'04 Lexus IS300 question.

[Graham Piccinini]

So over the last year and a half, about 35k miles, that I had owned the Lexus IS300 I have noticed an interesting pattern. Was wondering if anyone here could enlighten me on it. So here it is - on every start the oil light goes off instantly, but a few thousand miles into OCI it stays on for two-three seconds, and then goes away and does not come back on until next start, not even in sharp turns. Then when I check the level it is 3/4 low between "Full" and "Add" marks, which comes up to exactly one quart to get it to full level again.
Now - To the best of my knowledge the oil pressure sensor is located on the oil filter housing and measures the pressure of already filtered oil. So if oil light stays a second or two longer than usual, that means that the oil pressure is not built up. Am I right so far? So how can the oil pressure sensor so accurately know my oil level if it is located AFTER the filter and the oil pick up tube is fully submerged in oil all the time? (6 QUART CAPACITY with an oversized oil filter and filter is always full of oil since it is not upside down) If oil pick up tube is always on the bottom of the oil pan and fully submerged in oil - how does it know how much oil is over it? How does the oil pressure light so accurately (2-3 second illumination of oil light on every start) tells me when I am a quart low??? Sorry, for such questions, but it really "grinds my gears" LOL

 

[Leo99]

You routinely let it get 1 qt low before adding oil?

 

[Graham Piccinini]

Yea, I check it often (on every gas fill up usually or more often) but I don't add oil until it gets to that 1quart distance from the full mark. I just hate having a half quart opened bottle of oil in my trunk. Always afraid of it spilling in my trunk.

 

[Graham Piccinini]

Originally Posted By: Leo99
You routinely let it get 1 qt low before adding oil?
Yea, I check it often (on every gas fill up usually or more often) but I don't add oil until it gets to that 1quart distance from the full mark. I just hate having a half quart opened bottle of oil in my trunk. Always afraid of it spilling in my trunk.

 

[CELICA_XX]

Like most cars, I believe this sensor alerts you to oil pressure, not oil level.

If I'm not mistaken, it's just a conventional oil pressure light

 

[joel95ex]

Originally Posted By: CELICA_XX
Like most cars, I believe this sensor alerts you to oil pressure, not oil level.

If I'm not mistaken, it's just a conventional oil pressure light


yes+1. I believe only a handful of the newest vehicles actually know the level.. likely a pressure switch... try a different filter to see if that helps, but make sure you're not getting low on oil

 

[Vikas]

Interesting observation but you did NOT tell us what happens AFTER you add that extra quart. Does the behavior go back to the way it was when the oil was new and full?

It is highly likely that the oil light is electronically damped so that if it comes on for any reason, it stays on for at least 2-3 seconds so that you will be able to notice it. I believe this is how *I* would do it if I were designing it.

 

[RoadRaceJosh]

The car has an oil level sensor. Do you have an owners manual for the car?

 

[Graham Piccinini]

Originally Posted By: Vikas
Interesting observation but you did NOT tell us what happens AFTER you add that extra quart. Does the behavior go back to the way it was when the oil was new and full?

It is highly likely that the oil light is electronically damped so that if it comes on for any reason, it stays on for at least 2-3 seconds so that you will be able to notice it. I believe this is how *I* would do it if I were designing it.

Sorry about that. After I add the quart - it goes back to normal condition. And normal condition is when the oil light instantly goes off on start up. But then when it get's to 1qt low condition - it goes back to 2-3 second oil light illumination delay after every start up until I top it off.

 

[Graham Piccinini]

Originally Posted By: Joshua_Skinner
The car has an oil level sensor. Do you have an owners manual for the car?

I got the owners manual, did not find anything in it that would explain such behavior... Maybe the Maintenance manual could give some info, but I don't have it.

 

[Graham Piccinini]

Originally Posted By: Vikas

It is highly likely that the oil light is electronically damped so that if it comes on for any reason, it stays on for at least 2-3 seconds so that you will be able to notice it. I believe this is how *I* would do it if I were designing it.

That's what I think it is, and seems logical. Just can't understand how the oil pressure sensor, that is located after the fully oil filled filter, could know the oil level in the oil pan.

 

[Vikas]

Is the filter bleeding off more when you are low on oil? Does it happen on all type of oil filters? Have you tried different oil filters?

 

[Graham Piccinini]

Originally Posted By: Vikas
Is the filter bleeding off more when you are low on oil? Does it happen on all type of oil filters? Have you tried different oil filters?


So far it is the same on all filters that I have tried. Fram Ultra, old PureOnes, STP Extended Life Filter, Mobil 1 filter, genuine Toyota filter, and Fram tough guard are the ones I tried so far.

 

[CELICA_XX]

Well I stand corrected... this car has a standard oil pressure light as well as an oil level light.

Originally Posted By: Lexus Owners Manual
Low Engine Oil Level Warning Light:

While driving on steep inclines or rough roads which causes
the vehicle to substantially sway or on curves, this light may
come on due to the movement of engine oil in the engine.

In normal conditions, due to engine oil consumption, this light
may come on earlier than the specified service interval of the
scheduled maintenance. This is because the engine oil is
consumed to the low level within the scheduled maintenance
interval and does not indicate a problem.





Also, apparently there is a 1.9 quart difference between LOW and FULL on your dipstick.
(page 334 of your owners manual)

 

[Graham Piccinini]

Originally Posted By: CELICA_XX
Well I stand corrected... this car has a standard oil pressure light as well as an oil level light.

Originally Posted By: Lexus Owners Manual
Low Engine Oil Level Warning Light:

While driving on steep inclines or rough roads which causes
the vehicle to substantially sway or on curves, this light may
come on due to the movement of engine oil in the engine.

In normal conditions, due to engine oil consumption, this light
may come on earlier than the specified service interval of the
scheduled maintenance. This is because the engine oil is
consumed to the low level within the scheduled maintenance
interval and does not indicate a problem.





Also, apparently there is a 1.9 quart difference between LOW and FULL on your dipstick.
(page 334 of your owners manual)



Thank you!!! My owners manual does not have any of that... Not even page 334 lol. Probably due to the fact that I downloaded it from some shady website... The vehicle did not have an owners manual with it, so I just downloaded the first thing I could find just to get fluid capacities and stuff. Thanks a lot!!!

 

[Graham Piccinini]

But the light never ever came no matter how sharp the turn or rough the road that I am on... Just on start ups when it's a quart low. Anyways, thanks for replies everyone!

 

[SatinSilver]

What brand and weight oil are you using? What brand and model oil filter are you currently using? At least the oem ones have a very good flow rate and are quality built to last the full oci. Filtration is very good as well per a uoa after 10k miles on the 2012 Camry.

 

[Vikas]

Are you parked on the sloping driveway?

 

[Graham Piccinini]

Originally Posted By: SatinSilver
What brand and weight oil are you using? What brand and model oil filter are you currently using? At least the oem ones have a very good flow rate and are quality built to last the full oci. Filtration is very good as well per a uoa after 10k miles on the 2012 Camry.


Right after this OCI it will be Pennzoil SRT 0w40 and Fram Ultra and then Bosch Distance+ oil filters. And what I have now in the sump is discussed above.

 

[Graham Piccinini]

Originally Posted By: Vikas
Are you parked on the sloping driveway?


My driveway is at a nearly 35-40 degree angle. But my garage floor is straight as an arrow. That is one of the proven leveled spots where I check my oil levels.