126k mile gen II consuming oil

I think its early for your car to have oil shortage problems, but its not unheard of though.

Replacing the spark plugs, has got nothing to do with oil shortage or consumption issues.

The spark plugs, would only give you an idea of what the state of the internal combustion chamber of your car is, and sometimes, tells you, from inspecting the plugs, if they need to be replaced, or if there are issues with the top cylinder (overheating problems).

Its too early for you to tamper with the head gasket for now, since there isn't any signs of engine oil contaminated with coolants.

I heard some folks over here, use seafoam, or something like that.

If that doesn't solve the problem, you might ha e to prepare tearing the engine apart to replace the piston oil rings, or get a used low mileage engine, which you might not know the history, or trade in the car, and get another one of your choice.

If you aren't comfortable with embarkiyon an engine overhaul, it would be cool, you let a mechanic you trust, do the job.


Dxta

 

I am wondering why you seem to think it is prohibited / not allowed to check the engine oil level, in between oil changes. If no oil is showing up on the dipstick, it is at least 2 quarts low and you are causing damage to the engine by allowing it to run it that way.

May I suggest step 0:

0. Check the engine oil level at least once per month and add sufficient oil to keep the dipstick level at the top mark.

Then you can defer #3 on your list.

 

If you've never replaced your PCV valve, you might want to. A plugged valve makes oil look for other escape routes.

 

Its a symptom of lack of maintenance.

Don't bother replacing anything. You have turned it into a little oil eating monster due to lack of maintenance and most likely damaged the engine. If you have ever run it so low on oil it turned on a dash light its pretty much done. The light means the oil pump is sucking air not oil. The oil ring on the pistons are damaged from lack of lubrication.

As a car gets older it needs more care and inspection not less. My car is one year older and same miles and uses no oil whatsoever.
That because I check it every Saturday without fail and even if its a tiny bit low on oil I add oil till it gets to the full line. Its a tiny engine with only 3.5 quarts. if your down 2 quarts that 65% + of the oil missing. You don't think that's not going to damage the engine?

And if your losing engine coolant its most likely because the engine water pump is leaking at the weep hole. G2's do not use a drop of coolant. if its low its leaking. Or in your case if the engine overheated from lack of oil and the head gasket is blown.

 

Definitely, adding oil, is just not treating the real cause of the shortages.

Have you checked the valves cover gasket for leaks? Sometimes they get to crack from old age. The crankshaft pulley seas and the big seal in between the engine and trans axle, are known to cause such leaks also.

 

If you don't see any oil leaks pass the valve cover gasket, and the crankshaft seals, it appears you have worn out piston oil rings already. There's nothing that can be done in the interim to stop the oil shortages. You either have the engine rebuilt, or get a used low mileage one.

 

Fair enough.

Your dealer is a rarity concerning the oil level concern. But there's another issue with the dealer oil change and thats throwing them the keys and say change the oil. They will use vat Dyno oil which is a very low grade oil comparatively to say synthetic oil in quart bottles.
Thats not helping an oil loss issue either. It tends to leave quite a bit of hydro carbons which is just gunk which doesn't help oil circulation.. You may have a very clogged pcv valve and throttle body.

Take the air cleaner box off some 10MM bolts one underneath thats a throat clamp and 2 bolts to the valve cover and open the butterfly to the throttle body and with a flashlight see how funky it is down there.

Move up to 10-30 oil. Go to Walmart and buy a 5 quart jug oi Mobil 1 10-30 for $24.95. Run that for a while.

 

Oil consumption is not a rarity, and I wouldn't consider it abnormal. Our Prius is the first car we've had with no apparent consumption, so far (knock on wood). I'm changing oil on a couple of Honda's too, and both of them have a bit of a "drinking habit". You just top it up and keep going. And maybe go to a heavier grade. As a last resort, go to "high mileage" oil, but resign yourself to sticking with it once you start.

 

Asked and answered.

FWIW however, the people who built the car do not consider 1-2q of oil during the normal OCI to be problematic, but of course their definition of "abnormal oil use" is based on when THEY have to do something to fix the problem.

If you look in the owner's manual.....a few pages after the part where it tells you to check the oil level every month or 1,000 miles and add oil if necessary......you will find what the mother ship considers to be "abnormal oil use."
IIRC....it's something like 1 quart every 600 miles......which is about the rate of oil consumption required for mosquito control.

All kids smoke and drink a little bit (or a LOT!) when they enter those troubled years after their 10th birthday and all cars do likewise........and yes........it depends on how well they were taken care of during those formative years!

Going forward:
1. There are no retroactive oil changes.
You can't try to make up for neglect by getting your car presents in the Marvel Mystery Oil section of your local parts house.

2. You need precise measurements for your burn rate and more importantly, the rate of change. If you keep your oil volume topped off, you are very likely to log another 100,000 miles in your car at its present wear state.

3. If it runs good......it IS good.....or.......how is your fuel efficiency?
If you're still knocking down most of 50MPG, then your car is running well.
Go back to #2 and reassess.

4. Consider clubbing down to a 5K OCI.
Note(!!!!) this means oil CHANGE interval......NOT oil check interval.

5. As a last resort, you may consider clubbing up to a 5w30....along with the 5K OCI.....but I personally would not do this unless my burn rate was more like 1-2q every 3,000 miles......



Good Luck!

 

Just to be clear, it's not exactly a specific oil light but more of a general purpose "idiot light" to show that something is wrong in the vicinity of the engine. When it comes on then I think that some more specific information (like low oil) gets displayed on the multifunction display. Also as the oil gets low it often happens that the warning just flickers on for a second or so when you are braking hard or cornering, so people sometimes don't notice it.

Well if the cause is engine wear, then adding oil is doing more than just treat the symptom, it's definitely also managing the cause.

The Prius has a pretty small sump with only a little over 3.5L capacity. So once you get down by about 2L, even if it is still pumping (and not sucking air) then you still might get compromised lubrication simply due fact that the remaining oil is getting worked so hard. The less oil in the system then the less time it sits in the sump before getting pumped back through the engine and hammered again. Also any contaminates like fuel dilution are going to reach much higher concentrations. By the time you are even close to getting a pressure warning then you're likely to be running on about 1.5L of degraded and very much over worked oil. Things can go from bad to worse really quickly at that point.

Most of these engines seem to develop at least mild oil consumption around the 100k mile mark (or sooner), and keeping the oil topped off is the most cost effective thing you can do to keep it manageable.

 

Yes Uart I always forget the fuel dilution. This car has very high fuel dilution. The oil stinks of fuel always has. So thats another oil issue. Much more stinkier on the dip stick than my gas guzzling beasts.

My car started to eat a tiny bit of oil at the 100K mark as you say which was disturbing because of my high maintenance level and how much I pay attention to the dipstick. By mistake I found out that if I over fill the oil just a tiny bit it uses no oil whatsoever. Hasn't eaten any oil in the last 10,000 miles keeping it about an 1/8 inch over the full mark. I use 10-30 Redline which after it warms up is a 10-40 weight. I'm taking a slight hit in mpg's but don't mind if the motor likes it and it seems too.

But your post was right on.

 

My 2006 Prius has had a mysterious oil burning issue forever. Burns oil but does not leak on the ground, on the engine or anywhere else. just gone. They said change the engine or check & fill the oil more often. HMMMM, So now I carry oil with me and try to remember to add a quart every week or so. It is a hassle but much easier- cheaper fix than a new engine. Costco carries a case of oil quite reasonably.

 

how many miles per quart?