Just wondering if this is normal, Im guessing its not so normal.
The bubbles are on the dipstick after any bit of stick I give the car in the 5k to 6k rpm range.
The engine also gets a little more valve train noise after some time, not horrible but more than when kept at low revs for a whole drive, is that just heat or bubbles?. It makes me wonder if the bubbles are getting into the oil pickup and shortening the lifespan of the engines internals
Im using 5w30, have used 0W40 and 10w50, with similar bubbling results, just a marginally different valve train noise.
The motor is an LS1 with medium cam, raised compression, double valve springs, patriot heads, extractors, melling oil pump, after market gated sump, retained stock splash guard in the sump, relocated oil filter, 6400rpm rev limit.
Any replies welcome even if its for a stock LS that is regularly put into same 5k - 6k rpm range.

 

Likely, pickup tube O-ring. Lets air get sucked in, replacing some of the oil it should be sucking.

 

The noise is probably air in the lifters. Aerated oil does not offer the protection your engine needs.

Edit: I got rid of the incorrect part. I misinterpreted the source information, then I regurgitated it without thinking. Awfully dumb on my part.
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What oil are you using?

 

thanks for the replies, the oil is castrol edge A3/B4 5w30, but it has been doing the same bubbling with the previous 2 oil changes which were different viscosity and brands (mobil 1, penrite).
2 months back the sump was off due to oil leaks and I told them to check the oil pickup and its o ring while its open because I was concerned about the valve train noise.
Pseudonym, maybe im off, but how would a oil pan gasket possibly aerate the oil? there is slightly positive pressure in the sump so a leaky gasket would only let oil or crank case gasses out right?
Existing concerns that may or may not have anything to do with the bubbles are:
- There is still an undetermined slow oil leak somewhere.
- During the sump swap the dipstick tube length was an estimate, and there is the chance the oil level is too high, if this is the problem how would I know how much its off anyway?
Thanks again for the replies.

 

Doesn't matter what oil.

Doesn't matter if the pan gasket leaks. (it'll let unpressurized oil OUT, except if it's near the cooler loop in which case it'll be pressurized, but has no way to let air INTO the oil pre-pump, i.e. suction, i.e. turn the oil into foam)

Same for the dipstick tube. If it, or its O-ring, has a leak, it'll let oil OUT, and it'll be ALL OVER the block and pan and starter and whatnot all down there, NOT let air into the pressurized oil stream on the suction side of the pump in such a way that it could aerate the oil.

Could be overfilled crankcase. However in that case d00d would probably be on here posting about "it took 9 qts to fill my crankcase, is that normal", or some such; NOT "my oil is foamy". FOCUS.

Could be a cracked pickup. Not common, not the first possibility to consider, but definitely COULD BE that. If I were to tear the thing down to the point that I could look at the O-ring, and it turns out to be fine, then that would probably be the NEXT thing I'd look at. AFTER the O-ring.

Same for cracked block. It would have to have cracked in a non-stressed place, in just the right way as well as just the right place, without creating any other symptoms. Not saying it can't, or won't, or never has, happened, or never will; only, that it's WAAAAAAAAAAAAYYYYYYYYYYYYYYY DOOOOOOOOOOOWWWWWWWWWWWWWWNNNNNNNN LOOOOOOOOOWWWWWWWWWWWWW on the list of LIKELY proposed explanations. Otherwise d00d would be on here posting about knocking noises, metal chips in his oil, visible cracks he can see, glitter in his oil filter, etc. Not saying that's NOT going on, only, he DIDN'T post about any of that. He posted about foamed-up oil. Let's FOCUS.

"The simplest explanation that fits all the facts is most likely to be the right one". In this case, emphasis on "simplest", "all", and "most likely". Pickup O-ring first; alien abduction, Elvis sightings, demonic possession, divine retribution, let's save all that stuff for later. Concentrate on MOST LIKELY.

Pickup tube O-ring.

 

IS your oil pressure dropping after a few seconds? I had this issue of air in oil. Pressure was good till about 6k then it would gradually fall. My issue was a little piece of what looked like a paint chip was stuck on pickup tube. Its was approx 1/4 inch square.

 

RB04Av and Simond thanks for pointing out the mistakes in my previous post. It has been edited.

 

Ok,
@RB04Avand @Fishmasterdan,
I dont have a dash oil pressure gauge, just a low pressure alarm, but its set to about 12psi.
So I can run my scanner and log the oil pressure and rpm to see what happens for the next drive.
Would a cracked pickup tube or o-ring even show low oil pressure in strange places?

 

With a leak on the suction side of the pump, allowing the pump to suck air instead of oil, the pressure will be low at all times; just how low would depend on the severity of the leak. The thicker the oil the worse the problem will be, since the leeeeeek would preferentially allow air into the pump rather than atmospheric pressure forcing oil into the evacuated pickup tube as the pump moves whatever is in the tube, out of it.

Versions of Fishmaster's problem happen to people all the time. A REAL COMMON source of that is people spoooging up their gaskets too hard with RTV, and it squirts out toward the inside of the motor and solidifies, then over time comes off and lands in the pan; and cleaning old gasket material off of surfaces carelessly, and letting flakes of it fall in. Doesn't happen all that much to factory engines but is common in rebuilds or after people have worked on them or whatever. Was worse on older engines due to the nature of their gaskets, isn't as common in these engines but with a used one, you just never know. Butt, won't cause foam in the oil, generally; just poor oil flow and consequent starvation and low pressure, especially at high demand (high RPM), just as he described.