Engine Oil Burning?

Howdy Jason.

Your situation is pretty much mine, too. Looking forward to what folks have to say.

Not doing any maintenance until it warms up.

 

Wth, LoL (well, that's fun) there are a bunch of great posts on the subject here.

What yr is your car? Mine is a 2010. Which if I had checked here b4 buying, I might have chosen differently.

Really good folks and information, here.

 

The 2010 has had some, amazingly enough, oil burning and head gasket issues.

Yep, I was happy too after buying. Snork.

But there are steps to remedy. I'm just not diving in till spring.

 

My sisters 2010 had a bad oil drinking problem, and at around 175k or 185k the headgasket started leaking. We replaced the engine this summer. It has over 220k now. Original everything else that I know.

 

Besides the gas engine they are rock soild, amazing cars

 

Have you had it since new?
What kind of driving do you do mostly? Sedate around town? Hard stop-and-go? Sustained high-speed freeway? Lots of hill climbs?
How frequently have you changed the oil and filter?
Throughout it's life has it ever been run low on oil?
Cleaned the Exhaust Gas Recirculation circuit, the whole thing?
Cleaned the intake manifold?
Cleaned the MAP and MAF sensors?
Look into Oil Catch Can?

Our 2010 is at 73K kms (a youngster), we drive secondary highways and streets, stick to speed limits, and the oil and filter are changed every 6 months regardless of low kms (4~5K), with Toyota 0W20 and the Toyota filter. No discernable oil loss so far, knock-on-wood.

I don't mean to crow; I'm actually a bit puzzled: all our previous Honda consumed a modest-to-moderate amount of oil between oil changes. Not a lot, at most a quart top up requirement required somewhere along the way to the next oil change.

 

We have a 2010 Prius II with 171 k miles and going strong .

At around the 120 k miles mark, I noticed some oil consumption at the quart every 4500 miles rate.

I’ve been able to work it down to 20 ounces between 10 k mile oil changes.

Main factors:

• Check oil on dip stick every Saturday after sitting overnight
• drive 0-5 mph above posted freeway speed limits
• Went up to 5w-30 full synthetic oil
• Buy top tier gas
• Perform engine flush with BG Products EPR before oil change
• Add BG Products Extended Life MOA with new oil

Oil consumption can be managed .

 

There are many threads around here where us poor 2010 owners lament....and try to fix....our oil consumption issues. Ours started consuming around 90K or so.

Unfortunately, it is almost always the 2010s that have the issue. There are many, many theories as to why...just search around on here . I don't think there has been any consensus whatsoever as to what is causing it but the main contender seems to be a '2010 piston ring conspiracy theory'.

It is annoying but has been manageable so far.

 

So based on your answers to @Mendel Leisk ’s questions, how low was the level on the oil dipstick at 148 k miles?

While what Mendel is recommending is not in the owners manual, we here in Prius Chat have found these problem areas and try to advocate addressing them to avoid future problems.

BG Products EPR is an engine flush that cleanses the oil side of the engine prior to dumping the old oil out. I have noticed a difference in what the old oil looks like coming out (jet black) versus not doing the EPR flush. We do meet ups out here in the Bay Area and several members have done oil changes when I have at the same OCI. Since the miles and terrain are relatively the same, I can compare side by side relatively easy .

I have had the same route to work for 4 years and 90 k miles now, and the oil burn started a couple of years back while performing my 38 mile one way commute.

When I found our oil consumption I could still see oil on the dipstick and would add as it got a bit lower on the stick. Since I had a quart jug, I knew the consumption rate without the level disappearing below the low level mark or a dash light quickly flashing telling me about the problem.

The MOA is a product that extends the basicity of the oil. As the oil ages, gas creeps in and contaminates it, causing the oil to now become more acidic (or lower the pH) which will then attack components .

I notice that the consumption in our Prius only really starts to uptick toward the end of oil change interval, say starting around the 7500- 8k miles since the last oil change. This is with the MOA in the system.

Where are you located? Are you the DIY type?

Hope that helps.

 

The Exhaust Gas Recirculation circuit works basically per it's name, taking exhaust gas, running it through a small radiator to cool (somewhat), then through a computer controlled valve, a pipe, into the intake mainifold, finally through small diameter channels at each intake port.

All along this route carbon gradually builds up, as the car accumulates miles. I'm not sure of the net affects of this clogging, but I believe the EGR cools the engine, by design, and the more clogged it becomes, the more it departs from design, getting hotter.

There's at least two sources of intake manifold manifold fouling:

1. the aforementioned EGR gasses enter through a port, run down a gallery, and then into 4 small diameter channels to the intake ports. They clog with carbon.

2. The Positive Crankcase Ventilation circuit, crankcase gasses enter through a port, below and a bit upstream from the throttle body. It tends to condense water/oil/gasoline where it enters, which accumulates under the throttle body, fouls the Manifold Absolute Pressure sensor is in the vicinity. I would think there's also a fair amount of the moisture that stays air-borne, flows up through the intake manifold, back into the combustion chambers.

3. Besides the above, it appears the Atkinson cycle engine causes a small amount of oil to spit back out of the the intake ports. I'm not really understanding this, but that's what I saw, revisiting the intake manifold maybe a month after cleaning and Oil Catch Can install.

There's a specific cleaner, described as "MAF Sensor Cleaner" (Mass Air Flow). I believe it is safe also for the MAP sensor, and have used it for both. The MAF sensor is bolt-on, on the side of the air filter housing, and when I cleaned ours, it looked pretty much pristine. My main concern was actually the MAP sensor (in intake manifold, just below throttle body). When I cleaned the intake manifold, the MAP sensor was basically swimming, in whatever the PCV was dumping in.

The OCC is installed along the line between Positive Crankcase Ventilation valve and intake manifold. It's function is to allow the gasses to flow through, but condense airborne "stuff", whatever it might be. It needs to be periodically emptied, and extra maintenance item. Also, the engine bay is pretty packed, figuring out a practical spot to install it takes some thought; there's several options.

References:

For cleaning the EGR and intake manifold, you can't go wrong watching @NutzAboutBolts videos, pinned at top of maintenance forum. Also, specifically for cleaning the EGR cooler, I'd recommend repeated soaks in strong/hot Oxi-Clean solution. 5~6 hour long soak got mine back to brand-new clean throughout.

There's a CRC MAF sensor cleaner video on youtube, it's pretty straightforward.

For OCC discussion see @danlatu 's thread:

Oil Catch Can, Eliminate that knock! | PriusChat

 

Since the light on the dash alerted you to the low oil scenario, you’ll now have a Prius with a drinking problem .

You now need to monitor frequently to avoid the situation getting worse.

With regards to part numbers, EPR is part number 109. You put the 12 ounce can in prior to the oil change and run the Prius in “maintenance mode”. Run for 10 minutes, then drain it out .

Every oil change I have done with EPR has come out jet black and much darker than comparable oil from just draining . It has to get this from somewhere.

As for adding extended Life MOA, this is done with the new oil. I add ~1 quart then add the MOA then finish the oil addition. While these do add to the cost, this is still cheaper than a dealer oil change .

Hope that helps.