hot or cold when checking

[mjoekingz28]

My manual says on level ground and wait a few minutes, so I assume it is saying a few minutes after turning the engine off. That leads to getting a false reading when cold, but when cold is the only reading I can get.

 

[psudaytona]

We talking about engine oil level? For an engine you need the engine off to let the oil drain back down into the pan and give you the real level. It will look low incorrectly if you check while running. The "FULL" level for dipsticks in engines are set based on engine off conditions. At least all I have dealt with.

A transmission usually has to be running in PARK or NEUTRAL. Also, it needs to be at operating temperature usually after being run through all gears. Otherwise a transmission will look incorrectly overfilled if checked when the engine is off.

 

[Eddie]

Mazda states wait 5 + minutes after shuting down a hot engine to check oil level. I've check both ways and found ~1/8 quart difference. My Subaru would vary about 1/4 quart from full hot to overnight cold. Subarus; reason was that hot oil expands. Subaru had two Full marks, one for max hot and one for cold/cool etc. I guess it depends on the oil pan design so I just follow my owners manual which I consider " A Friend"

 

[williar]

I'd go with what your owners manual says. My car's manual says
something similar, and I find that the engine oil level reads lower just after I shut down & higher after sitting overnight. Take
the oil level 5 minutes after shutdown and it reads correct.

 

[bdcardinal]

when im bored at work i read the workshop manual for the Ford GT (supercar). it says to run the motor till warm, and shut off and check warm within 5 minutes. if you wait longer, run it again. thats a dry sump though, with a fairly small sump (9 quarts).

 

[mechtech2]

The only consistent way is to check it on level ground after it has been sitting all night. Then you know that you know.

Hot/cold will make a difference, for sure. How long after turning it off makes a difference. Variances in the lie of the ground will alter the reading.

 

[Eddie]

I wonder if the gravitational pull of the full moon will effect my readings? Boy, can a simple task turn into a project when it comes to our vehicles. Ed

 

[ThirdeYe]

I always check it when it's fully cold and has sat for more than a couple hours, so I know that it's consistent.

 

[glennc]

All our Infinitis, two G20s and one I30, have been very hard to get a good reading on when recently run. So I wait overnight. Usually it goes up a bit and I just take that into account. It does seem like the most consistent way to do it.

 

[Cutehumor]

I check when cold, first thing in the morning. always get an accurate reading that way.

 

[glennc]

Why does the oil always look much darker when cold than when recently run?

 

[njcruiser]

thicker oil would look darker i would think. more in one area on the dipstick and thicker than if it were thinned out from being at temp..........