Oil loss

Common for high mileage Prius.use thicker weight oil to slow the burning

 

In 2014 model year Toyota revised the pistons, and in 2015 they also revised the piston rings:



Replacement of earlier year 3rd gen Prius with the 2015 pistons and rings is the fix, at least as described in this pair of technical service bulletins. The first document entails an oil consumption test, which requires consumption of one quart or more, in 1100~1300 miles, for you to qualify for the piston/ring replacement.

Unfortunately, the vehicle must also be less than 60K miles, which is a bit of an absurd Catch-22, since this consumption seems to be manifesting at somewhat higher miles, in most cases. Still, an interesting read, and just maybe Toyota makes acceptions, either full or partial, for higher mileage cases? It doesn't hurt to ask.

Reading through the second TSB might give some idea about the cost to repair. Mention that TSB to a dealership for reference: ask for a quote. Here's a breakdown of the parts (mandatory parts, listed in the TSB):



(There are also some discretionary parts, that may or may not be needed. Replacement head bolts for example, presumably only required if the original bolts are distorted beyond the Repair Manual spec's, for max length, min diameter. To be on the safe side they could be replaced in any event, and that would add about $100.)

The TSB also budgets 16 hours of labour, fwiw.

Also consider doing a full clean of the Exhaust Gas Recirculation circuit, and the intake manifold, and an Oil Catch Can install on the Positive Crankcase Ventilation line, between PCV valve and intake manifold. Watch @NutzAboutBolts for info on all these, linked in thread at top of third gen maintenance forum.

Maybe also: do a rough calc to determine the miles per quart (not just months), for a better picture.

Just out of curiousity: what oil have you been using (weight/make), and at what interval (10K miles, or)?

 

Maybe a good time to do this when the head gasket goes bad.

 

Yeah, a head gasket is included in that gasket kit, I'm pretty sure. Along with pretty much every gasket, judging from some EBay pictures. I'd really like to see a complete list of what's in that kit, and so far have drawn a blank.

FWIW, just the head gasket through McGeorge is something like $47. That and a tube of the specd form-a-gasket would all that's needed for a head gasket change (assuming head bolts still within specs), and you don't even need a hoist for that.

 

or both

 

or maybe it's the only way to squeeze out 50 mpg

 

How thick? I use OW20 syn and will add 5 qt between changes. I recently changed my plugs and they showed no signs of burning oil.

 

how many miles on her? have you cleaned the egr circuit?

 

5w30

 

How or where do you check the plugs to see if it burns oil?

 

This is a resurrected thread but I would still like to chime in cause I think my experience is important to others. When I did the head gasket on a gen 3 I followed all the information on the site and bought rings and swapped them out. Problem is, they were perfect, not clogged at all. The old ones looked as good as the new ones, a total waste of time. I kept thinking maybe the next one is clogged, but never got to one even slightly clogged. The picture below is 200k parts. I did swap out the rings cause I bought them, and I was already there. Just remember the deeper into an engine you go the more likely you are to screw something up. Its not always you, its metal. Broken bolts, stripped holes just "stuff". I recommend if you don't have a blown head gasket you start with rislone engine treatment. Its 6 bucks, works slow and cleans that stuff out. Certainly worth the money. And if you didn't do your EGR and your over 100k better get it done. Best is to buy a used egr off ebay and clean and clean and clean till you can see through all the holes. Then take the car apart on the weekend and swap yours out with the now clean and dry ebay part.

 

Thanks! You are the first one, that I've seen, who has done this. Everyone says the rings get clogged
and stick. But from my experience, if that happens, the car has very poor performance.
I believe it's the valve guide seals that leak. Mercedes had this problem back in the late 80's.
And I've replaced them on other vehicles and resolved the oil burning problem.

Thanks again!

 

Wow, that is interesting. That piston looks brand new. How much oil were you burning?

Had you been doing or had done the rislone treatment?

How were the valves?

 

Borgestes, you are so right about big engine work. What starts out as simple, always winds up with a stupid bolt or frozen nut causing a slow down in the process. Thank you for showing us your discovery! I'm at 48k on my 2015 and my next goal is installing the Oil Catch system. At 100k, I am buying a used egr and will soak and clean it, then its off to Hybrid Pit for the install. Thanks Again!

 

I bought this car with a blown head gasket. So I don't know much about it. But everyone talks rings are clogged on gen 3 so I just assumed. I assumed wrong. Luckily it appears that I did the job correctly cause I believe my buddy is at 30k since the rering job. As far as the valves, I send the head to the machine shop I have dealt with for 20 years and pass them the valve stem seals and tell him to fix it. I come back and he gives me a bill. I don't ask questions. he always does it right, and I always pay him. Its a great relationship.

On the buying the spare off ebay, take your time, get the part number and set up a search for it. When someone posts one grab it. I cant believe they want 150 for a used egr. That's like crack head pricing, then you gotta pay tax on it now. You got to be kidding me. The dealer wont clean it, they just replace. Here is a 1200 dollar bill for just parts to replace the egr on my car. The guy who sold it to me paid it. I bet the tech turns around and sells the dirty one on ebay.

 

I bought my spare EGR cooler from a junk yard I found online. $50, free shipping.
It was pretty clean, just sooty. I was surprised. When I pressure washed my house a month or so back,
I sprayed out the cooler. It does look cleaner, but I'm going to soak it with oven cleaner, then
pressure wash it again.
If you search enough, you could find a good price for a cooler...
You should always ask for your old parts back....

 

@ borgestes...Did you mic the pistons/bores and check the old/new ring gaps while it was apart?

 

I just checked the ring gaps on the new and put it back together. I had no intention of replacing anything else including rod bearings or anything else. Like I said, I shouldn't have even been there. If anyone gets the mad desire to rering a gen 3 engine, know that it is put together by robots that squirt gasket goo in the perfect amount in the perfect location. There are few gasket seals you have to use the similar goo to get it back together. Too much it falls off in the engine blocking oil passageways, too little and it leaks.