Bubbles on dipstick after oil change...?

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zerosoma

zerosoma

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Put some Castrol Syntec 5w50 in. It's pretty old. Half of it is SJ half of it SM. I also topped it off with some PYB (SN, 10w30).

For some reason whenever I pull the dipstick I see several tiny air bubbles in the oil.

Why would this happen? Is it because of the heavy 50w? It happens both after the vehicle is running or when it has been sitting idle for a half hour.

It's NOT overfilled, it's slightly below the F mark. I usually fill it TO the F mark on this vehicle.

What's the deal here? Should I be concerned?
 
I've seen it. Normal. Your checking it too soon after shutting the engine off. All you have to do is wait another minute or 2
 
Your Santa Fe is new enough that I'd dump the oil and put PYB in it. If you have high oil pressure and tight bearings, they may not get the lubrication and cooling fast enough, but I can't be sure.

Cars built after 2000 look good for a long time and engines are built to such tolerances that people are seeing value in babying cars today... A 2004!! Change the oil to what it says in your manual, I'd do it ASAP.
 
If you want to really have a pine needles discussion a oil too thick will tend to aerate and this is very bad for a lubricate in a IC engine. But you should be fine for a 5K OCI also the 5W50 should shear down to a 40 grade oil soon. Syntec 5W50 traditionally has not been the most shear stable oil. I have seen some UOA's it has sheared to a 40 grade within 1K miles of use and sometimes a 30 grade after some track time.
 
I agree with dave1251... I remember in class the teacher mention cavitation in the oil pan when the oil pump can't receive oil fast enough (it is thick and causes a void in the sump), but sends out the same volume as a thinner oil because it is a positive-displacement pump (gears that mesh to a tighter tolerance to expel the oil.) If the pump sends out too much there is a bypass valve to bleed the oil back into the pump.

Now, if you have air bubbles in your bearings they will touch and score the babbet and give you premature wear. Air in the oil, with what dave said, is probably very bad...
 
And as said before you check oil when motor is dead cold, example first thing in the morning after car has sat all night.
 
Originally Posted By: KB2008X
Yeah...what the Overlord said.

Keith


Clearance, thought if I mixed it with a little 30 w it would be fine. I'll be using it through the winter.

I checked it again tonight after letting it sit and there's no bubbles anywhere. I think we're ok.
 
Originally Posted By: Falken
I agree with dave1251... I remember in class the teacher mention cavitation in the oil pan when the oil pump can't receive oil fast enough (it is thick and causes a void in the sump), but sends out the same volume as a thinner oil because it is a positive-displacement pump (gears that mesh to a tighter tolerance to expel the oil.) If the pump sends out too much there is a bypass valve to bleed the oil back into the pump.

Now, if you have air bubbles in your bearings they will touch and score the babbet and give you premature wear. Air in the oil, with what dave said, is probably very bad...



But, the thing is - the oil is still a 5 weight when cold. So it's really not that thick unless you're talking above operating temp. I assume with the wide range of viscocity modifiers in this oil, it will shear down in no time. I don't think I should be worried.
 
Originally Posted By: zerosoma
Originally Posted By: Falken
I agree with dave1251... I remember in class the teacher mention cavitation in the oil pan when the oil pump can't receive oil fast enough (it is thick and causes a void in the sump), but sends out the same volume as a thinner oil because it is a positive-displacement pump (gears that mesh to a tighter tolerance to expel the oil.) If the pump sends out too much there is a bypass valve to bleed the oil back into the pump.

Now, if you have air bubbles in your bearings they will touch and score the babbet and give you premature wear. Air in the oil, with what dave said, is probably very bad...



But, the thing is - the oil is still a 5 weight when cold. So it's really not that thick unless you're talking above operating temp. I assume with the wide range of viscocity modifiers in this oil, it will shear down in no time. I don't think I should be worried.


Take a bottle of 5w-30 and take a bottle of 5w-50 put them both in the freeze, I can tell you which one is going to be like more like molasses. I've done this experiment myself. I know I wouldn't be running it during a SD winter if I liked my car. Its not the operating temperature I'd be worrying about, its the ambient temperature. Its not as thin as you think it is when cold, its actually very thick.
 
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I work around diesels and we do not even put 50 weight oil in them, 15W40 is what we run year round.....then again these are large diesels, not normal car diesels...but still

1991 Freightliner fuel truck, with a Cummins 10L I6 Turbo IDI Diesel, at startup it is 50PSI, once it warms up it idles at 25-30 psi, and only hits 50PSI under acceleration. That is on a diesel with over 4,900 Hours on it, possibly 14,000 (nobody knows if the 4 digit hour gauge has rolled, the company bought it used). If a worn engine like that has that high of a PSI, just think about what it is doing to that hyundai.
 
I agree Stephen, in that case the oil pump spends a lot of time in bypass mode trying to force the oil through bearing clearances and galleries not designed for that viscosity.

All the while the temperatures go higher and higher, cooking the oil and starving the engine.

How long would it take for this oil to reach the valve train I wonder, and how quick can it drain back down into the pan... If the drain holes are fairly small in the head it just might fill up under the valve cover...

Well, if he keeps 50 wt. in there, regardless, we'll all learn something.
 
Originally Posted By: Falken
I agree Stephen, in that case the oil pump spends a lot of time in bypass mode trying to force the oil through bearing clearances and galleries not designed for that viscosity.

All the while the temperatures go higher and higher, cooking the oil and starving the engine.

How long would it take for this oil to reach the valve train I wonder, and how quick can it drain back down into the pan... If the drain holes are fairly small in the head it just might fill up under the valve cover...

Well, if he keeps 50 wt. in there, regardless, we'll all learn something.


One must wonder what torutre the oil filter is going through.
 
Originally Posted By: motor_oil_madman
Always check oil on a dead cold engine.


Did you learn that from the owners manual of any motor vehicle or from BUBBA down at the Sinclair station?

I bet ya your current owners manual says "Hot a few minutes after shutdown".
 
Originally Posted By: zerosoma
tough crowd, lol.


Agreed. I'm not a huge thick oil fan, but I doubt that your oil choice is going to bring about magnetic pole reversal, or World War III (except maybe on here).
 
Originally Posted By: zerosoma
tough crowd, lol.


May i ask, what is your logic behind 5W50 in that vehicle?

For example on my sable it is speced for 5W20, but i know for a fact that 10W40 and 10W30 as well as 5W30 will work 100% in it, as that is what the engine was able to use way back in 1986, and the oil requirements are the same, 4.5 Q of oil and a FL400S filter, as well as the fact that the vehicle until the 2001 model year took 5W30 as the perfered oil, with 10W30 being an alternative that was 100% usable unless it got too cold. As such i know my 3.0 OHV V6 will run fine on most oil, i plan to switch back to 5W30 after this round of 5W20, a bit of startup rattle is occuring.
 
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