Bubbles on dipstick

[KMG]

Hello, sorry if this is a stupid question

- I have noticed for the past several months, that when i run the truck and immediately shut it off and check the oil there are tiny bubbles noticeable that will pop or dissipate as i move the oil on the dipstick. there are none if the engine is cold or sits for 5-10 minutes. it only is noticeable when its just been driven and checked.

the coolant reservoir level has not changed and the oil color appears normal for synthetic.

Also the level is at the top mark but not significantly higher as that seems to be the most common culprit but not in this case.

Is this normal? Anything else I should check as a possible problem?

Thanks!

 

[ARunner]

Doesn't really sound like an issue to me. You're likely picking it up from oil that has just been dropped back in the pan post circulation. If it isn't milky looking, I don't think there is anything to worry about.

 

[TechWrench]

What you describe sounds a lot like cavitation bubbles caused by the oil level being too high. I know you said you checked the level, but just to be sure, are you using the correct set of level marks for the oil temp? The upper set is for when oil temp is at normal operating temp. The lower set of marks is for when oil temp is cold. Again, just making sure it isn't a level issue.

 

[ARunner]

The upper set is for when oil temp is at normal operating temp. The lower set of marks is for when oil temp is cold. Again, just making sure it isn't a level issue.

That is true for checking transmission fluid levels. Never found hot vs cold makes a difference on the engine oil dipstick.

 

[TechWrench]

That is true for checking transmission fluid levels. Never found hot vs cold makes a difference on the engine oil dipstick.

You are right, I had a brain fart and gave info about the trans dipstick instead of the engine. Do you have the V6 or V8 engine?

 

[KMG]

It's a 2006 v6 limited with 84k miles. I just got it a couple months ago!

the dipstick is the worst ive seen in regards to a clear level, it smears all over everytime i check. but the majority of the oil is just below the top of the high dot.

I changed it myself and put 5 1/3 quarts in after draining. so i don't think there is too much oil, and if there is would 1/3 a quart extra make it bubble?

 

[TechWrench]

It's a 2006 v6 limited with 84k miles. I just got it a couple months ago!

the dipstick is the worst ive seen in regards to a clear level, it smears all over everytime i check. but the majority of the oil is just below the top of the high dot.

I changed it myself and put 5 1/3 quarts in after draining. so i don't think there is too much oil, and if there is would 1/3 a quart extra make it bubble?

5 and 1/3 quarts, added to a fully drained engine should not, IMHO, raise the oil level high enough to cause cavitation. The only other probable cause for bubbles in fluid would be air entry on the suction side of the oil pump. Looking at the engine diagrams, the oil pump is located in the front of the engine, but above the normal oil level in the sump. There is a tube and screen filter that connects to the bottom of the pump, and extends down into the sump, to pull oil from the sump up to the pump. From the diagrams, it appears that there is an 'o' ring seal between this pick-up tube flange and the oil pump. Not having actually taken one of these engines apart, I can't say for certain, but it seems logical that if this pick-up tube flange were slightly loose, or the seal was not seated or damaged, it could cause the suction from the oil pump to draw some air in to the oil being pulled into the pump from the sump. The impeller gears in the oil pump could then create the tiny bubbles in the oil that you are seeing.

That being said, I can't be certain that these bubbles are not normal. I have never seen them when I check my oil level, but I always let the engine set a few minutes after shutting it off before I check the level, to let any excess oil in the upper parts of the engine drain down and get a more accurate level check. When I get a chance, I will have to try checking mine immediately after shutting down engine to see if mine does the same thing.

Maybe some others can add to the discussion with their observations.

 

[KMG]

I agree, I don't think I have too much oil in to be causing the bubbling. - Perhaps it's normal and I just need to let it sit a few minutes before checking.

If a seal was loose like you suggested, would there be any other problems i should look at?

I'm wondering if I need to have it replaced or checked out?.

Thanks for your help.

 

[TechWrench]

I agree, I don't think I have too much oil in to be causing the bubbling. - Perhaps it's normal and I just need to let it sit a few minutes before checking.

If a seal was loose like you suggested, would there be any other problems i should look at?

I'm wondering if I need to have it replaced or checked out?.

Thanks for your help.

OK, I checked both my '03's, a V6 and A V8, and when warmed up and running, both have small bubbles on the dip stick. I haven't ever checked it this way before, so I never would have seen them prior to this. And, they do dissipate shortly after the engine is shut off and the oil settles down. Given what I saw, I am suspecting that the presence of the bubbles are a normal thing. I would guess that the normal movement of parts in the engine, when running, is creating the bubbles. Unless someone else has any thoughts on this, I am thinking you don't have anything to worry about. Just let the oil set a few minutes after shutting the engine down, before checking the level, and you should be fine.:rockon:

 

[emoore924]

Just curious, did you change oil brands when you changed the oil?

Engine oils have anti-foaming additives in them and I wonder if brand A has more anti-foam agent than brand B...?

I had a similar experience when I changed the oil in my RV generator from Rotella 30W to NAPA 30W (was in a hurry and couldn't find the Rotella...) Had a lot more foam with the NAPA. Fortunately, it never seemed to hurt anything...but I'll be changing back to the Rotella on my next oil change.