micro bubbles in my oil ???

02 green tb

Original poster
Member
Dec 4, 2011
30
San Antonio, TX
So yesterday I went to change my oil. I was parked on an incline so I started the truck and truned it around so that it was facing ownhill. The truck was only on for about 2 minutes max so that way the engine didn't have time to heat up making the oil change easier for me. So I got under the truck and took off the bolt. While it was draining when it got towards the end I noticed small air bubbles in the oil. I know air bubbles means water got in somehow. What my question is, before I go further, do you think the air bubbles were caused by starting the truck and draining the oil right after, or is it really a serious problem? I checked the oil after changing it and going on a 35 mile trip, while the engine was hot and didn'tnotice any bubbles in the new oil. I also don't see where the coolant level has dropped either. Please leave your comments abouth this issue. 2002 with 160,000 miles.:undecided:
 

ieatglue

Member
Nov 20, 2011
152
Any oil additives?
 

navigator

Member
Dec 3, 2011
504
I have heard there can be a little moisture in the engine due to condensation, heating/cooling that basically cooks off when running.
I expect you didn't run it enough to cook it off moisture, it just mixed it in the oil.

If I wasn't loosing coolant or "gaining" oil or getting any milkshake look and things were running ok, I don't think I would worry about it.

I usually let my cars warm up so that the oil is warmer and I get more of the old oil out. It might not matter a lick but it kind of makes sense to me.
 

RayVoy

Member
Nov 20, 2011
939
I doubt if your seeing water bubbles in the oil.

When water mixes with oil, it becomes gray to milky in colour; if your oil is still golden, you do not have water tapped in the oil.

I suspect you have tiny air bubbles (aeration).

Pumping the oil around the engine, causes it to pick up small amounts of air, as the oil "rests" in the pan, the air dissipates (as in an opened pop bottle), the longer the oil sits in the pan, the more air escapes. This may be one of the reasons we have a large pan on the 4.2 engine.

Some air is normal, a lot of air is not. A lot of air may be an indicator of an overfill where the oil is whipped by the crank and piston caps.
 
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07Blazerman

Member
Dec 4, 2011
102
:iagree:
RayVoy said:
I doubt if your seeing water bubbles in the oil.

When water mixes with oil, it becomes gray to milky in colour; if your oil is still golden, you do not have water tapped in the oil.

I suspect you have tiny air bubbles (aeration).

Pumping the oil around the engine, causes it to pick up small amounts of air, as the oil "rests" in the pan, the air dissipates (as in an opened pop bottle), the longer the oil sits in the pan, the more air escapes. This may be one of the reasons we have a large pan on the 4.2 engine.

Some air is normal, a lot of air is not. A lot of air may be an indicator of an overfill where the oil is whipped by the crank and piston caps.
 

02 green tb

Original poster
Member
Dec 4, 2011
30
San Antonio, TX
Thanks for the repluies guys. I have checked my oil since the change and have not noticed any bubbles at all. Someone told me that by turning on the truck and shutting it off in such a brief time before changing the oil may have lead to the oil foaming up and causing the air bubbles. I think this is just a false alarm for now. I will keep an eye on it. BTW, there are no additives in the oil.!
 

zaid3ssaf

Member
Jan 1, 2020
154
Midwest
Thanks for the repluies guys. I have checked my oil since the change and have not noticed any bubbles at all. Someone told me that by turning on the truck and shutting it off in such a brief time before changing the oil may have lead to the oil foaming up and causing the air bubbles. I think this is just a false alarm for now. I will keep an eye on it. BTW, there are no additives in the oil.!
11 years later. Same exact thing happened to me; I started the cold car to put it in the driveway to change the oil. The oil came out with bubbles towards the end. I let the oil settle in the plastic pan overnight, all the bubbles burst and there was no water at the bottom of the pan (water is heavier). So, I got my relief. 2002 with 256k miles.
 

Mooseman

Moderator
Dec 4, 2011
25,660
Ottawa, ON
I think it's just aeration. Colder oil is thicker and would retain air bubbles longer as they would take longer to rise to the surface. If you would run it until hot, there would be less.
 

mrrsm

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Oct 22, 2015
7,982
Tampa Bay Area
These Engines Drive Oil by means of a STRONG SUCTION VACUUM created in the Slip-Gearing and Rounded Lobes of the Gerotor Oil Pump Cogs that WILL DRAW IN AMBIENT AIR if the Oil Pick Up Tube "O" Ring or Seal is compromised, poorly installed, ripped or just plain Flattened Out.

The Top of the Oil Pick Up Tube where it fastens to the Intake Manifold Port of the Gerotor Oil Pump.allows the "O" Ring inside there to be Well ABOVE the "Oil Level Water Line" where it collects below that position down inside the Bottom of the Crank-Case Oil Pan and thus, it is constantly exposed to AIR available around that Flange Connection Point.
 
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