Why run engine before checking oil?

[Larry Fine]

Why are we told to warm up, then stop the engine and wait ten minutes before checking the oil?

What happens after an hour of stopping the engine that makes the reading inaccurate?

 

[jfheath]

I think the issue is that the bike may have been moved around or put on its side stand. The STs have hiding places, where oil can disappear. Put it on its side stand and when you put it upright again, the oil will still not show in the sight glass.

The instruction to put the bike upright and run the engine gets the oil thin and moving freely round the engine. The 10 minute wait is to give the oil chance to return back to the oil pan.

I always view mine on a cold engine. But if I know I am going to check the oil properly, I ride the bike into the garage, get off it with the engine running and keep the bike upright, and put it straight onto the centre stand, then turn off the engine. I don't care how long it sits like that before I check the level.

Warm oil takes up more space than cold so the level will be a tad higher.

 

[Erdoc48]

I normally check mine when it’s cold as well (on the center stand, and as long as the level is between the 2 lines and nothing on the floor, I’m good to go). The usual time checking it warm is after an oil change, then run it to fill the oil filter and other areas- I let the bike sit for a while when changing the oil as it seems to take a while for it to rise up in the sight glass. Many prefer the sight glass- I’d prefer a dipstick like in a car.

 

[Al Gully]

I think it could be a disclaimer to say, hey did you tighten down the fill cap, did you not forget to put the seal washer on the drain plug, did you forget torque down the oil filter. Drip Drip Drip
We all know there are so many disruptions in life and a small error could create havoc.
10 minutes is plenty of time for these issues to crop up and say hey, I made an error, lets fix it.

 

[Upt' North]

I don't, and I think it's why many report excess oil usage......check it cold after leaving it on the centre stand. Preferably overnight. I know the VStrom I've just acquired says something like run for three minutes and then leave for three minutes. Then check, why? All the oil will not have returned that quickly and especially after only running for three minutes.
It used to be common practice on European Autoroutes to have your petrol pumped for you by a helpful assistant. They would inevitably be friendly, wipe your windscreen, ask to check your oil, guess what, you needed a litre or your engine was about to implode. The amount of smoking cars leaving the services was a sight to behold. I presume 500 miles later it all happened again.
Wait, Larry.......is this just a cunning plan to start an oil thread.
Upt'North.

Why are we told to warm up, then stop the engine and wait ten minutes before checking the oil?

What happens after an hour of stopping the engine that makes the reading inaccurate?

 

[Bmacleod]

I always figured it is to prevent a high reading caused by a leaky oil filter anti drainback valve that allowed the oil that should stay in the filter, to slowly drainback into the engine. I thought it was to "refill" the filter, just in case this has occured. I could be wrong... just a guess. Some filters use cheap rubber for the anti drainback valves and are prone to leaking. The problem is more noticeable with a sideways mounted filter.

 

[Kevcules]

The manual says to wait 2-3 minutes after shutting off the engine to check the level. I'm assuming the level is checked then because that dictates the oil level when the engine is running, which is the end goal.

 

[The Dan]

LOL I never check my oil...I change it every 5k and no leak on the ground so no reason to worry....It's a Honda.

 

[Chris09]

can't be, but now that you mention oil, finally did my first ST oil change - marching band starts [in head], air fills with batons, oil crowd gathers along the route [it's great being me].
made another near bad mistake, used a spring activated tool and didn't realize the tension I could feel was due to squeezing the side of it a bit between the filter and casting; fortunately no damage. Never seen anyone mention it probably goes without saying but I'd say as many as two to three seconds before oil light went out, no audible difference but I thought I'd rather run the engine just before changing the oil filter to hang up as much oil in the galleries and so on while the pump primes the filter.

 

[SMSW]

The manual says to wait 2-3 minutes after shutting off the engine to check the level. I'm assuming the level is checked then because that dictates the oil level when the engine is running, which is the end goal.

Yup, and I think I remember that the warm up was only a few minutes, not 10. Regardless, a few min is not enough to thoroughly warm up the oil and engine.

My guess here - worth as much as all the other informed guesses - is that Honda wants oil distributed throughout the engine, then allowed to drain excess off to the sump. Checking after a short drain down (not overnight) ensures that there will be sufficient oil in the oil pan to lube the engine. I admit this makes not a lot of sense to me, since I used to ride up my driveway, jockey the bike into the garage, and often check the sight glass in the AM before starting while in the garage. It was always the same as had I checked it the afternoon before, +/- an indistinguishable hair.

 

[ad.hom]

Warmed up oil flows around easier. Some folks still check oil with their bike on the side stand instead of it being level.

Mother Honda, being a corporation that didn't want suing, had to do it as an idiots guide type procedure - that probably sums it up.

Leave it on the stand, give sufficient time for the oil to drip, make sure it's between the high & low marks, and job jobbed. Doesn't matter really if that time is 2-3mins, or 2-3 decades, the oil level will be the same (unless you have a leak). Note, if you're leaving it 2-3 decades between changing oil, you're braver than I, and I would suggest you only check the level of the new stuff you're putting in, rather than the old stuff.

 

[Bmacleod]

so, looking further into this, it seems most still maintain checking when cold, but I found some suggestions that synthetic oils have a wider degree of expansion and contraction and even saw one statement that some manufacturers have recalibrated their dipsticks to reflect a warm engine. Seems a little extreme to me, especially for a bike with a capacity of 1 gallon. Cars may be different, but I still find it hard to believe there can be that much difference, but, who knows. I still check mine cold, always have and always will

 

[Andrew Shadow]

Why are we told to warm up, then stop the engine and wait ten minutes before checking the oil?

To make sure that the new oil filter is filled and saturated with oil, and to allow the oil to drain back to the sump before you check the level. Not doing so would result in the oil level reading being low by the amount the filter consumes and what it still up in the engine. Adding more oil based on that reading would result in it being overfilled.

What happens after an hour of stopping the engine that makes the reading inaccurate?

My guess- nothing. A time period had to be specified. It had to be long enough to allow enough oil to drain back to the sump to get an acceptable oil level indication. Honda determined that ten minutes was enough time to allow enough oil to drain back down for the oil level reading to be accurate enough to not be an issue. Specifying any longer would not change the accuracy enough to make a significant enough difference in the oil level to make any difference to the engine, so would not achieve any better result as far as providing sufficient lubrication.

 

[Larry Fine]

To make sure that the new oil filter is filled and saturated with oil, and to allow the oil to drain back to the sump before you check the level. Not doing so would result in the oil level reading being low by the amount the filter consumes and what it still up in the engine. Adding more oil based on that reading would result in it being overfilled.

I'm talking about every oil-level check, not just after an oil-and-filter change.

 

[rjs987]

It's not just Honda. Every brand has a similar procedure stated for checking the oil. Part of it is to get the oil warmed up so it flows easier. Thus the 10 minutes to run the engine to warm up the oil. Another part is to wait a few minutes. Warm oil foams, some more than others. So checking too soon and you'll get the level of foamed up oil resulting in a level too high. But don't wait too long since another part of proper oil level is that there needs to be a prescribed amount of oil in the pan ALONG WITH some oil coating the parts. So 2-3 or 5 minutes is plenty to wait for the foaming to go down and also for the oil to run back into the pan leaving some oil coating engine parts to show a correct reading. Waiting too long and even more oil will run off all the parts in the engine leading to a slightly high reading. And then there is the issue of making sure the oil has properly filled the filter after an oil and filter change. All my Honda's had a sight glass except my Gold Wing. My Burgman had a sight glass also but my AK 550 has a dip stick. The dip stick is easier for me to use. I do find that if I check the oil after letting the bike sit overnight or longer that the level is a little higher than if I followed the procedure in the manual. Not usually TOO high if I initially filled to the middle of the range. But just a little closer to the high mark.

 

[Gandolkf]

I saw a video of the new Goldwing, he checked it when cold, sat overnight....no oil on dipstick.
per Honda instructions warm up, turn off let set. Oil level good.
he also made a big deal of on stand, and hold bike upright.

also theres 3 drain plugs on new Wing.

 

[Bmacleod]

I saw a video of the new Goldwing, he checked it when cold, sat overnight....no oil on dipstick.
per Honda instructions warm up, turn off let set. Oil level good.
he also made a big deal of on stand, and hold bike upright.

also theres 3 drain plugs on new Wing.

So in the video, the guy says that Honda's instructions say "don't worry that no oil is showing on the dipstick, just start it up and let it run for a while and then check it, the oil should be there then"???
That makes no sense.
What happens if there actually is no oil in the engine???

 

[Andrew Shadow]

I'm talking about every oil-level check, not just after an oil-and-filter change.

Same answer, take out the part about saturating a new filter.

 

[Al st1100]

does anyone here think that if I ran my honda just below the low line all the time that I could do damage to the engine?

 

[Al st1100]

So in the video, the guy says that Honda's instructions say "don't worry that no oil is showing on the dipstick, just start it up and let it run for a while and then check it, the oil should be there then"???
That makes no sense.
What happens if there actually is no oil in the engine???

it sound to me that there is an internal reservoir that feeds the oil pump. if it sits too long the oil seeps down thru the oil pump kind of like the old Porsche dry sump system.