Are you guys running a 0W-20 oil or a 5W-20 dino or synthetic. I don't recall ever hearing of a low oil light warning in a TCH before.

 

In my case it is 5W20 dino. It was also 105-degrees, tying an all-time record high for Raleigh/Durham, NC.

 

I often wondered if the huge heat wave was not aided somehow from the large fire, wind blowing east from Colorado. It's possible the jet-stream had lots to do with it.

Ok on the 5W-20 dino oil. I switched to 0W-20 mobil one not long after I bought my 07 TCH which I traded for the new XLE TCH. Anyway I picked up 2 mpg not long after used the 0W-20. The downfall it's it cost $6.47 per quart at walmart. Depending on how many miles on your Camry, might be best to stay with what your using. I seen some switch to synthetic, but were in older cars that then started using half quart between 5000 mile changes. Now sure how that would work on a tight tolerance built toyota engine.

One would think the 0W being a thinner oil would have less oil pressure. Evidently not as the manual recommends using the 0W-20. The reason being it suppose to get up into the valve-train area quicker to help prevent engine wear at startup.

 

5W-20. Not a synthetic oil person. Had a bad experience with it years ago. It was a while ago but still makes me gun shy.

 

Now you got me curious about your bad experience with synthetic. Was is full synthetic and a popular brand-name. Was this on a rather high mileage older car? You don't have to answer unless you want too.

I have seen dino oil engines still running good at 300,000 miles. I ask the fellow driving his old pickup, how often you change oil. He said ever 2000/ 3000 miles and replace the filter every other time. Sorry was years ago, I think it was at 2000 mile intervals. Can you imagine how clean his oil was after 2000 miles.

 

Like I said I was a while (as in a long time ago).
Mobil-1
At that time it was recommended not to introduce synthetic until after the engine has seated (broken in) or about 10K miles. That translated into 18 months for me.
At 10K I switched to Mobil-1 at 30K started burning oil at about 1 quart/K miles.
Dealer determined the valve seals were failing.
Sad part was I don't put a lot of miles on my cars and at 30K the car was over 5 years old so no warranty.
Hyundai gave me a decent trade-in on it.
Big mistake going to a Hyundai at that time.
So I am a Toyota dyno oil person.
I personally would not let my bad experience affect your decision to use or not use synthetic. I am but one anecdotal data point.
I still only put about 6K miles/year on each of my cars so dyno is just fine for me.

As an aside. Back then I stupidly figured using synthetic oil would in some small way reduce our dependence on fossil fuels. Nothing could be further from the truth. Synthetic oil is produced from fossil fuel components. I also believe it uses more energy per quart to produce that dyno.

J

 

To answer one of your original questions, the master caution light came on with the warning. This would be for low oil pressure, low coolant level, low brake fluid level, etc.

The "Check Engine" light in the lower right corner of the dash is your MIL (Malfunction Indicator Lamp) and that will set the code in the computer. These could be emission related (O2 sensor, MAP, TPS, etc), safety related (airbag, seatbelt) or other warnings that will store a code in the ECU. Other systems will also store codes in the BCM and ABS systems as required.

 

Could be the long time ago that the synthetic may not had the additive to make it user friendly to the valve seals.

I started using full synthetic (then was 30 wt) oil back around 1972. I had bought a 71 Olds 98 used with the big 455 V8. Then EON oil by Pacer had been on the market for a few years. It claimed 25,000 mile oil changes but believe me after 10K in those days the engine lost power. A fresh EON oil change sure pepped up the engine. Later I found it used near a quart after many miles, adding a new quart made the engine run so much better. It got to where the usage on the engine cost more than the savings of the longer oil changes. I went back to dyno for many years.

I started back using Pennzoil when they started their super clean your engine advertisements. I think it was the mid 90's I switched and stuck with mobil one due to it's popularity and was recommended by some popular car companies. One of those was BMW.

Even with the synthetic I still did the 5000 mile oil changes with filter. I may go to the new 10K oil changes recommended by Toyota on this new '12 XLE TCH. I will do a few 5K changes till I know it's broke in.

I did change to synthetic at 3000 miles with the '07 TCH. I drove easy to break that car in and it was not fully broke in till it reached 8200 miles due to me switching to syn to early. After the 8200 miles the '07 TCH would then coast like it was on ice, a nice feeling and the mpg jumped about 2 1/2 mpg over my usual 33 mile loop to town and back near daily.

Speaking of seals, Lucas oil conditioner and some high mileage oils such as Castrol have a additive to help swell old gaskets and to soften valve guide seals to prevent oil consumption. I would not use these unless a car had enough oil usage and is over 100K miles.

 

0W20 is not a thinner oil than 5W20 (at engine temperature)...

The first number is how thick the oil is at "winter" conditions (hence the W). It means that it flows at winter conditions just like a 0 Weight oil would flow. The second number relates to the viscosity of the oil at engine temperature. It flows or has the same viscosity as standard 20 wt. oil would.

With a 0W20 oil, you would get thinner oil than 5W20 for at the most 2-3 minutes, until the oils warmed up. Then they would flow the same.

 

What brand oil filter is on the car? What weight oil?

Because the TCH stops and restarts the ICE frequently, it's critical that the oil pressure builds quickly and smoothly. Things that will create problems with this is too-thick oil (mostly at low temps) and oil filter that drains back. An oil pump with excessive clearances will also do that - but you shouldn't see that until well over 200K miles.