One for the Experts - Only (Oil usage)

Difficult to believe you went from 0 to 1.5 quarts per 5000 miles that quickly. All engines that are functioning properly will use a small amount of oil over 5000 miles. Those who claim their engines don't consume "a drop" of oil after 10,000 miles have an oil dilution problem, drive like grandmas, or are out and out liars.

I don't buy the stuck oil ring theory. If the two oil rails and expander were stuck your oil consumption would be much greater - 1 qt per 1000 miles at least. The UCR, LCR, and OCR all rotate in the piston ring grooves while the piston travels along the bore. If the OCR stuck in the third groove, the affected cylinder (s) would not be able to scrape the oil off the liner properly and would cause consumption to a degree you're lucky not to have.

Your answer is somewhere else. I wish I could tell you where you should be looking.

You should switch to a full synthetic oil to see if the consumption decreases. At least you'll have a hint of where you need to look to find the root cause.

 

I agree with the mechanic. Bargain oil is really bad for a modern engine.

 

Unusual for Edthefox5 and I to agree, but bargain oil is not a bargain in the Prius engine. An oil additive is worth trying then go to a good quality oil and keep a close check on the oil level.

 

Hey even a busted clock is right twice a day!

 

Last time I agreed with you both our posts were taken down.

 

Well since Ed and Brit's posts are going to be removed, leaving a near-empty discussion, I thought I'd chime in despite my less than expert knowledge. If this is chronic problem (no quick solution) you might want to consider Mobil-1 5w-30 High Mileage Formula which is formulated to mininize oil losses.

 

Less oil consumption is always nice and we have come to expect close to zero oil consumption on late model engines. But, one quart per 3300 miles in itself is not a problem although it may be an indication of a problem starting. It's not enough to mess up your emission control system and shouldn't make a visible amount of smoke. If you took a car still on warranty into a dealer and tried to make a warranty claim for that level of oil consumption, they would laugh at you, maybe not to your face, but they would laugh at you.

PCV valves and rings can get cruddy and not completely stick but still not work as well as they should. Also, sudden changes in oil consumption aren't rare, that's why y0u should still check your oil level on a regular basis even if you have close to zero consumption

A reasonable amount of MMO before an oil change -might- help. Just don't run your engine hard or get it too hot while running that diluted mix.

You should also start using good oil.

 

I'd be very interested to see how the tiny and very fine VVT oil filter faired and if its clogged after a lifetime of crapo oil.
This filter makes sure the oil that drives the variable valve timing advance sprocket is clean. This filter is found behind a hex head bolt about 3 inches below cyl #1 intake manifold. If interested search back my old posts as I have a detailed write up about it. You need a hex head socket and a breaker bar to get that bolt out as its really in there.

 

...was wondering if the oil loss shows up on emissions testing, OP and I are in VA which exempts certain Prius model years (incl. 2006) from emissions testing. Saves me $15 every 2 years but if there is a problem might not see it.

 

You know, one possibility is that your luck with bargain oils eventually just ran out. There's a guy (Tom NJ) who often posts over at *BITOG on behalf of an organization (PQIA) that does independent testing of many brands of oil in a US market. Particularly "bargain" and unknown brands. While these oils frequently pass all the tests there are still many that don't and sometimes they fail in an absolutely alarming way, like having severe contamination or absolutely no anti-wear additives for example. This situation just never happens with any of the major brands they test (like Castrol, Mobil, Shell, Penzoil, Valvaline etc), so it does make you realize that it is a lottery when you use a cheap unknown brand of oil.

Here's just a few ones they've "outed" lately. Over the past year or so Tom has post many fails like this, some even worse.

Petroleum Quality Institute of America
Petroleum Quality Institute of America

* PQIA Issues Consumer Alerts on Auto Club oil & ATF - Bob Is The Oil Guy

 

I had a similar oil consumption spike, but much worse - more than a quart every 1000 miles

I used dino oil for 5k changes with some out to 7k until my extended warranty ran out at 70k. Never a drop was used early on and I got complacent and didn't check until the oil change. I even filled the oil low figuring it would warm up faster. At 70k I changed to Mobil1 Extended Performance so I could stretch out to 15k OCI. After a few thousand miles, I checked before a trip to Disneyland and noticed nothing on the dipstick. I added a quart and got it about halfway between the full and add dimples. 800 miles later - nothing on the dipstick.

Did a lot of research - here are two posts by toyota mechanics
Gen II Burning Oil? | Page 2 | PriusChat

Help me choose oil for 1998 toyota corolla! - Bob Is The Oil Guy

Note that corolla 1.8 engines are very similar to Prius 1.5

I tried the Auto-RX and it must have popped the oil control ring free within the first 500 miles and was back to 1qt per 3000 miles. Second treatment and I'm at 1qt per 3500 miles. Gonna try the third treatment with Mobil1 EP for the full 15k miles. A friend tried it in his son's certified used car purchase and now it can make it for the full OCI without adding oil.

Many people think Auto-RX is snake oil for sludge, but for compression and rings, there seems to be less controversy

I plan on using ACEA rated oil from now on

Hope this helps
Ray

 

Yes, the oil rings are "seized" or "stuck".. Adding a can of Rislone to the oil (after having drained 1 qt first) & drive the car 3k before you drain & refill.

Been there, and done that with my previous car. It ran perfectly with no noticeable consumption until 120k & all the sudden it started consuming 1/2 qt every 1k.

Reason I recommend 3k interval is to safe guard against "sludge". In case there's any sludge built up in the engine, best practice would be draining the oil out at short invervals & repeat the Rislone process until you'd freeup the rings & removed all sludge.

Not a big deal & I wouldn't lose any sleep over it. But get the Rislone in the engine ASAP. It worked beautifully for my 04 TL & I drove that car another 40-45k "without" any oil consumption before the transmission went out at 160k.

IMO you should stick to quality name brand oil. Everything in our capitalistic society sells for what it is worth so for the most part you will get what you pay for. Don't be penny wise & pound foolish on bargain oil, quality motor oil is cheap insurance. I really like Toyota's 0w/20 synthetic in my GenII, it gets dirty the fastest amongs all the oil I've tried. Getting dirty quickly indicates that the oil has strong detergent/additives & consequently keeping the contaminants & all the combustion by-product from building up inside the engine.

So far it hasn't show any signs of oil consumption in between oil changes either. After my existing case runs out I plan on switch to Royal Purple, just to compare the differences.

 

For the last four months or so my 2008 Prius has been using two extra courts every 5000 miles. I have a long commute to and from work so my milage is up above 90,000 at this point. I have not been using cheap oil. I've had it checked for leaks, but none found. Dealership mechanic says it's been burning oil, but I haven't seen any blue smoke. Any comments?

 

If you want to go cheap with oil, go to Walmart and buy the SuperTech brand (Walmart's store brand). It's about as cheap as you can get and still have an acceptable oil quality-wise. The Purolator Classic oil filter Walmart now sells as their "value" product (in the place of the SuperTech filters) are arguably better than the two lowest quality Fram filters (Extra Guard and Tough Guard), and the Purolators cost about a dollar less than the Fram Extra Guard (aka orange can of death).

What I did a few months back to save a few bucks was buy a case of Napa Synthetic on sale for $3.99 a quart. It's normally $5.99 a quart. Napa Synthetic is made by Ashland, which makes Vavoline products, and is the same as Vavoline Synpower but with a lighter additive package. Other than that, I'll buy the 5qt jug of Synpower at Walmart for $26.00. And the Purolator Classic will be fine unless you're doing extended oil change intervals.

If you want to blow hours of our life researching motor oils and filters, go to bobistheoilguy.com...

Scott

 

Try put a quart of Rislone with your next oil change, or simply just drain 1 qt out of existing oil & add Rislone if you like. But I wasn't a believer of Rislone until I took a leap of faith few years ago as I have nothing to lose & it worked for my 04 Acura TL which had 120k at the time, it was consuming 1/2 qt every 1000 miles out of the blue but Rislone fixed it after 3k.

 

What do you mean "bargain oils"? Many great petro oils can be bought on sale at bargain prices. If you only used oils rated SM or SN (or what ever was current the year you bought the oil...say, what year is your Prius anyway?) with names like Shell, Pennzoil, Mobil, Havoline etc.. you should not be having oil related problems.

But, if you bought convenience store oils, some which are non detergent or have very low additive content, then that could be a problem. These oils will have names not associated with any major oil company.

 

I'd really like to hear from someone on this. Burning two quarts every 5000 miles to me seems a bit much. Can anyone tell me what is going on and what I should do about it?

 

Have a look at the first link in post #12 above. Sounds plausible to me.

 

Read the links in my post above

Use something to free the oil control rings - Auto-RX, Techron, Marvel Mystery Oil, Kreen, Rislone...

Each remedy has its fans and critics. I have an 80 mile R/T commute almost all highway and mine cleared by the end of the first tank with Auto-RX. Techron was recommended by a Prius Tech for 5 consecutive tanks - I believe I read something during my research that testing in the 70's of Techron thickened the oil after several consecutive treatments. I only use it in the tank before I do an oil change. MMO/Gunk Flush are basically like kerosene and thin the oil - not my thing. Kreen is receiving rave reviews on Bob is the Oil Guy forum.

Do your own research and pick your poison