Prius burns oil, how to prevent from happening?

[TheKracken]

Howdy everyone, so I have owned a gen 2 prius (09) with 240+k miles that burned about a quart every 1k, and I will be
buying a newer gen3 prius (2011, 84k miles) and I want to know how to prevent the oil burning from starting? It is a pretty common issue on these vehicles and tends to just get progressively.

Would it be worth buying more expensive oil than just the M1 AFE 0w20? Such as Pennzoil Ultra or amsoil (in 0w20 for both) would this help keep things from happening longer maybe?

Also interested in trying out Ravenol 0w16 super fuel economy (11$ a quart!) since I finally have a vehicle spec'ed for 0w20 from the beginning.

 

[oil_film_movies]

The Ravenol 0w16 with its HTHS=2.4 will work OK in a Prius, and indeed I think (correct me if I'm wronng) Priuses in Japan use 0w16 all the time. Just not in the U.S. yet. Ravenol is a bit expensive. You should gain about 1 MPG or so compared to a 0w20.

If it was me, I'd use Mobil1 Extended Performance 0w20 and change once a year or 15k miles, whichever occurs first.
Toyota engines have been known to gum up their oil control rings and/or get ring sticking from deposits. The Extended Performance flavor of Mobil1 should do the best one can do to get rid of the muck that can collect on the rings. Walmart or amazon has that kind of M1 for cheap too.

Also, at oil change time, put an Engine Flush (walmart, autozone) in the sump for about 2 or 3 miles of driving before changing the oil right then.

Also, put on a good oil filter, like a Fram Ultra, or if not available for that engine, use a Fram ToughGaurd or Wix or M1 oil filter as a second choice.

 

[JMJNet]

There are a toyota engine 2.4L between 2006-2008 (may be more) that have the issues.
They actually issue a limited service warranty works on them.

I am not sure if the particular Prius you have uses this engine as the base.
If so, that may explain the issue.

In my experience helping my friend with a Rav4 burning oil.
I put the expensive synthetic oil and it was still burning like crazy, no matter what I did.
In her case, she got the stealership to fix them with the LSC warranty/recall.
So far so good.

Moral of the story, there is no prevention you can do if internal parts are defective from the factory.
You either fix it or keep using it till it fails just by adding oil.

 

[mightymousetech]

Change the oil more often.

 

[javacontour]

 

[barkingspider]

Do a piston soak and replace the pvc valve if applicable. Then change the oil every 5k miles w Clearance oil.

 

[Olas]

Once you have found out wether the oil burned is going past the rings or the stem seals you can repair the faulty part and the leak will stop.

 

[Kuato]

I know it's sacrilege, but how about using a 5w20, or even a 5w30? That may slow your consumption.

 

[zaffo757]

Changing the oil weight will probably not address the issue as far as the problem developing in the first place. Toyota has failed at a simple engineering task with the rings or the valve seals. All you can do is address the symptom by going to a heavier oil and paying the price in terms of efficiency, which should not be a big deal.

It is funny that we are having the same issues with a modern high tech engine that we had with a 60s small block v-8 - switch to straight 30 or 40 weight to combat wear induced oil consumption.


Originally Posted By: Olas
Once you have found out wether the oil burned is going past the rings or the stem seals you can repair
the faulty part and the leak will stop.

 

[zaffo757]

Never ride in a helicopter that isn't leaking oil. Helicopters that are not leaking oil are out of oil.

Originally Posted By: javacontour

 

[Hootbro]

Prius burning oil. Has to be some irony in that.

 

[bubbatime]

You are running synthetic 0W20? This one is easy. Try a run a Castrol conventional 5W20 or 5W30. Why Castrol? For some reason, I have seen that oil burn much less than many other oil brands.

 

[Oro_O]

Originally Posted By: TheKracken
...I want to know how to prevent the oil burning from starting? It is a pretty common issue on these vehicles and tends to just get progressively.

Would it be worth buying more expensive oil than just the M1 AFE 0w20? ....


I have a different Japanese vehicle with serious oil burn from poor ring drain design. I don't know if that is the exact underlying issue with your Prius, though I know some earlier Toyotas do have this exact issue. The way to keep it from happening is to use a high HTHS oil, not a low one like a 0w16. It's not the price of the oil that matters, but the strength. In Seattle, I use a 10w30 Mobil 1 (very climate approprite) to reduce oil consumption once I cleaned the rings. Preventing the deposits in the first place is vastly easier than trying tricks to clean them. It may cost a small amount of MPG, as their is just no free lunch here.

 

[oil_film_movies]

Originally Posted By: Or
I have a different Japanese vehicle with serious oil burn from poor ring drain design. I don't know if that is the exact underlying issue with your Prius, though I know some earlier Toyotas do have this exact issue. The way to keep it from happening is to use a high HTHS oil, not a low one like a 0w16. It's not the price of the oil that matters, but the strength. In Seattle, I use a 10w30 Mobil 1 (very climate approprite) to reduce oil consumption once I cleaned the rings. Preventing the deposits in the first place is vastly easier than trying tricks to clean them. It may cost a small amount of MPG, as their is just no free lunch here.

No. Not a high HTHS oil. The problem is oil flow in the ring area. Every engineering study I've seen has said thick oil moves more slowly through the oil drainback holes near the rings. Its also intuitively easy to understand. Normal Toyota-recommended 0w16 or 0w20 will have a greater mass flow rate through the ring area, and the synthetic basestocks will keep oxidation to an absolute minimum.

Since their could be differences amongst different 0w20 oils out there, at least choose one you know passes the extra WPD tests in dexos1 for cleaner pistons. Using a long-drain oil such as Mobil1 Extended Performance means you have one thats made to be more stable over whatever oil change interval you choose.

 

[Greg L]

I have the same issue with my 2007 Prius. Have to top off with at least 1/2 quart every week.

The only brand that seemed to slow it down was the Mobil 1 Extended as mentioned above.

Once the valve guides wear down on these engines, you are stuck....unless you want a major repair.


The only odd thing that used to happen with the frequency of oil top-offs was when I used a generic oil (Essential Everyday brand in 5w30) and blended it in. This slowed down consumption quite a bit...until my local store closed & no longer carried it.

GL

 

[philipp10]

Quart every 1000 miles? Big deal, buy a case and don't worry about it.

 

[nthach]

Oil burning is a common malady amongst Toyota I4s - the 1ZZ-FE used in the 1998-2002 Corollas had a problem with the rings coking up, which clogs up the oil return holes in the pistons. The Camry/Scion tC was affected in some model years, Toyota issued new pistons - and the 3rd gen Prius has a TSB out for oil consumption. Luscious Garage in SF has been seeing Prii in taxi/Uber duty using a quart of oil a day. My suspicions is besides the fact that Toyotas are just hard on their oil, hybrids don't load down the engine during deceleration. I doubt a Prius or the Camry/Highlander/RAV4/Lexus hybrids do drive their engines to redline or let them spin without fuel during coast.

I have my parent's hand-me-down 2nd gen and it recently started to use oil, about 1qt between OCIs. The car saw mostly PP and M1, with the occasional fill of PYB or Valvoline SynPower, I dumped the OEM fill at 1000 miles and used QSGB until 5K. I recently ran Liqui Moly's engine flush at the last OCI and used Castrol Edge HM and it helped somewhat. I did run MMO for the last 500 miles before this OCI with M1HM 5-30. We'll see what happens, being that M1HM is close to a Euro oil on paper. I've been toying with the idea of an engine rebuild - new rings, new valve stem seals, cleaned pistons, new timing chain. But if the oil use is low, I'll be happy.

 

[Oro_O]

Originally Posted By: oil_film_movies

No. Not a high HTHS oil.


Yes, really.

The issue is to keep the oil from breaking down. At operating temperature, the oils are going to flow adequately. the problem arises from break-down. The national technical manager from Acura went through this with me, and the users who've followed his advice have seen the issue abate. BUT - I don't know what causes the Prius issue, but if it's the drain-back problem because of inadequate holes in the piston walls and rings, thinner or "weaker" low HTHS oil is not the answer (as real-world experience shows).

 

[Greg L]

^ +1

 

[TheKracken]

Thank you everyone for the replies. I just bought the car today and I do not believe it is burning oil yet...but it is a VERy common issue and the general consensus is that it is from the oil rings.

I would rather not run anything heavier than a 0w20 at this mileage. When I get to 150+k I might consider going up a grade and then again over 240k (I started running rotella t6 in the last prius at 240k.,...crashed 300 miles late so no idea if it helped).

I will take a look at M1 EP oil and see if I like it. I am a pennzoil fan and amsoil fan personally but I wanted more info in regards to oil burning and which oil is best. I have 2 cases of M1 AFE 0w20 that I might use, but I was planning to just use that in my sienna. We will see I guess! Any more input would be much appreciated!