I have an 86 Camry LE with 91k miles. When it has been sitting for a number of hours (typically overnight), it takes about 15 second for the oil light to go out when I start it. The light never comes back on while driving, and if I stop the car for a few minutes, like when getting gas, the light goes out almost immediately when I start the car back up.

This is like when you start your car the first time after changing the oil filter - it takes longer because the pump has to pump a lot of oil into the new filter. In fact, this started not long after the last time I changed the filter.

Is there some kind of check valve in the system or the filter that is supposed to prevent all the oil from draining back into the sump? This could explain the problem, I suppose. Or is there probably something more seriously wrong with the oil pump?

In the meantime, am I destroying the engine? I never run up the RPM when this happens - I always leave at idle until the light goes out.

Thanks for any info.

 

It could be a number of different things. Your losing oil pressure . Id 1st start by making sure you have no oil leaks. If your leaking oil see where its coming from . That could be a good indicator. It could be that your oil filter or drain plug isnt tighten down all the way perhaps making it lose oil pressure.. But that would also mean you have oil leaking somwhere.
It also could be to thick of a cold weight oil...Example. I have a 02 f-250 5.4v8..The oil says use 5-20 w oil. I use it and even after its been sitting over night it will knock for about 2-5 seconds and then run perfectly fine.. Never once knocking agian . Now i use 5w20 oil and it still does that. Im guessing all the oil is drained to the bottom of the pan and needs to fit thru oil valve clearances to reach the top of the motor and lube and stop the knocking. Now if i used 10w30 or 10w40 the knock would be longer 5-8seconds usually till the oil reaches the top of the motor to rid the knocking sounds. If i used 20w50 my engine would blow up on a cold start.
Perhaps your using to heavy of and oil for a cold start..If you live up north you should use a 5w30 or 5w40 oil being that the cold weight is lighter as opposed to 10w30 or 15w40 ect. It will circulate better at cold temps hopefully resulting in quicker lube, and just maybe stop making your light do this.
Keep in mind when you 1st start a cold engine it takes a couple of seconds to circulate the oil to build pressure.
It could also be something more serious such as a lifter, bad pump...It all depends..Id just start with the basics and see what your overlooking..Perhaps the oil ...The way your parked on a hill maybe. Not sure just my .02$

 

Try to check i guess there is an oil switch or sensor ... replace it with another 1 if possible .. am not so sure but sometimes its a small thing that cause u to go through a long process that end u wasting alot of money.

all the best

 

Hey dbarstow,
I'm a new member but not new to cars, the guys ahead of me gave you good info. But you stated you noticed the problem started after an oil change. Here's some cheap advice. Pull the filter and install a new one and top off the oil. Filters like any other product are manufactured and you could have a bad one. If it still takes 15 seconds. My further advice would be to talk to a knowledgeable guy at your favorite parts store and pour some engine cleaner into your oil, idle for 10 minutes and change the oil again. You've got 91,000 miles on a 21 year old car. I bet the oil sat in that crankcase awhile from time to time. It could be your oil pump screen ispartially clogged up. You might just have noticed after the last oil change as a coincidence. In my younger years, many great mechanics would pour about 1/2 quart of diesel or auto transmission fluid into the crankcase immediately before the oil change and idle the car for 10 minutes. Much higher detergent factor. Even the Ferrari guys. Sounds nuts but check it out on the web. But remember, just idle the car, no test drives after the engine cleaner, the oil is very thin and will not supply the protection your engine needs for any higher RPM stuff, the oil will come out very black too.

Check it out quickly and don't screw around with low oil pressure, because that's what you've got...unless a bad sensor, sending unit, as above. It's my 2 cents anyway.

 

there are definately oil filters with aintidrainback valves, probably half/most of the ones sold on the market have them, but not all. however i somehow doubt that is what triggers your light if its been happening for a while.