. and we used to get on the highway to blow the carbon and oil build up out of the engine (combustion chamber) when the cars started to run poorly. In some ways, things have not changed as far as short trips causing some of these build up problems IMO.

 

Edit: JohnLakeman's post below answers the specifics on the oil pressure light. Thankfully, Toyota put a useful gauge in these trucks!

I feel the need to point out a couple things about the oil pressure lights. I haven't confirmed this yet (maybe someone with a 3rd gen service manual will kindly do this for us!), but in my Subaru's case (2016 WRX STI) the oil pressure light would only come on at 2.1 psi. Normal operating pressure was 20psi at idle with a 5w40 in that car! 2.1 is nuts!

Since Toyota and Subaru actually do quite a bit of parts sharing, and the Japanese are notoriously stingy with giving vehicle owners any information on how their vehicle is performing, my guess is the oil pressure light in this truck would be more aptly named an "engine replacement light" as is the case in the Subaru!

If the oil pressure light comes on it's too late! Grab that dipstick more often, ladies and gents!

Last thing I want to say is the only way to know for sure what brand/viscosity (other than what's in the owner's manual) of oil is best for your truck and your use case is through oil analysis. Dyson Analysis is widely regarded as the most thorough service, and best bang for your buck. I've used his services with great success in the past.

 

What brand oil are you using?

 

Apparently, Tundra does not share it's oil pressure sending unit or lubrication specs with any Subarus. These are extremely generous minimums, especially with 0W20 oil:

 

This is great info. Thank you!

 

Maybe they didnt use 0-20?

 

I had a 2014 Subaru Forester with the 2.5i, my oil light came on when the oil level was 1 quart low. It used 0w20 and burned 1 to 3 quarts every 7500 miles which was the oil change interval. They had many complaints about oil consumption and remedied it by changing the interval to 5000 miles. Subaru consideres 1 quart every 1000 miles okay. Personally I believe it has to do with 0w20. Did previous Tundras with the same 5.7 use 5w30?

 

I used to use Mobile 1 full synthetic but lately I have been using Pennzoil Ultra Platinum full synthetic. For the most part, it is not the brand of oil that is the problem.

 

There are tons of people using 0-20 with oil consumption problems in lots of brands of cars, including Honda, Toyota, etc. I have read lots of complaints on the internet. I think the 0-20 has something to do with it too. I thought oil consumption was something that was solved 40 years ago, like spark plugs, radiator hoses, belts, water pumps, and other parts needing frequent changes. I went many decades with cars that did not use a drop of oil until I started driving cars that use 0-20. It's back to the future.

 

Yeah, I'm contemplating using 5w30 instead of 0w20 after my previous experience with it. Any idea what the 5.7 called for originally? Has it always been 0w20?

 

No idea. I looked at the owner's manual for my 2016 Tundra and it is adamant about only using 0-20. Owners manuals used to give a range of different oil weights that were acceptable, but no more. When I had cars that used 5-30 they did not use a drop, even at 100,000 miles.

 

I just went to the Toyota website and pulled the owner's manual for a 2007 Tundra and the 5.7 then was allowed to use 0-20 and 5-20. The smaller V8 used 5-30. The million mile Tundra was the smaller V8 if I remember correctly.

 

I was just reading this thread https://www.tundras.com/threads/motor-seems-louder.5664/ where it was said that the 5.7 originally used 5w30 and only switch for better fuel economy. I tend to believe this since even my Subaru that called for 0w20 said you could use 5w30 if no 0w20 was available and to switch it out next oil change. The only benefits on paper for 0w20 are in extreme artic temperatures. I just bought the truck a couple months ago and won't be doing my oil change til the spring but think I'll go with 5w30 just to avoid the same thing I dealt with last time an engine called for 0w20. Heres the quote from that thread.

 

What year did the 5.7 come out? I assumed 2007 and that is why I went and looked at that manual.

 

I think that quote is incorrect as far as US motors. From what I have read, the 5.7 came out in 2007 and I pulled the manual on the Toyota website and it used 0-20 and 5-20 oil--not 5-30. The smaller V8 did use 5-30. Maybe the poster assumed that because the smaller V8 used 5-30 the 5.7 did too.

 

Yeah your right as far as US manuals. Apparently other countries manuals would also have 5w30 in them, was just readig this thread here https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5150821/1. I have heard in the past the same with other engines that are used world wide have different specs here simply to please the EPA and CAFE standards. I may do 5w30 for spring and summer and then switch to 5w20 for the winter. I think I'm done with 0w considering every new engine that has consumption issues is always a 0w. In the case of the 5.7 it's documented to have been spec'd for 0w20, 5w20 and 5w30. The reason for saying 0w20 only now is simply an EPA thing since 0w20 is going to give the best mileage, apparently there's even a 0w16 oil out now too, pretty soon they just have use running our engines on Olive oil if it means get .01 better mpg.

 

The next time you think of it, look out your right side mirror before you start your truck and watch the area of your exhaust pipe. Watch for a small cloud of blue oil smoke right when you start the engine.

 

I worry that the non-US engines have different engine specifications (clearances) than US engines that allow them to use 5-30. I do not want to damage anything or shorten the life of the engine, oil pump, etc.

 

The Toyota 5.7 3UR-FE is used world wide in the Landcruiser J200, for kicks if you go on Castrols website you can change your country and select your vehicle, the oil changes by country for the same vehicle. Here you can see in 3UR-FE in the Middle East suggested to use 5w30, 10w30 and even 20w50. Obviously climate has a lot to do with a recommendation of 20w50 but as far as the engine goes it's still a 3UR-FE. It's actually kind of fun to go around the world and see all the different oils recommend for the same engine. Makes you worry much less. https://applications.castrol.com/oi...pe=land-cruiser-200-5-7-v8-urj202-(2010-2012)

 

I use the ATF trick before oil changes on my 4a-ge/gze. I only use ethanol free gas with those cars too to prevent the valves from sticking.

 

Some of the guys I know use 0w-0 on their track cars. But do change their oil more often.

https://www.drivenracingoil.com/xp0-0w-synthetic-racing-oil.html

 

i didnt even know that was a thing..

 

it doesn't leak. It marks its territory. After 850k it has the right.