View Poll Results: How often do you check your oil?
At every fuel-up or about once a week
3
7.89%
Once or twice a month
4
10.53%
Every few months
8
21.05%
Once a year or so
0
0%
Only immediately following an oil change
8
21.05%
Never
9
23.68%
Only if there is a warning light or strange engine noise
6
15.79%
Voters: 38. You may not vote on this poll
How often do you check your oil?
Lexus Fanatic
Joined: Oct 2003
Posts: 94,223
Likes: 220
From: Virginia/D.C. suburbs
Lexus Champion
Joined: Oct 2002
Posts: 11,204
Likes: 11
From: The Woodlands, TX
I believe 99% of oil filters these days have an anti-drainback valve to PREVENT the oil from draining back down into the oil pan....prevents dry starts.
Lexus Fanatic
Joined: May 2012
Posts: 68,073
Likes: 3,868
From: Maryland
Then you would never be able to check the oil, or change the oil. The oil filter is also not between the oil pan and the engine, oil doesnt drain back through the filter, its pumped through the filter on its way out of the pan into the engine. Oil drains back into the pan when you turn the car off, and when you start it, its pumped out of the pan through the filter into the engine.
That said, as quoted by bagwell from the article he linked: Newer cars with electronic oil level controller will only measure the engine oil when it is warm and stays at a flat surface level. Therefore it’s recommended to check the engine oil when the engine oil is hot. If you check it cold, it will be a slightly different reading from what the electronic controller reports.
Best practice is to see what the manual recommends and follow that. My car's manual says to get the engine to operating temp, shut it off, then take the reading after a few minutes.
Lexus Champion
Joined: Oct 2002
Posts: 11,204
Likes: 11
From: The Woodlands, TX
Then you would never be able to check the oil, or change the oil. The oil filter is also not between the oil pan and the engine, oil doesnt drain back through the filter, its pumped through the filter on its way out of the pan into the engine. Oil drains back into the pan when you turn the car off, and when you start it, its pumped out of the pan through the filter into the engine.
FYI, years ago I swapped from a crap Fram oil filter back to an OEM filter and the engine magically was much quieter on startup, I researched the Fram and the anti-drainback valve was useless on it.....
So it simply retains oil in the filter so it gets to the engine faster on start-up??
Last edited by bagwell; Nov 21, 2019 at 08:29 AM.
Lexus Fanatic
Joined: May 2012
Posts: 68,073
Likes: 3,868
From: Maryland
Here's a discussion of how the oil system works:
https://auto.howstuffworks.com/engin...on-system1.htm
https://auto.howstuffworks.com/engin...on-system1.htm
Let's follow Oliver the Oil Molecule on his journey around the engine!
Oil pan: This is where Oliver hangs out when the engine isn't doing anything; the oil lounge, if you will. In most cars, this pan holds about 4 to 6 quarts of oil.
Pickup tube: When the engine is switched on, it needs oil immediately. Oliver and his oil buddies get sucked up by the pickup tube and lined up for action.
Oil pump: The pump does the sucking so that Oliver can slide up that tube against gravity and then pressurizes the oil. Oliver and his little oil friends get jammed in together even closer. Let's hope Oliver remembered to put on deodorant today.
Pressure relief valve: If Oliver and his friends get too close they start to plan a riot, this relief valve gives them a bit of much-needed breathing space. It's the lubrication system's way of saying, "Settle down, kids."
Oil filter: While Oliver and his friends are allowed to pass into the engine, the filter stops any dirt and debris the oil may have picked up on its last pass through the system.
Spurt holes and galleries: Oliver giggles every time he says "spurt holes." He's really immature. These are the little holes drilled in the crankshaft or other parts of the system that allow the oil to coat the bearings and cylinders that need to stay lubricated.
Sump: After doing his job to keep the moving parts of the engine moving, an exhausted Oliver slides all the way down into the oil pan again, also known as the sump, to hang out until he's sucked back up the pickup tube -- and he's back on the job.
Oil pan: This is where Oliver hangs out when the engine isn't doing anything; the oil lounge, if you will. In most cars, this pan holds about 4 to 6 quarts of oil.
Pickup tube: When the engine is switched on, it needs oil immediately. Oliver and his oil buddies get sucked up by the pickup tube and lined up for action.
Oil pump: The pump does the sucking so that Oliver can slide up that tube against gravity and then pressurizes the oil. Oliver and his little oil friends get jammed in together even closer. Let's hope Oliver remembered to put on deodorant today.
Pressure relief valve: If Oliver and his friends get too close they start to plan a riot, this relief valve gives them a bit of much-needed breathing space. It's the lubrication system's way of saying, "Settle down, kids."
Oil filter: While Oliver and his friends are allowed to pass into the engine, the filter stops any dirt and debris the oil may have picked up on its last pass through the system.
Spurt holes and galleries: Oliver giggles every time he says "spurt holes." He's really immature. These are the little holes drilled in the crankshaft or other parts of the system that allow the oil to coat the bearings and cylinders that need to stay lubricated.
Sump: After doing his job to keep the moving parts of the engine moving, an exhausted Oliver slides all the way down into the oil pan again, also known as the sump, to hang out until he's sucked back up the pickup tube -- and he's back on the job.
Lexus Fanatic
Joined: May 2012
Posts: 68,073
Likes: 3,868
From: Maryland
ahh, I see.
FYI, years ago I swapped from a crap Fram oil filter back to an OEM filter and the engine magically was much quieter on startup, I researched the Fram and the anti-drainback valve was useless on it.....
So it simply retains oil in the filter so it gets to the engine faster on start-up.
FYI, years ago I swapped from a crap Fram oil filter back to an OEM filter and the engine magically was much quieter on startup, I researched the Fram and the anti-drainback valve was useless on it.....
So it simply retains oil in the filter so it gets to the engine faster on start-up.
Lexus Fanatic
Joined: Nov 2011
Posts: 35,285
Likes: 309
From: ON/NY
I agree to just follow the manual. Toyota and Lexus say to warm engine to operating temp. I am not sure how Toyota could possibly be wrong.
Lexus Champion
Joined: Nov 2013
Posts: 13,195
Likes: 1,844
From: WA
In engineering school we were taught to check oil when warm. Overall, I'm not sure it makes that much of a difference. If you're low enough to register low on the dipstick, it'll most likely show up as low either warm or cold.
As with others, the manual in my GS says to check it while warm:
As with others, the manual in my GS says to check it while warm:
■ Checking the engine oil
Park the vehicle on level ground. After warming up the engine and turning it off, wait more than 5 minutes for the oil to drain back into the bottom of the engine.
Holding a rag under the end, pull the dipstick out.
Wipe the dipstick clean.
Reinsert the dipstick fully.
Holding a rag under the end, pull the dipstick out and check the oil level.
Park the vehicle on level ground. After warming up the engine and turning it off, wait more than 5 minutes for the oil to drain back into the bottom of the engine.
Holding a rag under the end, pull the dipstick out.
Wipe the dipstick clean.
Reinsert the dipstick fully.
Holding a rag under the end, pull the dipstick out and check the oil level.
main reason i see they want you to check warm is they want to account for the oil volume that is circulated in the rest of the system from various passages, oil coolers, etc.
Lexus Champion
Joined: Nov 2013
Posts: 13,195
Likes: 1,844
From: WA
If I can remember, this weekend I'll check the oil level in my GS and/or Highlander when they are cold and then when they are warmed up to see if there is any significant (or even noticeable) difference.
