Checking your oil... cold.

randy1149

New member
It is with much trepidation that I am post this. It has created many arguments, personal attacks, threats, warnings and banning by the powers to be on other forums. If you don't like it or don't want to do it, then by all means don't. I welcome any and all responses including those that have technical and violations of laws of physics why this won't work, be as technically specific as you can. Honda's method in the owner manual is NOT a reason why it won't work.

This is a very simple procedure, but before I post it, my experience it is better accepted as an additional way to check your oil along with the one in the Owners Manual (OM). There's a few things like Coefficient of Expansion (CE) that has to be explained for a complete physics understanding of what’s happening and when it should be used and when not.

I want to make sure it us understood this is a simple quick and easy way to check your oil and give you a go/no go ballpark reading on your stick for a daily ride. It’s NOT intended to be used when your changing your oil and filters. Then you should use the procedure in the owners manual (OM).

First let’s look at the OM check oil procedure and why Honda recommends it. Honda says:
If engine is cold start the bike and run it 3-5 minutes.
Stop the engine and wait 2-3 minutes.
Put the bike straight up.
Remove and wipe dip stick.
Insert stick into engine but don’t screw it in and check oil level.
Screw stick back in.
Now what I’m interested in are steps 1, 2. But before I do, we must understand Coefficient of Expansion of Petroleum (CEP) … WTF is CEP. Petroleum (oil) expands or contracts as the temperature is heated and cooled. This expansion will have an affect on where the oil level appears on the stick. So to create a relatively CONSISTENT temperature range Honda tell us to start the bike and let it get warm for 3-5 minutes. This range is roughly between 180F to 220F (when the fan kicks in). I have to admit it’s not an exact recommendation but better than not having a clue the temp of the oil. So step 1 is to heat the oil up into a consistent heat range for the CEP. BTW the CEP of petroleum is around 6% for every 10 Degrees F. You can look that up here Coefficinet of Expansion. Ex; I checked my oil at 24F and the oil was between the upper index and top of the blade.

Step 2 is to let the oil drain down into the sump again to create a consistent way to check the same way for all owners. With 2-3 minutes you’ll still have some oil up top again for consistency. All the rest of the steps 3-6 are pretty much self explanatory and does not affect this easy way to check your oil.

It’s goes to say the OM procedures are time consuming and really not necessary if you just want to make sure that your oil is good to go for your riding.

The cold oil check. We’re going to check our oil with a cold engine without doing steps 1 & 2 in the OM, no heating up. So here we go. First it’s paramount we insure the oil is full by using the OM procedure just one time before we can do the cold checks with certainty. So do the OM procedure and top off the oil if necessary. Once your sure the engine is full, from then on you can cold check without starting the bike. The next day or after the bike is completely cold just take the dip stick out, wipe it clean, put it back in (don’t screw in), pull the bike up straight and vertical and hold it for a few seconds to let the oil settle in the middle of the sump. Then put the bike back on stand and read the level on the dip stick. Make a mental note or write the level on the stick. THIS IS YOUR FULL MARK FOR ALL YOUR FUTURE OIL CHECKS WITH A COLD ENGINE. For hence forth if you want to check your oil, just check the oil level cold with the dip stick and vertical the bike to get the reading. Your doing the owners manual procedure without the starting of the engine steps. You can check your oil in less than a minute.

There is a caveat. Remember the CEP with 6% expansion and contraction.
If there is large temperature difference between your checking you’ll have to take the CEP 6% expansions contraction into account

So in conclusion, The only time I use the OM procedure is when I change the oil & filter. I’ve been using and posting this cold start for 20 years with replies that some people believe there is some magic occurs to the oil if you don’t follow the OM and the oil level can not be trusted. If you have those same concerns then don’t do it.

A related issue to cold engine oil checking, Hardly Davidson has a digital dip stick that allow cold check with the bike on the side stand if your willing to pay $150.… HD dip stick.
 

Merlin III

New member
That all sounds reasonable to me. I did something similar with my prior BMW. I wish i could read the old thread. :)
 

randy1149

New member
All motorcycles I've owned required the heat up and let drain down procedure, I can see your BMW wouldn't be any different. The soul reason behind heating up the bike and that is to establish a "consistent" environment so everybody checks their oil the same. There is no other reason beyond creating a consistent environment. The reason for that is due to the Coefficient of Expansion I described. The oil at 20F degrees will be at a different mark on the stick then at 90F degrees. And you have to take that into account if you want to a cold oil check. My experience is about 1/4" up / down on the stick with large temp difference. Also in these factory recommendation is let the oil drain 2 - 3 minutes. That's to get most of the oil down into the crank... you can't get an accurate reading if a lot of the oil is till up in the head. At the end of the day I ONLY use the cold check as a go no go check before I take a ride, not when changing the oil and filters.
 
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