Author Topic: Bubbles in oil right after engine turned off (Read 2091 times)

bonne · « **on:** February 22, 2021, 12:22:12 »

Is it common to have small bubbles floating on top of the engine oil right after engine has been turned off?

The second I turn off the engine, the engine oil starts to rise and small bubbles are around there on the surface. After one minute they are gone.

bonne · « **Reply #1 on:** February 22, 2021, 12:53:15 »

right after 130 km/h on the motorway

bonne · « **Reply #2 on:** February 22, 2021, 14:19:53 »

And now after returning home and letting it sit for 5 min.

I have to say that I originally filled out 2-3 mm over the max and drove a few km. and I then decided to loosen the oil filter and drain some oil.

Brockett · « **Reply #3 on:** February 22, 2021, 17:43:06 »

I suspect you had too much oil in the engine.

bonne · « **Reply #4 on:** February 22, 2021, 18:48:27 »

I have no problems in changing the oil once again... if it is a problem. But as I start to understand from googeling, it is normal to have bubbles just after shutting off the engine. Or am I wrong? Do you have the same "issue" after 130km/t on the motorway? Shutting of the engine and then watching the oil level rise in the glas... after a few minutes, bubbles are gone.

Joe Rocket · « **Reply #5 on:** February 22, 2021, 18:59:44 »

Your oil appears to be new. Is it the right grade for your location/use?

I personally don't check the oil window the moment I turn the bike off. Perhaps mine has some bubbles..........

kwackboy · « **Reply #6 on:** February 22, 2021, 19:07:40 »

You've nothing to worry about ...

Ride it and enjoy ..

bonne · « **Reply #7 on:** February 22, 2021, 19:11:13 »

I also normally don't check the oil right after riding on the motorway... only because it is my first MC oil change.

I am using Castrol SAE 10w/40 JASO MA-2 (T903:2016); API SN.

The manual indicates that I should use "Suzuki Performance 4 motor oil", or "if I can't find that" then 10w/40 SG/SH/SJ/SL/SM/SN, JASO MA/MA2. So I guess the engine oil is correct even though it doesn't state "Suzuki" on it?

kwackboy · « **Reply #8 on:** February 22, 2021, 19:20:20 »

The oil you have chosen will do just fine .

Joe Rocket · « **Reply #9 on:** February 22, 2021, 19:27:36 »

Quite right kwackboy, I was only asking in case bonne was using non motorcycle oil. All seems fine.

Brockett · « **Reply #10 on:** February 22, 2021, 19:33:47 »

If it was overfilled the oil may have absorbed air due to high pressures under the pistons. When the engine stops the air rises to the surface and then disperses.

Mr Nick · « **Reply #11 on:** February 22, 2021, 19:46:24 »

Am I correct in remembering you are going to be carrying out all the future servicing of this bike yourself? Whilst not wishing to seem unkind, are you sure your technical knowledge is up to the task? There's far more than a basic oil change involved and even this seems to be something you are quite unsure of.

bonne · « **Reply #12 on:** February 22, 2021, 19:50:42 »

You are correct. I want to do the basic stuff myself, but leave the more complicated parts to a professional.

But doing oil change is something that I should be able to do... and except for overfilling slightly this time, I think I am able to do so. I have done so on all my cars, but this is the first MC... and I have never seen bubbles in a car as there are no eye sight.

Regards, Lars.

bonne · « **Reply #13 on:** February 22, 2021, 19:55:02 »

Hi Brockett - oil is exactly at the max now. The bubbles continues to be there right after engine is off, and then it settles "calmly". If air should be absorbed, and the vaporize, I image you would not see it again the next time you turn off the engine?

But as others say, it seems correct, or you do not agree?

bonne · « **Reply #14 on:** February 22, 2021, 19:56:47 »

But please... some of you... try to do the same - after a ride on the freeway, turn off the engine and look if the oil bubbles (-:

Brockett · « **Reply #15 on:** February 23, 2021, 09:42:18 »

From your photograph I would think that whatever is causing the bubbles is a minor issue and may not be a problem, but you are right to check it out and keep an eye on it in case it gets worse . Bubbles are caused by air / gas in a fluid. The air rises to the top and is trapped by the surface tension of the fluid. The air gathers in pockets (bubbles) and eventually the pressure of the air pocket overcomes the surface tension of the fluid, the air is released and the bubble disappears. Somehow, air is being absorbed into the oil. Air trapped in the filter? and again when you opened it slightly to remove some oil. A few more test runs should rule that out.
You said the oil was filled over the top mark and then then you drained some out via the filter. I may have misunderstood.
I never fill my SV with oil right up to the maximum level so as to avoid over pressure in the engine case. Over pressure in the engine case can cause the oil to froth and can damage seals. My friend did exaclty that on a Yamaha cruiser engine when he over filled although that was by a litre or so. This casued the oil to evacuate through a breather pipe as foam. This may not be the case for you. Could it be condensation as cold air is drawn in via the breather? Some members, on this forum, in the past have had the sight glass obscured by this problem. It seems to only happen in the winter and may be related to cold damp air being drawn into the engine as it cools down. You are quite right to ask people to check their bikes after a ride. I can honestly say I have never checked mine after a ride. So what you are seeing could be normal.

Have you always checked your bike's sight glass after a ride or is this something you have just noticed?

bonne · « **Reply #16 on:** February 23, 2021, 10:09:21 »

Hi - first of all, thanks for all replies.

I had an authorised dealer to do the oil change on my old bike, and I always trusted it to have been done correctly, so I never checked. As this is the first MC oil change I do by myself, I am watching out for all possible issues and asking when I am in any doubt.

I was thinking that it is not good to have bubbles in the oil, so I was prepared to do a second oil and filter change. Good that I didn't do it, because I would end up with the same "issue". I hear from others that bubbles in oil is normal after a ride - and the harder the ride, the more bubbles. The oil will be splashed around gearbox and stuff, and it is impossible not to get aired. After 3-5 minutes of restling, the bubbles should settle, and then you can check the oil for looking weird.

Try it yourself on the next ride.

Yes, the oil was overfilled slightly. But just slightly. 2-3 mm over the max setting. The engine runs perfect, starts perfect, makes no noise or white smoke. Temperature is normal. I expect nothing to be wrong. I was told to check the overflow hose for the airfilter for any oil. Where do I find that on the 1050?

Also curious to see if the spark plugs are wet, but... I do not think so. I am not planning to check that right away.

I could smell some engine oil after the oil change, but I imagine that is it from excess oil outside the engine.

Rixington43 · « **Reply #17 on:** February 23, 2021, 10:18:38 »

As you say, given the turmoil going on inside a bike gearbox and crank case, I'd be amazed if the oil didn't get slightly aerated, especially after a decent length ride where the oil will also be hottest and therefore thinnest. You don't have any discolouration or clouding of the oil which you would expect if there was any significant water ingress. I've always checked my oil before a long ride but can't say I've ever checked it when I get back so I don't know if the same happens to everbody.
If oil was getting to your plugs then I'd expect issues with starting or running a bit rough/smokey just after starting.
Always worth checking out everything you see as a bit odd and I'll certainly look at mine next time I'm actually allowed to ride it far enough to get the oil hot. I'd lean towards nothing to worry about though, you've used the correct oil and are now at an appropriate fill level so just keep an eye out for leaks or cloudy oil.

Mr Nick · « **Reply #18 on:** February 23, 2021, 11:17:22 »

Oil has specific additives ant-foam additives, although they are more about preventing the foam staying for any length of time as you can't stop the creation in the first place since it's due to mechanical agitation. You stir any liquid vigorously in air and bubbles will form. The aim is to get them to stay small and burst quickly so they don't affect the oil feed, which is from the bottom of the oil in your wet sump engine anyway, not the top where the bubbles are. If there were too many bubbles getting into the feed, then the oil pressure light would come on.

The sight glass is a source of more concerns than you'd believe: if it wasn't there then the paranoia about bubbles and milky oil wouldn't exist. People are happy for their car to go for weeks, or even months, without a glance at the oil, but have to check that little window into the mysterious every chance they get.

Rixington43 · « **Reply #19 on:** February 23, 2021, 11:22:15 »

Certainly provides enough rope to hang yourself and you're dead right on the car comparison.
Check levels before any significantly long journey where I'll be away from an effortless top up. Inspect the oil when I drain it at the end of the year.