2005 Prius and oil issues as of late

Sounds like your car is either leaking or burning oil. Try a different mechanic.

 

Any evidence underneath your usual parking spot of an oil leak? Any evidence of a leak coming out the drain plug? Using conventional 5w-30?

 

Well, if it is not leaking oil, it must be burning oil. At first I thought it might have been underfilled, but 1/4 full after 1000 miles...

Take a look at the spark plugs, If it is burning oil, it'll show up there. If it is guzzling oil that fast, I'd suspect a valve guide.

 

I'll tell you what I think happened.

Since no leaks were found then the most likely situation is that your Prius had initially developed a mild amount of oil consumption. Probably just due to the cars mileage and perhaps exacerbated by the use of an xW20 oil as is fairly common nowdays.

Initially the oil use was probably only 1/2 quart per 1000 mile or less and it could have been managed with a top-up between oil changes or controlled at an even lower consumption rate with a slightly heavier oil. But because at that stage you apparently weren't ever checking the dipstick you drove it with severely compromised lubrication and added a lot more wear to the engine. That's why it's now using at least one quart per 1000 mile.

At this point about all you can do is try switching to a slightly heavier oil and topping it off regularly. Either that or getting a low mileage salvage engine fitted. Find out from the dealer exactly what oil they've been using and tell us where you're located (for climate conditions) and I'll recommend an oil.

 

Hi MM,

Hmm. That is allot of oil consumption for a Prius. Are you seeing black smoke when you accelerate? I was behind a Saab Aerio yesterday, and it was like a destroyer laying down an anti-submarine smoke screen. With the oil your consuming (2 quarts in 1000 miles) you should see similar. Do you see white smoke?

The most common reason for such leakage (assuming you see the black smoke) is valve guide oil leakage. The other common reason is warn cylinder/piston ring interface. White and black smoke might indicated a cracked head or block, and/or blown head gasket.

Are you in Europe where they do the extended oil service periods?

 

Why would the dealer use the incorrect oil viscosity? Even the most shady stealership probably wouldn't risk getting caught doing this.

Severe oil consumption for this Prius is most likely wear related.

My guess is that the dealer changed the air filter at one point but forgot to put in a new air filter. Engines running without an air filter can be damaged rather quickly if driven on dirt roads or during the winter in the great white north when salt is liberally applied to the roads. Either way, once abrasive particles enter the engine intake, piston ring wear and cylinder liner wear occur. The rest is, academic.

The dealer could have caught the error when the OP brought his car in and put a new air filter in the box. Most stealerships would not accept liability for this error since they would have no proof someone else had not taken the filter out at some point after they last serviced it. However, if they had found the air filter was missing, they should have told the OP.

Then again, the engine in this car may just be worn out by no fault of the owner or servicer. 161K miles seems too low to me to have this problem, especially with a Toyota.

It's a shame.

 

There is no "one" correct oil viscosity. Nobody in this thread has suggested that they used the wrong viscosity. I suggested that the oil consumption with 0W20 in a high mileage engine might be higher (than compared with say 5W30). But neither is officially "wrong".

Whatever was the original cause of the oil slowly diminishing over a full oil change interval, there was probably a major amount of wear that occurred after that caused by driving the car down to the zero lubrication point.

 

It seems I misunderstood your point. They way I read it, the OP said he went to the autoparts store, bought and poured three quarts into the engine and went to the dealer the next day. There wouldn't have been any time to use up this oil if the OP had bought the wrong viscosity.

And yeah, I get it. If the OP drove the car without oil for a long enough time, the wear would have accelerated for sure and the engine would undoubtably be fubared for the rest of its life.

The question is did the stealership only put 2 qts in instead of 3.5 during the last service? Let's assume that they're not that incompetent. The OP seems to imply that oil consumption had not been an issue up until the last service. What then are the likely causes for the original decrease in oil level.

Still, I will have to disagree with you regarding viscosity in general. Using SAE20 oil in an engine not designed for it will result in greater wear over time than the same engine that was designed for and tested with SAE30.

The newest engines have gas nitrided oil rails and upper compression rings and often have upper compression rings with thermal spray coatings on the running face instead of nitriding. With the greater wear resistance provided by these rings, these engines can run with thinner oil films and perform acceptably over the 200K miles they are designed for.

Using SAE20 (in an engine manufactured, for example, before the year 2000) for several years is asking for trouble.

 

1. The first problem is that your engine apparently started to consume oil due to the high odometer reading (161K miles) and the associated engine wear, and that you did not notice this until the engine oil level was 3 quarts low. Since the rated capacity is only 3.9 quarts, the oil level was way too low. You should check the engine oil level every other time you purchase gasoline.

2. Lack of sufficient engine oil results in excessive engine wear, so this will cause the engine to continue to consume oil at an even higher rate.

3. I don't know what "1/4 full" means. Does this mean that the oil level on the dipstick appears at 1/4 of the space between the bottom and top dimples on the dipstick? If yes, that means that > 1 quart of oil was consumed since the oil level was near the top dimple after the engine oil change. Approximately 1.6 quarts is represented by the spacing between the two dimples.

4. Given what you reported in #1 above, then it is reasonable that your engine will now consume oil at the rate of > 1 quart per 1,000 miles. Hence you should plan to replenish the oil accordingly and continue to frequently check the dipstick, as the rate of oil consumption may accelerate as the engine continues to wear.

 

No that oil wasn't used up the next day. The OP said it was 1000 miles later that the dipstick was down to about 1/4 full.

Yes and if you keep burning the oil till it's well down off the bottom of the dipstick then you're getting worse and worse condition oil with more and more contaminants in less and less volume. So the substandard lubrication actually starts well before the actual oil light comes on. Of course by the time the oil light comes on then you've got practically no lubrication at all, at least in the top end of the engine (valve guides etc).

For someone who never checks the dipstick the definition of "consumption had not previously been an issue" is usually just that it hasn't yet been run down to completely off the dipstick in one service interval (eg 5000 miles or whatever interval they're using). Often the oil consumption is very gradually increasing over a long period of time as the engine wears but it's just never noticed.

No, there's absolutely no disagreement from me over that one. It's just that xW20 has been approved (retrospectively) for the Gen2 prius in the US. Many people here (this forum) advocate it strongly and recommend it for everyone (with no regard to whether the person is in a hot climate like Southern Texas or whether their engine is high mileage etc.). Yes I personally disagree with this position.

Cars will often show slightly higher oil consumption with one oil compared to another. Cars will start using some oil as they age. Mechanics will sometimes make mistakes and a slight or moderate underfill (or overfill) will sometimes happen. All I'm saying is check your dipstick every now and then people. If you wait until after you've driven it down to zero lubrication then you may never be able to distinguish the original problem from the new problem that you just created for yourself.

 

I agree with you that car owners are their own worst enemies with respect to avoidable engine problems.

Too many people these days think that they don't need to check oil level or tire pressure. There are tire pressure sensors now. Maybe sometime soon some smart individual - say for example a Priuschatter - will design and sell an aftermarket oil level indicator that would let the driver know what the oil level in the crankcase was prior to starting the car after sitting for enough time for the oil to drain back. That way, the car owner wouldn't have to know:

1) how to open the hood (or bonnet as the say in merry old E - I like that term).

2) how to find where the dipstick is located without seeking guidance from the owners manual.

3) how to read a simple gauge - you think I'm kidding that there aren't some Einsteins out there who couldn't properly read one.

 

Well, since we all seem to think the engine is damaged, am I right in thinking that OP will hopefully only need repair of components underneath the engine cover (valves, etc) and not piston or cylinder work ?

As an aside, this thread is a poster boy for checking oil level *before* and after an oil exchange, and keeping a log of consumption.

 

Thanks for reporting back. If it's valve-guides then you could get just the heads reconditioned, but I don't think there's any guarantee that this will solve all the problems. Also the low cost and high availability of low km salvage engines might make it more economical to swap out the entire engine anyway.

If it's not blowing excessive smoke however I think you should at least have a go at just managing it with a slightly heavier oil. (Get the car nicely warmed up and then have someone follow behind you as you drive around and report on whether or not you're blowing excessive smoke. Tell them to pay particular attention to when you're accelerating away from traffic lights etc.)

There are some good high mileage and HDEO's that could really improve the situation. A few that come to mind are :

- Valvoline Maxlife (conventional 10W30)
- Rotella T (10W30)
- Since you're in a warm climate you could even give a 15W40 HDEO like chevron Delo 400 LE a try.

Most importantly check the oil level at least every second gas fill up.

Also be aware that when you've got a "burner" they sometimes burn at a remarkably different rate depending on whether you're driving low speed around town or flogging it at 70+ MPH out on the freeway. You should be particularly vigilant at checking the oil when you're doing high speed freeway miles.

 

A stuck PCV valve will cause high oil consumption and is cheap to replace also check the hose to the valve is not bocked.

 

I do not believe that this is true. It may have been approved by Toyota Canada, but not TMS USA.

There's a big difference between the maximum summer high temperatures that can be expected in Canada vs. the US, so it would be unwise for a US owner to think that the Canadian recommendation applies to the US.

 

^^
How much higher would engine temperatures be if ambient is 90F vs 102F driving highway at 65 mph ? My anecdotal experience is that I have never seen temps on SG over 205F, and that was just before I removed radiator blocking. I can understand that 0w-20 may have an optimal lower ICE temp than 0w-30, but again my experience is that absent blocking, engine temps above 190F are rare, and I think that is without the radiator fan operating. Perhaps my experience is distorted by our dry climate, but I drive 5 mile inclines and still do not see high ICE temperatures.

This is a question, by the way. I don't have a formed opinion other than to try 0w-20 in the winter.

 

A 12 degree F change probably won't matter much. However if you're driving in Death Valley, CA; the Nevada desert; or Phoenix, AZ in the summer then temps might be 120-130 degrees F and that will probably make a difference.

I think that in general it is reasonable to try 0W-20 in the winter with a Prius that has a relatively low odometer reading. My 2004 had an oil consumption problem with that usage as I previously posted; however mpg seemed to improve ~5%.

 

^^ makes sense. I was unclear in my post in trying to say that my guess is that the increased ambient temperature load has to exceed radiator cooling capacity buffer before I would presume a problem with a low weight oil. That said, I only hope for a fuel economy gain from 0w-20 in the winter, so see no good reason to take away increased engine lubrication with 5w-30 in the summer.