MR2turbo

I bought a 2000 LS400 a few months ago. The car has about 125,000 miles on it. I didn't know what kind of oil the previous owner used, and seeing as how the winter temperatures in Canada can be brutal, I replaced the oil with 5W-30 Castrol Edge full synthetic about a month ago, about 1,000 miles ahead of schedule.

Approxmiately 2 weeks ago I forgot to plug the block heater in overnight. The weather was extremely cold and when I started the engine in the morning to go to work, the oil pressure warning message was displayed. I thought the oil couldn't be pumped properly as it was too thick due to the cold temperatures. To play it safe I shut off the engine and got a ride to work. I plugged the car in overnight and didn't have the same issue.

Fast foward to yesterday. The temperatures have gotten quite a bit milder. I drove my car home from town. The engine was fully warmed up according to the temperature gauge. After making a small u-turn my check engine and vsc off lights came on. The engine continued to run fine. I drove home, disconnected one of the battery terminals and thereby reset the ECU. After that the light haven't come on yet, but I've only driven the car approximately 15miles since.

This morning I started the car (32 degrees fahrenheit, block heater not plugged in) and the oil pressure light came in, however disappeared after a few seconds. No other lights were displayed.

Has anybody had a similar experience? I did some research and found out that the vsc + engine light can be a faulty oil sensor. Can somone please tell me where I can find this sensor on the 1UZ-FE engine. Also, how do I check the oil pressure? Please help! Thanks in advance!

timmy0tool

iTrader: (7)

i'll state the obvious and say did you check your oil level?

i am unsure of weather related conditions since i live in milder climates but if your area necessitates a block heater, oil weight and antifreeze should be taken seriously. i am leaning towards a faulty oil pressure sensor. can someone with a repair manual help on it's location?

LScowboyLS

I will also state the obvious, why are you not using a 0W-30 weight oil for Canada's brutal winters?

Your oil warning light can come on for a number of reasons including: low oil level, a failing oil pump, a faulty oil-pressure sensor, blockage in the oil system, or excessive foaming of the oil, among others.

MR2turbo

Yes, the oil level is the first thing I checked. It's exactly at the full mark, not below and not above it. I've used 5W-30 on my previous vehicles without any problems.

Wondering if someone knows the location of the oil pressure sensor. I don't have a heated garage and would really like to avoid crawling around underneith the vehicle trying to find it.

Another question, what should the normal idle speed are you getting on your LS400s after the engine has warmed up and the transmission is in drive? I noticed today that the rpms were at 500 or even slighly less. Wondering if that's normal.

Thanks again!

LScowboyLS

650

low idle can be caused by many things, dirty throttle body, TPS or throttle cable set incorrectly, Idle Air Control Valve, vacuum leaks, ignition timing, dirty injectors or even failing ECU capacitors


are you getting the red (pressure) or orange (level) oil light?

PureDrifter

iTrader: (10)

~600-650 +/- 100rpm when warmed up, AC off, and in Neutral or Park.

Yamae

The oil pressure sensor is located at the oil filter base.

MR2turbo

LSCowboyLS: I'm getting the red "oil pressure" warning in the morning on startup, but it disappears after a few seconds.

Yamae: Thanks a lot for the help! I appreciate it!

Puredrifter: Mine is at about 500-550 when warm, and at the 400rpm mark when in "D". I'm assuming this is too low, correct? I don't think the rpms were this low before I started having the check engine light + vsc issue.

PureDrifter

iTrader: (10)

not too far off, it's within the correct range. Cleaning the throttle body and idle ports would probably bump it up that last hundred RPM or so.

MR2turbo

Alright, I have an update. All issues have been resolved
It turned out to be a faulty or incorrect oil filter.

I started receiving the low oil pressure warning more frequently. I replaced the WIX oil filter which I installed several weeks ago when I completed my last oil change with a cheap unit from Canadian Tire. The oil pressure problem went away immediately and after a few drives the check engine + VSC off lights turned off by themselves. Even the idle speed is now slighly higher and within spec.

I still brought the vehicle to a shop this morning. The mechanic checked codes that were still saved in the ECU and they turned out to be P1349 & P1354, both related to the VVT-i system. Since the VVT system is regulated with oil pressure it would make sense that the computer threw codes.

I'm still planning on taking the oil filter appart to see what went wrong, however I will NEVER again use non-OEM oil filters. I usually always use OEM filters, however hadn't been at the Toyota dealer since I bought the LS as it's 80 miles away.
Lesson learned. Hopefully I didn't do any permanent damage to the engine.

Yamae

Thanks for the update. Congratulations on your success finding the root cause.

I was worrying about you and my engine oil because what you have used was something similar to mine.
I use the engine oil shown below. It doesn't say, "Castrol Edge." But I explain why.

It says,"Exclusively for sale in the Toyota network." According to the dealer's manager, it is very similar to Castrol Edge but this is exclusively available only at Toyota dealers in Japan. The manager said, "Castrol T-Line is derived from Castrol Edge and specially tuned to meet the requirements of Toyota.

Then I asked him the evidence of it and what he did was to show me the internal documents. After reading it, I understood what he said was mostly correct. The documents said, "To meet the requirements of Toyota dealers." It's not Toyota but Toyota dealers.

It is not as expensive as Castrol Edge obtained at shops. Problem is that you have to keep it at the dealer for minimum 20L and the oil change is only done at the dealer but the fee to change is none as long as the customer keep it 20L or more. So overall payment is a bit less compared with doing everything myself buying the oil at shops.

I decided to try to use it and I have been happy with the good performance of it so far. Then all of the sudden I encountered this thread and I just wondered, "Should I keep using this?"

Now I will be using this since it is one of the best both in cold winter and in extremely warm summer here at near Toyota Japan, I find so far.

MR2turbo

That's interesting. I've been using Castrol oil in all of my vehicles for the last 10+ years. Regular Castrol GTX in the "beaters" and Castrol Synthetic in the vehicles I care about. My mom's Corolla has gotten 5W-30 Castrol GTX oil changes since we bought it about 6 years ago and has handled our -30 degree celsius winters and +35 degree celsius summers without issues. I think you should be fine using 5W-30 all year round, especially if it's synthetic.