Excess Oil Consumption in the 3rd Gen Prius?

Any engine MUST consume -some- oil. Some of the oil that is purposely left on the cylinder to lub. the compression rings will probably be burned, and some of the oil lubing the valve stems will be burned. The trick, which as been learned over the years by the manufacturers, is to keep it at the right level. Too little and the compression rings and/or cylinder wear excessively. Too much and the rings get "bound" by carbon deposits, which will lead to more oil consumption.
Typically you will find one litre will be burned between changes. You may not see the level go down, but that is often because fuel will get into the oil. Some of -it- will leak down from the chamber to the oil past the rings.
This will eventually degrade the oil, which is -one- of the many reasons it must be changed at some point.

It seems the GIII engines can be made to burn oil. There is some debate about what causes it. My thoughts go to customers letting the level fall too low, especially when they don't have to change it for 10,000 mi. They may think it doesn't need to be checked anymore because of the long change interval. Anyway, several have posted on this forum that they found "no oil" on the dipstick when they eventually checked it, then blamed the engine for burning it, rather than themselves for not checking it more often and adding when necessary.

 

I disagree. I had oil consumption in the first 10,000 miles and later 70,000-80,000 miles, about 1 qt total, and i check oil every couple of weeks. Never let it low and i ended up topping up several times.

the real answer is low tension rings (for fuel consumption reasons) get plugged up easily. I was able to unstuck mine by engine flush at the last oil change. No consumption 4,000+ miles later.

 

As I posted, "there is some debate".

 

Still think it's the 0W-20 oil weight! It's just too thin, compared to what is being recommended in other parts of the world. CAFE standards are killing the longevity of our cars.

 

There is a high-mileage 0W-20 from Valvoline I've been using which seems to have slowed the consumption a bit, and I've changed the interval to 5k miles to keep whatever additives fresh. Changed the spark plugs at 135k and they seemed fine so I've climbed down quite a bit from my first post here worrying that our 2010 needed a $2000 head gasket job.

 

Good to see you back on another oil consumption thread.

My next change at the end of the March will be Pennzoil Platinum 5W-30. It's base is from natural gas and not crude, and is supposed to help quell oil consumption.

Also will be doing an EPR flush prior with an Extended Life MOA additive to it. Have dropped consumption a fair bit with just the EPR, MOA and Mobil 1. Only have added 15 ounces over the current oil change (7k on this cycle), so much better than the quart every 4500 miles I was on before.

We'll see what this does.

 

I bet everyone on here with a G3 that eats excessive oil complaint is a dealer oil changed car. Vat oil and constant overfill and poor level maintenance will do it.

And orenji's right too for diy'ers the 20 weight is probably too thin especially in a car that routinely see's high speed operation.
If your doing 75-80 miles an hour all the time and thats pretty common you need a very high quality oil in your engine. Its a tiny very hard working motor.

 

Hi Ray....our 2010 is still using oil as well. Next service will be when it warms up a bit - hopefully early April!

I did the following following late last summer :

- Cleaned the EGR pipe ( showed some gunk but it was not plugged ).
- Changed PCV valve ( it looked OK but I did put the new one in ).
- Did the BG EPR flush before the oil change
- Used Mobil 1 5W-30 High Mileage
- A bottle of Techron every now and then.

This seems to have made a very small difference. However, I have not made any precise measurements. Part of the problem is that my daughter drives the car and she drives the engine very hard ( she does NOT drive it conservatively like most of us do ). Hence the engine is working much harder than when I drive it and that certainly shows up with lower MPG and oil usage. However, I drove it on a 4500 mile road trip down to SW Utah late last summer and it did NOT use as much oil as I expected it would. Quite puzzling...Perhaps driving it hard in in 'city' driving affects it much more than 'on the highway'?

When I do the next oil change, I will try :

- Running BG EPR flush again - may run engine longer than last time.
- Use the BG MOA oil additive
- Possibly try this Pennzoil Platinum 5W-30.

I also saw someone was using Liqui-Moly additive...but I cannot locate that post anymore. However, I have used it in my 2004 Mazda MPV with no ill effects...it actually seemed to help it 'run smoother' ( subjective I know ).

Ray, where did you see that Pennzoil Platinum 5W-30 is supposed to help with oil consumption? I had not seen that.

 

Thanks for the update.

The base for the oil is made from natural gas which Pennzoil converts gas to liquid using "proprietary technology" whereas all other oil comes from a crude base. Impurities can result in this base, leading to buildup on pistons, rings, etc. On Pennzoil's website, they say it keeps the pistons 20% cleaner, so a cleaner piston should lead to less blow by, or reduced consumption.

That's the theory I will be testing anyway .

I also saw someone in the Gen2 forums talking about using Pennzoil Pure Platinum with good results in regards to oil consumption. I think it was @69shovlhed or at least he commented in the thread.

Good luck with your plan. I will be at 150 k miles by the weekend and will be changing My oil at the end of March with an EPR flush, 5W-30 Pure Platinum oil and the Extended Life MOA going in.

Hope that helps

 

Yes, that's conventional wisdom, that consumption of less than 1 quart per 6000 or so miles means future trouble due to inadequate upper cylinder lubrication. It looks like the jury is still out, as to whether that rule of thumb has been repealed by modern technology.

 

^ Did you mean this? I think you're saying steady, minor consumption is good?

 

I have been changing my oil every 5,000 miles. I am reaching 23,000 miles now and have not burned a drop. Once I get over 70,000 miles, I am going to use 5w-30. I have changed the weight of oil on all my cars as they age. It just always makes sense. My son's car has over 175,000 and I use a high-mileage oil plus a small amount of motor Honey. No oil burn and no blue smoke. Engine runs smooth. I just go by the basics that overtime, friction creates more space, thus the need for a thicker vicosity. Has always worked for me. 0W seems too light for high mileage motors..............just me.

 

I'm saying that is or was conventional wisdom. In other words, that too low a burn rate in a newish car may cause wear that will cause excessive consumption later (assuming the car isn't junked at low mileage for some other reason). I didn't say I necessarily agreed or disagreed.

Guzzling due to carbon-clogged rings, etc. is a separate problem, although the effect is similar.

 

To add to my post above :

Excess Oil Consumption in the 3rd Gen Prius? | Page 2 | PriusChat

I have been noticing something quite peculiar. When I top off the oil to the top fill marker, it seems to 'burn faster' until it reaches around the midpoint between the two markers...and then seems to slow down substantially. Again, this is subjective as I do need to take better records. However, this has happened three times so far. Really strange...has anyone ever seen anything like this?

 

Interesting observation. I check our 2010 Prius II dipstick every Saturday morning and can say I haven't seen that phenomenon before. Doesn't mean it isn't there though.

Just keep an eye on it and see if it continues.

 

I've noticed the same thing. 2010 Prius 144k. I check my oil once a week sometimes every other week. The lowest it has ever been was halfway mark. I've driven a few hundred miles and oil will not get lower. I'm too afraid to leave it at halfway for too long. I commute 75 miles a day and i'm hard on it.

Also Raytheeagle, I'm curious to try BG EPR fluids. I've been having an eye on the fix you recommend for the EGR ticking. I may try it within the next two weeks. Do I put it in and drive it around since we can't get the prius to stay at idle for too long? 7-8k OCI 0w20 Toyota oil. Used to use Mobil One advanced fuel economy 0w20. I noticed cold starts would sound a lot quieter with Toyota Oil. Tempted to try some German 0w40 oil.

 

I've been using bulk Toyota 0W20 (your "vat" oil I guess), at 6 month intervals, for the last couple of years, and the same stuff but bottled, for the the four years previous, again at 6 month intervals. So far, at 66K kms: no appreciable oil consumption.

 

Very interesting! I was assuming it was 'just me' that was experiencing this but obviously not!

Thanks much for the heads up.


Edit - there is a service procedure that activates a constant idle state. Hmm..I need to dig up where I put that info.

 

Where in the Bay Area are you? If down on the Fremont area, I will be doing an EPR treatment on Saturday. I could show you the ropes if interested.

To answer your question though, there is a mode called "Maintenance Mode" that allows you to run the Prius like a normal car. You put the EPR in prior to the oil change, do the chicken dance for maintenance mode, let it run for 10-12 minutes, then drain it. It comes out jet black!

 

Hi guys...just an update :

I worked on the car a couple weeks ago and did the following :

- Used BG EPR flush again.
- Used BG MOA oil additive
- Used Pennzoil Platinum 5W-30.
- Using Techron fuel additive fairly frequently.

Will post later on to see how it turns out.

BTW - I chickened out on the 'Liqui-Moly' additive...but I am using it in our 2004 Mazda MPV...and it does seem to make a difference. But this is observation is obviously a very subjective one.

Oh and my observation of the oil never reaching lower than the 'halfway' point still holds. Very strange indeed...