2013 Prius sudden oil consumption, PCV valve ok

Has the egr circuit even been cleaned? Along with the intake manifold?
Cleaning the pipe is only a small portion of it. The EGR Cooler gets clogged,
and the egr valve also. That's why you need to clean the how circuit, at the same time.
And you can clean the intake where the valves and injectors are, when the intake manifold is off.
They will probably be very oily

And possibly a new pcv valve. Cleaning it might help, but since they are only $8-10,
it's worth replacing.
Ring could be a possibility, but it's more likely the valve guide seals.
Oil will build up in the intake manifold. And oil catch can will help control that.

How fast are you driving? 70+ mph and up sucks oil.

 

Our 2010 would consume a quart of oil every 4-5k miles.

More when I upped the speed it would go.

Has the car ever been run low on oil before?

If allowed to, this is the cause usually for the rate of oil consumption your father is experiencing.

Cleaning the egr circuit stem to stern, using oil flush products (like BG Products EPR) and clubbing up (I went with 0w-40 at the end) is what I did. Some those can work.

Good luck and keep us posted.

 

I'd focus on the crankcase pressure. The oil consumption is a symptom of that. So get the pressure down. PCV would be the first place to look. Maybe replace vs. clean. Confirm the full PCV system is clear and working - so the tubing, etc., not just the valve itself.

 

So 13 k miles in less than 3 years.

I'd just monitor the dip stick frequently and add oil as necessary as there appears to be downtime as the miles aren't piling on from his ownership.

Situation can be managed with data.

 

Spring might weaken a bit over time. Wouldn't that improve flow though? Yeah I've hit ours with carb cleaner a couple of times now, basically the two times I had the intake manifold off. I used a little Permatex Thread Lock 243 on the threads. Mainly as a make-do thread sealer. It's cosmetic I think, just to avoid a slight oil bloom around it.

Here's a little Repair Manual info, testing it. Still, if you've shot carb or brake cleaner through it, and it's rattling freely, would think it's good.

 

My 2010 Prius burns a lot of oil. Burning oil cloggs the egr cooler and the air intake manifold. Both can be removed and cleaned. I put an oil catch can on mine to help reduce the build up. Every 10,000 miles, I clean the intake manifold. Every 100,000 I clean the egr cooler. My Prius burns 1qt of oil every 600 miles. More on the highway. You don’t see the smoke because it’s recirculated and burned. I assume it’s has bad rings, but I’ve been running like this for 150,000 miles. NutzAboutBolts has all these how to videos on YouTube to keep your oil guzzling prius going. Good luck. I clean the egr cooler and air intake at the car wash. Just remove the egr valve from the cooler and blast out the cooler at the car wash. Same for air intake, remove sensor and blast it clean at car wash.

 

What weight oil do you use? I have 10 w 40.... I use 1 quart every 6000 and I have 250,000

 

What do you think about using plumber's PTFE tape rather than any kind of chemical sealant?

 

That's not a bad idea. I used permatex 243 (medium strength thread-lock, removable, oil tolerant) with a recent oil catch can install and after cleaning the PCV valve. The valve is still in, and holding tight, no oil bloom.

But I took the OCC apart just a little later, and opted to go with plumbers tape. First off, cleaning off off the Permatex was a pain. I ended up chasing the threads with a knife tip, round and round, it's the only way.

And the permatex was problematic with oil catch can, because many of the fittings are 90 degree elbows. You want them angled a certain way, and if they're tight long before you get to the preferred orientation, it can be very tough, turning them through another revolution, with the NPT thread, which is conical, progressively tightening.

The plumber's tape OTOH, gives the threads a compressible buffer, so they tighten gradually. And it seems to seal well. Only thing, I'm not sure if it can take the temperature, screwed into the engine block.

Hmm, starting to argue with myself here. Maybe permatex for the valve, plumbers tape for OCC's, lol. I believe when you buy the Toyota PCV valve it comes precoated with a thread sealant.

Bottom line: you could install the pcv valve with clean (albeit oily) threads, and the only downside is a slight oil bloom, in my experience..

 

In both cases there (OCC and PCV valve), there is very little gas pressure and no concern for things backing out, but you do need to keep a tight seal to make sure a vacuum leak does not cause running problems.

The Teflon tape should be OK up to about 500*F, which should be fine for just about anything other than exhaust. So it should be fine. I used it on my OCC, and I think I did also on the PCV valve. Service manual spec on the PCV valve is to use some special liquid sealant, which I could tell was on there when I removed mine. It was a clear brittle sealing liquid.

BTW for actual plumbing, where high temperature is not a concern, you might consider Rectorseal No. 5 instead of Teflon tape. In my experience as a homeowner, it never fails, vs. the Teflon tape sometimes will leak a little. Most professional plumbers prefer the Rectorseal as well. The guidance is to use the tape if you need it to be easily removable and not messy, but if it's a one and done install and you can be careful to avoid a little mess, the Rectorseal is the way to go. But the temp spec on that is not as good as the tape, since it's a liquid/paste.

 

Get a New Engine........

 

I’m using BG EPR/MOA preventatively to stay ahead of this issue. There is a post on it being used to restore consumption to more acceptable values.

She Likes to Drink-Should I Get Rid of Her? | Page 2 | PriusChat

There’s also some discussion on the true source of oil consumption being either stuck rings or worn valve guide seals or both. Toyota did update the pistons and rings at the end of this generation Prius and the Corollas with similar 1.8L engines were known to get stuck rings.

valve stem seal DIY | Page 3 | PriusChat

 

My "theory": the stuck piston rings is caused by a combo of:

1. The lightweight, low tensiion piston rings, spec'd by Toyota to get slightly higher mpg, model years 2010 to partway thru 2014. At some point in 2014 they revised the pistons/rings, and the revised parts are spec'd as the cure, in the TSB on excessive oil consumption.
2. Clogging EGR, which will raise combustion chamber temps, which maybe accelerates ring clog up. Third gen was the first to have this style of EGR, and EGR revisions in fourth gen all point to tacit adminsion that the earlier version was not up to the task. 4th gen press releases even mention EGR revision, which seems esoteric stuff for sales brochure material.

 

The one person who pulled the pistons showed a photos of the rings. He said the rings were not sticking.
The photo shows them looking like they are new.
If rings were sticking, or weak, you'd lose compression and notice a lack of power.
It's the valve guide seals....

 

Maybe both?

 

I'd go with a piston soak and engine flush, followed by a full egr system clean also switch up to maybe 5w/30 oil, done this on both my 2010 and 2012 prius and they have 230,000 and 198,000 miles on them and both do not burn more than a 1/2 a quart every 10,000 miles (UK recommended oil change interval).
Ive used liquid Molly engine flush for the piston soak, left it soaking as long as possible (I actually when on holiday) then turned engine over (WITHOUT THE PLUGS IN VERY VERY IMPORTANT to remove any excess chemical from combustion chamber and avoid hydro locking engine) used rest of chemical to do a normal engine flush (you will need to change oil and filter anyway after doing piston soak as chemical leaks past rings into oil) and hopefully this will free of stuck rings.
I now do a engine flush every 3rd oil change (6 months for me) as the chemical is ment to clean around the rings (the piston soak was a one time get it clean first thing) and so far no oil burning issues on either cars.
Also oil is fully synthetic cheapo brand.

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Thought it was oil rings that clogged and stuck

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