Excessive oil consumption. Issue resolved by Toyota.

Your Gen2 is the only one with an oil catch that I know of, have you caught anything thus far?

 

I have done the motor flush oil change and some crud came out with the oil and on the filter. I was kind of surprised at that. I have only used Mobil 1.

Next up is the Cataclean. It is on sale at the local auto parts store. I am going to buy 2 of them. You are supposed to put it in with 4 gallons in the gas tank. I will do it with 8 gallons.

These are products designed to do this cleaning. I think that they are safe to use. I'll post again in a few weeks and let you know what happens to the oil loss rate.

 

The Cataclean is in the tank. Now we just have to drive the car.

I should also mention that I cleaned out the EGR system last week. And, a very big thank you to Nutz about bolts for the video on how to do that.

 

I would ask why this problem seems to be only in America? I know of at least two other Prius'es with over 500,000 miles in Europe that don't burn excessive oil. Could there be a batch of bad PCVs or is there a specification difference? Can't all be people neglecting to check there oil levels

 

I have just been told that a lot of the the problem in the states could be down to the fuel quality that varies a lot you even have different mixes at different times of the year. My Canadian friend wishes to remain anonymous before you ask!

 

Personal opinion disclaimer:

Euro spec oils (ACEA) are better equipped to handle long oil change intervals without coking the oil control rings. North American oils (API) don't handle it so well, flashing off, coking the rings and allowing oil blowby to combustion. If Toyota had been able to stick to the 5,000 mile oci spec they introduced Gen 3 to North America with, the reports of oil burning would be isolated and likely down to owner neglect. I'm not saying API oils don't return spectacular UOA's in these engines, they do, showing almost no wear metals. I'm saying low HTHS and high NOACK vs. ACEA's make them more prone to flashing off at the longer change interval.

I'd also guess 999 out of 1,000 PCV valves in these engines are fully functional. I'm not saying they shouldn't be changed according to factory recommendation, just that they are not the reason Gen 2 & 3 Prii burn oil.

If this were the case wouldn't there be many other (or all) gas engines burning large quantities of oil? Don't Europe and Canada have summer-winter blend gas variation similar to the U.S.? Is fuel quality variation really a problem unique to the U.S.? What is the mechanical theory behind fuel quality variation leading to oil burning in Prii?

 

As far as I know there is no recommended change interval. There's a testing procedure in the Repair Manual (basically saying to make sure it's not sticking or clogged), and they say to change it if it fails.

 

Thank you for an informative answer that makes a lot of sense to me. My friends theory was poor fuel quality that left deposits that gummed up the rings, he had experienced similar problems in a conventional engined car in Canada that was traced to fuel quality.

 

Many would be interested in knowing more about this traced theory, if s/he is willing to share such.

 

I shall see him before he goes back this weekend I will ask

 

Not much difference.
I'm going to start using Mobil Full Synthetic and see if that makes a difference; will be a couple of more oil changes before I try that since I need to finish my conventional oil.

 

Every 3k miles I catch about 3-4 ounces; I recycle this little along with other oil when I change the oil.
This is a good link to create your own oil catch can:

I used a mini air filter from Harbor Freight and similar components; will try to post a pic.
The thing with the Prius is that you don't have much space under the hood where to have an oil catch can so you need to get a filter that is very compact.

 

It has been more than 3 weeks since my last post about using Cataclean and Motor Flush. The oil level today is down 1/8" from the full dot. This is a huge improvement. Before the chemical cleanout it would have been down more than a quart. I went from losing a quart and a fraction to just losing a fraction of a quart. I wonder if I should do another Motor Flush with the next oil change. I am not sure where the oil level was after the oil change as I checked it before running the engine, which fills the oil filter and changes the level on the dip stick. It was above the full dot before running the engine.

The Cataclean requires than you drive the car after you put it in the tank. I would suggest lots of freeway driving for the best results.

 

I've also had better results switching over to 5W30 (Valvoline in my case). At 130K, my 2010 prius engine was burning 1 quart every 1500 miles. Now, I have 2000 miles since the 5w30 change and found it about 2/3 qt down, which works out to 3000 miles/qt. I don't notice any difference at all in mileage.
On a related topic, I recently bought a high mileage used pickup for my farm. Because I'm so thrilled with Toyota, I bought GM. This truck spent 5 years in oil field service and came to me with 215 k miles on it. The 4.8L V8 runs smooth as silk and burns no oil. And it cost ever so much less than people wanted for used Toyotas. And when I needed some parts for it, I was shocked at how much cheaper they are as well.

 

Appropriate name.

 

Here are the pics:

 

Did you use Valvoline 5W30 synthetic or dino oil?

 

It's been a few months since you tried the Cataclean and the Motor Flush. How are things going with your Prius?

 

It is looking good. It has been about 3000 miles since the clean out and the oil level this morning was almost a 1/4 inch below full. I haven't topped it up since the last oil change and clean out. I would have put in a couple of quarts to replace what was lost before I cleaned it out.

 

Thanks for the update! Keep us posted, if you will.