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View Full Version : Red dipstick, yellow dipstick, checking oil hot or cold...


jackbombay
02-21-2013, 11:25 PM
Most of us know that with the red dipstick you are supposed to check your oil when it is hot, and with the yellow dipstick you check the oil when the engine is cold. I've always doubted there was any significant difference between the oil level of the engine while hot and while cold, so I checked it today.

I ran the van till it was all the way warmed up and checked the oil level exactly 5 miutes after shutting the engine off, and I made a small scratch on the dipstick right at the oil level.

I let the van sit for one hour outside at 18* F and checked the oil level again, and the oil level had dropped about 1/32" about .6mm (point 6 millimeter) so IMO you can check you oil cold and not think twice about it especially when we consider these vans can run a quart low and be just fine...

shortshort
02-22-2013, 12:51 AM
5 minutes may not be time for the oil to drain, an hour might not be enough time to cool, etc. I agree though, in a 9 liter sump, bfd.

autostaretx
02-22-2013, 03:07 AM
On my 2005 T1N with the 647 engine, the hot/cold difference is 1/2 quart (almost precisely).
I have a Red stick, and it reads 1/2 quart low at 45F (after an overnight park).

--dick

skill3
02-22-2013, 05:11 AM
This has never made sense to me. If the capacity is 9 quarts (for discussion point only) and you drain the oil and change filter. You add the 9 quarts as required. You then check the dipstick. Wherever the oil line is at the point on the dipstick should be the required capacity mark. So, doesn't it only make sense that you check the engine cold. If you check it hot, the oil level will be low. Of course, that would depend on how much time you allow for the engine oil to drain back. If you check it before starting the engine, then that should tell you if the oil level has dropped. Does this make sense or am I missing some quirky detail about diesel engines? I'm 64 years old and I have owned over 50 GM cars, but that has always been the way I checked my oil. I have never had a low oil engine failure.

talkinghorse43
02-22-2013, 01:06 PM
Since, with a big sump, oil level is sensitive to temperature, hot is always about the same temperature, while cold can be anything between 100F and -50F.

Aqua Puttana
02-22-2013, 01:16 PM
What TH43 said about ambient. It also applies to transmissions with the additional possiblility of unequal drain down from the transmission passages depending upon valve position, thermostatic controls, etc.

...I'm 64 years old and I have owned over 50 GM cars, but that has always been the way I checked my oil. I have never had a low oil engine failure.

My opinion... The same as with many things related to Mercedes, in their pursuit of precision they don't leave much slop even when it comes to fluid levels. Detroit iron design was OK with a 1/2 quart overfill error. Do that in your Sprinter and you get a high oil dash warning.

Knowing that the high oil level dash indication can be a problem my goal is to be within the range, not at the very top of it. I truly believe that they give us a range for a reason. Checking the level hot as is described in the operator manual is easy to do and repeatable as to accuracy. FWIW. vic

flman
02-22-2013, 02:16 PM
Why not check it ice cold after sitting overnight, then check it again later when it is hot? :2cents:

But I agree, the oil is not going to expand all that much any ways?

talkinghorse43
02-22-2013, 02:41 PM
Can be calculated here:

http://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html

I plugged in 9 qts heated from 50F to 200F and found oil expands to 9.5 qts. Same as post 3.

thinice
02-22-2013, 03:34 PM
Why not check it ice cold after sitting overnight, then check it again later when it is hot? :2cents:

But I agree, the oil is not going to expand all that much any ways?

Right about the oil, wrong about Jefferson. Many right wingers like to attribute this quote to Jefferson but there is no proof he actually said that. Maybe he said it to the over 600 slaves he owned but there is no record of it? :rolleyes:

autostaretx
02-22-2013, 03:38 PM
Why not check it ice cold after sitting overnight, then check it again later when it is hot?
..which is what i did (in post #3)... the (unreported, but assumed) later-in-day-and-hot reading showed exactly full.

As TalkingHorse points out, "ice cold" can be a very wide range (today it's 42 and rain... but i'm not in Florida, Kansas or Minnesota)

I also appreciate him for digging out the Thermal Expansion site... i'd been too busy/lazy/rushed to try to find one yesterday.
I would not have guessed that oil had more than 3x the expansion coefficient of water.

--dick (whose dipstick now can be used hot or cold (at 45F), since i know where cold(ish)-full reads)

flman
02-22-2013, 06:13 PM
Maybe he said it to the over 600 slaves he owned but there is no record of it? :rolleyes:

Well, maybe he wanted the slaves to keep working, but yeah I guess the source is unknown? Doesn't every one that comes to America think it really is a democracy? http://www.foundingfatherquotes.com/search.php?q=democracy&Submit=GO

BTW, I found a more documented quote, and if you want, go to the danger zone and you can tell me weather it is hoaky or not there.

Aqua Puttana
02-22-2013, 08:10 PM
Well, maybe he wanted the slaves to keep working, ...

I appreciate that threads can meander... in fact I think often it helps to surface Sprinter information that otherwise would go unheard, but aren't these type of comments the kinda stuff which Sikwan created the danger zone for? :idunno:

Carry on. vic

flman
02-22-2013, 09:31 PM
I appreciate that threads can meander... in fact I think often it helps to surface Sprinter information that otherwise would go unheard, but aren't these type of comments the kinda stuff which Sikwan created the danger zone for? :idunno:

Carry on. vic

Right, did I not to tell them to go to the DZ? :popcorn:

Aqua Puttana
02-22-2013, 10:14 PM
Right, did I not to tell them to go to the DZ? :popcorn:
The first comment caught my attention to the point where I really didn't read though the entire post. Good that you suggested going to the Danger Zone. :thumbup:

Thanks. vic

thinice
02-23-2013, 01:58 AM
I agree that quote belongs in the Danger Zone but since it appeared so many times in this part of the forum, in a signature, it seemed like fair game for a "Facts Check". Point made, I'm done.
Lets all chill out and get back to talking about our dipsticks.:snore: