Check oil when COLD..any owners manual say this?

[ammolab]

I can tell from several posts that many vehicle owners use a "check oil when cold, overnight, etc" technique, but I have never seen this listed in a vehicle owners manual that I can remember. I got my first new car in 1964 and many more since then. I always read the manual and it seems they always say "shut down at operating temp and wait a few minutes, then check oil level".

Seems like oil level at operating temp is the level that is important in an engine and dipsticks did exist when oil was checked at fuel stops by the pump jockey (hot, a few minutes after shutoff).

Do any modern manuals say, "check when cold"? Just wondered.

 

[strongt]

Here's what my Jeep's owners manual states:

"The best time to check the engine oil level is about 5
minutes after a fully warmed engine is shut off or before
starting the engine after it has sat overnight."

It funny that it also states that no matter what, do not go past 6,000 Miles on a oil change:

Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
² Day or night temperatures are below 32°F (0°C)
² Stop and go driving
² Extensive engine idling
² Driving in dusty conditions
² Short trips of less than 10 miles (16.2 km)
² More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
² Trailer towing
² Taxi, Police, or delivery service (Commercial Service)
² Off road or desert operation
² If equipped for and operating with E-85 (ethanol) fuel
If ANY of these apply to you, then change your engine oil
every 3,000 miles (5 000 km) or 3 months, whichever
comes first, and follow the maintenance recommendations
in “Maintenance Schedule B.”
If none of these apply to you, then change your engine oil
every 6,000 miles (10 000 km) or 6 months, whichever
comes first.
NOTE: Under no circumstances should oil change intervals
exceed 6,000 miles (10 000 km) or 6 months
whichever comes first.

 

[Chris142]

my f250 says hot

 

[dparm]

No, my Audis explicitly said NOT to do that. Both had to be measured after the car reached normal operating temperature, but three minutes AFTER it was turned off.

My 2005 S4 had a dipstick so this was easy.

My 2011 S4 didn't have one and relies on a sensor. The MMI display actually says oil level cannot be shown until the car has been driven for several minutes.

 

[Lead Shoes]

Originally Posted By: dparm
No, my Audis explicitly said NOT to do that. Both had to be measured after the car reached normal operating temperature, but three minutes AFTER it was turned off.

My 2005 S4 had a dipstick so this was easy.

My 2011 S4 didn't have one and relies on a sensor. The MMI display actually says oil level cannot be shown until the car has been driven for several minutes.


I would go nuts relying on a sensor to tell me the oil level... I would have to add a dipstick..

I have always checked mine cold or hot after a 5 minute rest, either way I have never had the reading vary by a noticeable amount in my own testing.

 

[KB2008X]

Either way is fine, unless the manual tells you otherwise.

I always check it before it's been run because you can just pull it out once and check it. No wiping and sticking it again. Just pull the stick out and check it. If the oil is hot it can start to run down the stick before you can get it all the way out. Which can mean sticking it yet again.

Keith

 

[Jim Allen]

Best hot because the oil expands with heat. One Ford document I have says oil expands at a rate of 1 percent per 25F of oil temperature. So if you fill to the top line when cold, say at 60F, you are overfull at 200F. How much more the hot oil level will climb in the crankcase will have many variables according to surface are, etc. And obviously you account for this while checking the level, but this 1%/25F is a useful number to have in the back of one's mind.

 

[Eddie]

2007 Mazda states 5 minutes or more after shutdown. My Subaru Forester has a normal add & full mark plus and maximum hot mark above the normal full line.

 

[TFB1]

Originally Posted By: Jim Allen
Best hot because the oil expands with heat.


I suppose on a large system of at least eight quarts, it'd be better to check hot but on a system of six quarts or less, it isn't going to make a noticeable difference... Does make a difference in a automatic transmission, 12qts will expand close to a pint from cold to full operating temp...

For checking, my manual for the '98 Grand Marquis says check every time the vehicle is refueled... Also states allow a few minutes for oil drainback into the pan and protect your self from heat, so Ford is no doubt recommending hot...

Now devils advocate... I mostly buy gas at a station that's maybe 1/3 mi from home, not much chance the oil is even warm, think I'll keep checking my mine when cold... Reminds me I probably should do so, been a month since I changed oil, hood hasn't been open since...

 

[N7Quarian]

My car says to check it when hot, but I check it both ways.

 

[tommygunn]

I don't have a manual LOL and never had a car that stated how and when to check it....but typically check in when refueling....though my process is thisop good, get out, pump gas, wash all windows with squigee if provided, prop hood, pull out quick, wipe clean, reinsert, check....if it's low, I'll check it again the next morning and add if it's at or below add line

 

[Malo83]

I always check mine in the morning, seems to give the best reading on the stick after all the oil has drained down overnight

 

[LeakySeals]

I see "at every gas fill" in manuals from different manufacturers. Would think thats not very reliable.

 

[dparm]

Originally Posted By: LeakySeals
I see "at every gas fill" in manuals from different manufacturers. Would think thats not very reliable.


Short of driving 100 yards to get gas, I would think this is probably fine.

 

[ltslimjim]

At the gas station, AFTER filling and closing off the gas tank. Then, just pop the hood and check the level.

 

[KCJeep]

My manual says, check cold after having sat overnight OR check hot after letting sit for 5 minutes after shutting off.

 

[Garak]

Originally Posted By: dparm
Short of driving 100 yards to get gas, I would think this is probably fine.


There is another issue, however. Gas station lots aren't always perfectly level. Even a slight off level made a huge difference in the Audi, making it look half a litre short or half a litre over, depending upon the direction of the grade.

Personally, I tend to check it first thing in the morning in the garage (the floor is level). Or I wait a few minutes, and that works, too.

 

[Mr Nice]

Originally Posted By: Malo83
I always check mine in the morning, seems to give the best reading on the stick after all the oil has drained down overnight

Yep. + 1000000%

 

[Ken2]

Not that big a deal. Anywhere in the upper half of the zone on the dipstick is OK for me.

 

[GatorJoe]

I check it cold, before driving. Top of the recommended range on dipstick is what I'm looking for. Top it off. Check it about every weekend or two.