IS - 3rd Gen (2014-present) Discussion about the 2014+ model IS models

Checking engine oil levels - cold or warm?

Thread Tools
 
Search this Thread
 
Old May 24, 2020 | 06:52 PM
  #1  
spindos's Avatar
spindos
Thread Starter
Driver School Candidate
 
Joined: Mar 2019
Posts: 47
Likes: 2
From: CA
Thumbs up Checking engine oil levels - cold or warm?

Do I measure oil levels when the engine is cold or warm?

Our owner's handbook doesn't have any specific instructions on checking the engine oil while the engine is warm or cold.

As far as I'm aware, some of the newer cars with electronically controlled oil level modules require that all checks be done while the oil levels are worm.

Also, has anyone over filled on oil and ever dealt with a burning oil smell coming from the engine bay after?
Reply
Old May 24, 2020 | 10:14 PM
  #2  
arentz07's Avatar
arentz07
Moderator
5 Year Member
Shutterbug
Community Influencer
Community Favorite
 
Joined: Nov 2016
Posts: 9,598
Likes: 4,787
From: GA
Default

Originally Posted by spindos
Do I measure oil levels when the engine is cold or warm?

Our owner's handbook doesn't have any specific instructions on checking the engine oil while the engine is warm or cold.

As far as I'm aware, some of the newer cars with electronically controlled oil level modules require that all checks be done while the oil levels are worm.

Also, has anyone over filled on oil and ever dealt with a burning oil smell coming from the engine bay after?
Most of the advice I've heard is to check when cold. I think your owner's manual would state otherwise if applicable - sounds like not so much in this case. If I check warm on my car, I get a very different reading from cold. I always checked my IS when cold and got plausible results.

If you overfilled the oil, might be a good idea to drain off the excess ASAP. Overfilled oil seems like a bad thing though I only have my Googling as far as knowledge on that topic.
Reply
Old May 24, 2020 | 10:48 PM
  #3  
Flash5's Avatar
Flash5
Pole Position
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2018
Posts: 2,626
Likes: 459
From: GA
Default

The most "basic" answer would be to run your car for a few minutes then wait about 15-20 minutes for the oil to settle then check it. I personally check it when I wake up and it's cold then another time after driving it and then letting it sit for about 20ish minutes. I obviously only check it like every other week if that.
Reply
Old May 25, 2020 | 09:31 AM
  #4  
HOMER350's Avatar
HOMER350
Racer
 
Joined: Mar 2018
Posts: 1,589
Likes: 317
From: SoCal
Default

I think its normally suggested to check when warm. However I've always checked when cold. If doing an oil change I check cold, start the car let it idle like a min or so, check again. If you're checking warm after a drive probably give it a few mins to settle before checking and it should be reading higher warm than when cold. Thats why if I ever feel the need to check when warm I always check again later when cold.
Just my theory. I really don't know what the experts say should check that out lol.

But more importantly if you're too full on oil you want to fix that like today. I too would have to Google the reasons right now but trust me they're valid I've seen a few of them come to life. Depending on how much its not something you want to leave let your car work out on its own.
Reply
Old May 25, 2020 | 10:12 AM
  #5  
Sasnuke's Avatar
Sasnuke
Lexus Test Driver
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2017
Posts: 6,260
Likes: 1,752
From: Richmond Hill, Ontario, Canada
Default

For me ideally checking when it's cold is the way to go.
At that point the filter should be full, a film of oil all over the engine interior, and the rest of the oil collected in the pan.

After an oil change I will start the car, and once the oil light goes out, shut it off. If you're lucky that should be about 3 seconds at most.
Then I check the oil level.
Once again at that point the new filter should be full and the oil distributed throughout the engine to coat everything, and the rest sitting in the pan.
This is assuming too that I warmed the engine up before the oil change.
Reply
Old May 25, 2020 | 01:33 PM
  #6  
NickCaesar's Avatar
NickCaesar
Instructor
 
Joined: Jan 2019
Posts: 853
Likes: 175
From: Ontario
Default

Originally Posted by spindos
Do I measure oil levels when the engine is cold or warm?

Our owner's handbook doesn't have any specific instructions on checking the engine oil while the engine is warm or cold.

As far as I'm aware, some of the newer cars with electronically controlled oil level modules require that all checks be done while the oil levels are worm.

Also, has anyone over filled on oil and ever dealt with a burning oil smell coming from the engine bay after?
My mechanic accidentally slightly overfilled my 350...he put like 7.2 qts instead of the 6.5 or whatever it calls for. What I did was take a thin rubber hose,put it down the dipstick tube and siphoned out a half quart. Don’t do it when oils hot, but it worked perfectly for me and is easier than lifting car up and draining.
Reply
Old May 26, 2020 | 10:23 AM
  #7  
E46CT's Avatar
E46CT
Lexus Test Driver
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2016
Posts: 9,523
Likes: 2,582
Default

Half a quart isn't anything to worry about. You'd get higher levels of sloshing from just sitting in your car or going over a speed bump. I verified this back in the day by pulling the oil pans and doing some measurements because this same thing used to float around before.

In fact, some of the BMW track guys used to over fill by 1-2 quarts on purpose back in the day. I did on two of my M3s. They did that for a decade or more. So 1/2 quart isn't a big deal. If all it took was a 1/2 quart to make or break you, you'd total your engines every time you took a turn. The engine is a very dynamic violent place. And yes i'm well aware of crank aeration.

As far as when to check it, best to check when warm and after the engine has been shut down. Depends how the dip stick was designed to be calibrated.

Though at the end of the day, a dangerously low oil level will be low regardless of the temp of the oil. And of course no oil will always be no oil. So check whenever.
Reply
Old May 27, 2020 | 06:00 AM
  #8  
Sasnuke's Avatar
Sasnuke
Lexus Test Driver
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2017
Posts: 6,260
Likes: 1,752
From: Richmond Hill, Ontario, Canada
Default

Originally Posted by E46CT
Half a quart isn't anything to worry about. You'd get higher levels of sloshing from just sitting in your car or going over a speed bump. I verified this back in the day by pulling the oil pans and doing some measurements because this same thing used to float around before.

In fact, some of the BMW track guys used to over fill by 1-2 quarts on purpose back in the day. I did on two of my M3s. They did that for a decade or more. So 1/2 quart isn't a big deal. If all it took was a 1/2 quart to make or break you, you'd total your engines every time you took a turn. The engine is a very dynamic violent place. And yes i'm well aware of crank aeration.

As far as when to check it, best to check when warm and after the engine has been shut down. Depends how the dip stick was designed to be calibrated.

Though at the end of the day, a dangerously low oil level will be low regardless of the temp of the oil. And of course no oil will always be no oil. So check whenever.
Not sure I'm on board with half a quart over being ok.
Personally anything more than a quarter of a quart and I'd be draining off the excess.

And dedicated track cars are purpose built and shouldn't be compared to street cars. Street cars you want to last 10 years at least, track cars just need to last 10 hours on a race weekend then you can rebuild during the week.
So it's like comparing apples and poodles.

I guess if it's ok to go above and beyond the manufacturers design oil capacity for the engine, when is too much, too much.
Is 1 quart over ok, is 2...is 3...why not just double the amount of oil in the engine...that way you're sure everything is always lubricated...is there even a line in the sand anymore.
Maybe you can overfill you CT with 2 quarts and let us know what happens in 500 miles.

The reality is when you start to increase the volume of oil in the engine, this then reduces that space available for the natural pressure that builds internally when the engine is running...hence why we have PCV systems.
If that pressure is now higher than the PCV system can handle, well, it has to go somewhere, and it's gonna take the oil with it...this is when seals, all of a sudden, start to leak. The pressure and oil will find the weakest point and escape the engine.
Reply
ClubLexus Stories

Celebrating Lexus & Toyota from Around the Globe

story-0

10 Lexus Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-1

8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!

 Michael S. Palmer
story-2

10 Best Lexus Models No One Remembers

 Joe Kucinski
story-3

TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing

 Michael S. Palmer
story-4

Top 10 Lexus & Toyotas to Drive Before You Die!

 Joe Kucinski
story-5

Top 10 Lexus/Toyotas With The LEAST 5-Year Depreciation

 Joe Kucinski
story-6

Lexus LC500 Convertible Auction: A Preview of Rising Values?

 Brett Foote
story-7

GX 550 vs TX 550: Best 3-Row Luxury Lexus Family Hauler

 Michael S. Palmer
story-8

9 Best Lexus Models You Can Buy for Half Price (And 1 You Shouldn't!)

 Joe Kucinski
story-9

2026 Lexus NX Buyer's Guide: Models, Features, Prices & More!

 Brett Foote
Old May 27, 2020 | 09:14 AM
  #9  
HOMER350's Avatar
HOMER350
Racer
 
Joined: Mar 2018
Posts: 1,589
Likes: 317
From: SoCal
Default

Originally Posted by Sasnuke
Not sure I'm on board with half a quart over being ok.
Personally anything more than a quarter of a quart and I'd be draining off the excess.

And dedicated track cars are purpose built and shouldn't be compared to street cars. Street cars you want to last 10 years at least, track cars just need to last 10 hours on a race weekend then you can rebuild during the week.
So it's like comparing apples and poodles.

I guess if it's ok to go above and beyond the manufacturers design oil capacity for the engine, when is too much, too much.
Is 1 quart over ok, is 2...is 3...why not just double the amount of oil in the engine...that way you're sure everything is always lubricated...is there even a line in the sand anymore.
Maybe you can overfill you CT with 2 quarts and let us know what happens in 500 miles.

The reality is when you start to increase the volume of oil in the engine, this then reduces that space available for the natural pressure that builds internally when the engine is running...hence why we have PCV systems.
If that pressure is now higher than the PCV system can handle, well, it has to go somewhere, and it's gonna take the oil with it...this is when seals, all of a sudden, start to leak. The pressure and oil will find the weakest point and escape the engine.
I also read on the internet (so must be true) and makes sense, too much oil will cause it to be come foamy, and foamy oil doesn't provide the needed lubrication.
Air pressure being off. Air kind of mixes with the oil, becomes foamy. Something to that extent.
Reply
Old May 27, 2020 | 10:30 AM
  #10  
Sasnuke's Avatar
Sasnuke
Lexus Test Driver
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2017
Posts: 6,260
Likes: 1,752
From: Richmond Hill, Ontario, Canada
Default

Originally Posted by HOMER350
I also read on the internet (so must be true) and makes sense, too much oil will cause it to be come foamy, and foamy oil doesn't provide the needed lubrication.
Air pressure being off. Air kind of mixes with the oil, becomes foamy. Something to that extent.
Exactly...that was the "crankcase aeration" mentioned in E46CT's post.
Reply
Old May 27, 2020 | 10:46 AM
  #11  
NickCaesar's Avatar
NickCaesar
Instructor
 
Joined: Jan 2019
Posts: 853
Likes: 175
From: Ontario
Default

Originally Posted by E46CT
Half a quart isn't anything to worry about. You'd get higher levels of sloshing from just sitting in your car or going over a speed bump. I verified this back in the day by pulling the oil pans and doing some measurements because this same thing used to float around before.

In fact, some of the BMW track guys used to over fill by 1-2 quarts on purpose back in the day. I did on two of my M3s. They did that for a decade or more. So 1/2 quart isn't a big deal. If all it took was a 1/2 quart to make or break you, you'd total your engines every time you took a turn. The engine is a very dynamic violent place. And yes i'm well aware of crank aeration.

As far as when to check it, best to check when warm and after the engine has been shut down. Depends how the dip stick was designed to be calibrated.

Though at the end of the day, a dangerously low oil level will be low regardless of the temp of the oil. And of course no oil will always be no oil. So check whenever.
It was mainly my OCD kicking in. But it only took me 10-15 min to Mcgyver a pump and siphon out a half quart.
Reply
Old May 27, 2020 | 11:14 AM
  #12  
Sasnuke's Avatar
Sasnuke
Lexus Test Driver
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2017
Posts: 6,260
Likes: 1,752
From: Richmond Hill, Ontario, Canada
Default

Originally Posted by NickCaesar
It was mainly my OCD kicking in. But it only took me 10-15 min to Mcgyver a pump and siphon out a half quart.
Speaking of, I just had this arrive:
https://www.amazon.ca/OEMTOOLS-24936-Manual-Extractor-Gallons/dp/B07N7XC7DM/ref=sr_1_1?dchild=1&keywords=oemtools&qid=1590603107&sr=8-1 https://www.amazon.ca/OEMTOOLS-24936-Manual-Extractor-Gallons/dp/B07N7XC7DM/ref=sr_1_1?dchild=1&keywords=oemtools&qid=1590603107&sr=8-1

Unfortunately I just recently did the oil change on the Lex, so I'll be breaking this in on my Highlander in the next week or two.
The Lex will still require crawling under it to get the filter, but then I don't need it that high or need to get under it that far if I don't need to get to the pan.
Reply
Old May 27, 2020 | 11:46 AM
  #13  
NickCaesar's Avatar
NickCaesar
Instructor
 
Joined: Jan 2019
Posts: 853
Likes: 175
From: Ontario
Default

Originally Posted by Sasnuke
Speaking of, I just had this arrive: https://www.amazon.ca/OEMTOOLS-24936...0603107&sr=8-1

Unfortunately I just recently did the oil change on the Lex, so I'll be breaking this in on my Highlander in the next week or two.
The Lex will still require crawling under it to get the filter, but then I don't need it that high or need to get under it that far if I don't need to get to the pan.
Nice, that will come in handy. I waited until car cooled down than stuck a thin tube down the dipstick tube into the oil pan and pulled out the excess.
Reply
Old May 27, 2020 | 03:11 PM
  #14  
spindos's Avatar
spindos
Thread Starter
Driver School Candidate
 
Joined: Mar 2019
Posts: 47
Likes: 2
From: CA
Default

Thank you everyone for your input/advice.

Is it normal for my oil level to appear higher when the engine is cold? There's a pretty significant difference when I measure the oil level cold versus warm (~1 hour after driving).


Reply
Old May 27, 2020 | 05:13 PM
  #15  
HOMER350's Avatar
HOMER350
Racer
 
Joined: Mar 2018
Posts: 1,589
Likes: 317
From: SoCal
Default

Originally Posted by spindos
Thank you everyone for your input/advice.

Is it normal for my oil level to appear higher when the engine is cold? There's a pretty significant difference when I measure the oil level cold versus warm (~1 hour after driving).

yeah sorry I had it backwards before. Should be higher when cold be cause its all sitting in the pan. Right after running will be the lowest, thats why it was suggested to wait after running and check while warm. Personally I like mine at the top line when cold. About a half inch difference looks familiar. Just if it were me I'd add some, but don't take just my word for it.
Reply



All times are GMT -7. The time now is 08:54 AM.

story-0
10 Lexus Designs That Have Aged Like Fine Wine

Slideshow: Some luxury cars chase trends, but these Lexus models look better now than they did when they first rolled into showrooms.

By Verdad Gallardo | 2026-05-06 17:58:29


VIEW MORE
story-1
8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!

Slideshow: How to Get the Best Fuel Economy with a Hybrid and Plug-In Hybrid!

By Michael S. Palmer | 2026-05-05 20:54:44


VIEW MORE
story-2
10 Best Lexus Models No One Remembers

Slideshow: 10 best Lexus models no one remembers.

By Joe Kucinski | 2026-05-05 17:33:28


VIEW MORE
story-3
TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing

Slideshow: diving into 4Runner TRD Off-Road Premium's pricing, performance, fuel economy, features, and amenities!

By Michael S. Palmer | 2026-04-23 13:09:18


VIEW MORE
story-4
Top 10 Lexus & Toyotas to Drive Before You Die!

Slideshow: the 10 Lexus and Toyota vehicles you need to drive before you die.

By Joe Kucinski | 2026-04-23 10:34:24


VIEW MORE
story-5
Top 10 Lexus/Toyotas With The LEAST 5-Year Depreciation

Slideshow: Top 10 Lexus/Toyota models with the lowest 5-year depreciation rate.

By Joe Kucinski | 2026-04-08 12:19:06


VIEW MORE
story-6
Lexus LC500 Convertible Auction: A Preview of Rising Values?

The LC hasn't even disappeared from the Lexus lineup yet, and we're already seeing signs of an explosive market.

By Brett Foote | 2026-04-06 09:25:02


VIEW MORE
story-7
GX 550 vs TX 550: Best 3-Row Luxury Lexus Family Hauler

Slideshow: comparing the pricings, specs, power, fuel economy, fun-factor, and features of the GX 550 Luxury+ and TX 550h+ Luxury.

By Michael S. Palmer | 2026-03-19 13:44:11


VIEW MORE
story-8
9 Best Lexus Models You Can Buy for Half Price (And 1 You Shouldn't!)

Slideshow: 9 best Lexus models you can buy for half price and 1 you should avoid

By Joe Kucinski | 2026-03-19 12:01:07


VIEW MORE
story-9
2026 Lexus NX Buyer's Guide: Models, Features, Prices & More!

Here's everything you need to know about the latest NX.

By Brett Foote | 2026-03-19 11:56:59


VIEW MORE