How many owners are seeing or have seen oil rear it's ugly head and
end up in the intake? Even if it's been fixed or went away.

GM has a service bulletin over the issue.
Z51 cars for sure, not sure how much the base car is affected.
My car had 1/4-1/2 cup in the intake after 2,000 miles.

I know of a few that added catch cans on the stock car.

Seems we have design issue. About 10 people Pm'd me for answers.
In less than a day in a less used section of the forum.

 

Almost 15K miles on my Z51 and 3 oil changes.

Not ONCE has oil in the intake been an issue for me. Then again, I was fully aware of the original error on GM's part regarding the amount of oil needed. And I have since ALWAYS insisted that no more than 9.5 quarts be added for any reason.

(and yes, I do have a catch can as well...)

 

What is a catch can and where does it go? Did you put it on or did the dealer?

 

its an aftermarket add-on can that you buy and install yourself. It allows filtering of the PCV system rather than it just being routed to the intake tubing as it is from the factory. Typically you would empty the catch can each oil change. This helps to keep your engine clean. The original design for a PCV system going back into the intake is to reburn oil fumes for better emissions standards. Good concept, but not for people who actually care about their cars performance and internal engine cleanliness..

 

This thread is to just talk about the issue. We are all Corvette family!

Only thing I'm thinking is.
If you are still getting oil in your catch can. Even with the correct level. I would say you have applied
a band-aid to the issue. No C7 should really need a catch can if it has no problem. Once your level
is between the hash marks it should stop. Are you catching oil in your can?

My dry sump gave me trouble barfing oil. Seems to still have had the issue even with the oil low on the hash marks. The issue can amplfiy once oil gets in there. I just fixed the dry sump issue! With help from a vendor that is very good.
If it burbs it goes back in the valve cover.
But I have another issue for the oil that has gotten it and my superchager tune does not like the oil.

 

Oil being puked into the intake due to an overfilled oil reservoir is a totally UNRELATED issue to oil fumes being present in crankcase fumes (which is what a catch can in the PCV circuit deals with)

 

>>>>This thread is to just talk about the issue. We are all Corvette family!
So lets keep this friendly.<<<<

I'm just a bit curious.
What did you read into Ken's Post to you that would make you respond with this comment? I understand that there a whole bunch of thin skin around here, but geez...

 

yes,
The puking was explained to me in that 2 oil pumps are used in the
dry sump system. The different volume's of these two pumps working together can cause the oil to catch air and cause the burp. Not depending totally on the oil level. GM did not do enough R&D on this engine.


Pretty heavy fumes to add up to ounces of oil in the catch can. That otherwise goes in the engine. Which can cake on the valves plus cause detination which really can cause more oil.
So with out the catch can everyone is getting oil through the heavy fumes.

 

So what stats are you privy to that allows you to come to that conclusion?

How many dry sump LT1s exhibit the problem out of how many actually produced?

 

I added that in now gone for the rest of the members not Ken.
Don't want the thin skin just more talk about the issue.

My rabbit liked the waffle hat. I see the pancake style has returned!

 

Trying to find out.

Numerous threads about oil coming back in aftermarket intakes. More than one have catch can like yours. Then GM has had many in for service with the issue. So many a TSB bulletin was produced to clean
them up and put back in service.

At least 2 large Forum parts vendor's have done extensive work to figure out the cause of the problem. The comments are the earlier engines.
of the LS series never ever had the issues of the lt1.
Which I know to true because I owned them all but an ls-2!
Several with blower kits! no issues!

It caused me a lot of greif. My car was on stands since July.
I can't take my car in because of the blower kit. They may lay the blame on me and blacklist the car. When a half cup of oil was poured out of my intake with 2,XXX miles. Before the kit! I am learning what I need to fix it. But GM put me in the position I'm in by having the issue to begin with. I feel I'm not alone!
Lucky I have another to drive.

 

Just under 3k on mine now with one oil change done by me and no oil anywhere that it is not supposed to be. When I first heard of the overfill issues I checked the intake and it was dry. I have checked it two more times over the last ~6 months and nothing.
Z51 car with dry sump.
S.

 

What has GM done about this issue? Does it involve both 2014 and 2015 Vettes?
Thanks for the info regarding the can and it's functions

 

The dry sump is mostly burping air that the oil scavenge pump brings into the oil reservoir with the scavenged oil. It may have some oil mist so I installed a clean oil separator that goes from the dry sump tank to the intake and condenses some of that oil mist back to the dry sump tank. Venting to the valve cover which, particularly with a turbo, is at a higher pressure would not appear to be the proper direction for air flow. You’re trying to stuff the air back in the crankcase or are you really having crack case pressure trying to go back to the dry sump tank! The dry sump tank is designed to separate the air so only oil not oil entrained with air goes back to the motor.
I keep my oil ½ quart low and added a catch can. The can is catching the blow-by from the crack case PCV system, nothing more. I have no oil problems.

 

Speaking of which, that raises a question I've wondered about.

With the reservoir system, what difference does it really make if the oil is a little low? It's not like it's a matter of the oil pump not being able to keep its intake submerged regardless of angle and/or g-forces as you'd have in a wet sump motor

 

I don’t think it has any harmful effect especially considering the bottom of the hatched area on the dip stick, which is about is about 1 quart low, is considered OK if slightly above. Even at sustained high rpm when more oil is in the engine, I assume the tank has all oil needed to supply the oil pump. It just means checking more frequently but since I have not burned any measurable oil in a year, perhaps some not measured when I changed oil, I don’t feel a need to check very frequently.
As you said, in a wet sump at high lateral g force a low oil level could cause air to be pulled into the oil pick-up. I recall my Datsun 260Z on a long highway entrance ramp I liked to take at high speed would show a drop in oil pressure near the end! Always made me a bit nervous, but didn’t stop me from doing it!

 

Low mileage here but I have checked the throttle body area twice between 1000 and 1500 miles and there wasn’t anything there, not even the minor carbon deposits commonly found there.

This is with a base A6 C7. Don

 

I recently drove to PA from south florida stopping in NC for a day or two first. On arriving in PA the total miles was about 1450. It was mostly freeway averaging according to the computer 74mph/24-25mpg. In Mechanicsburg Pa, I got a check engine lite and went to the dealer there who said I had oil on my MAS but would not service it under warranty since I had added an AIRAID air filter. I had to pay $101 as I was far from home and didn't have time to argue about it. I had forgotten about reading the issues concerning the oil burping and catch cans. On returning to Florida I noticed oil drippings on the floor and took it to the dealer where I purchased the car who said they have had several similar issues. They changed the oil and cleaned up the spillage and I haven't seen any further problems yet. I am going to install a catch can as soon as I can figure out which one to get. I am convinced that this is the reason I got the check engine light and have been waiting for almost two weeks for a call from Chevrolet customer service to see if I can get a refund on the service from the dealer in PA. who had said the filter voided the warranty and caused the oil on the MAS. I told him it was the dry non oil type but he still wanted payment. My dealer by the way has no problem with it and during the drive home, and since, there has been no check engine light. I even called AIRAID and they said the local dealers are even putting them on new cars prior to delivery on request. I am hopeful that there isnt to much oil barfed into the intake system during the 2800+ miles I put on the car. I put the air filter in at about 1000 miles just before I started the trip. My car has the Z-51 option with the dry sump. Any suggestions for the catch can? There are quite a few to choose from. I do have to say the PA dealership was very courteous and even washed my car which was filthy from the trip. I just feel their diagnosis was incorrect and I should not have had to pay for it. a catch can as soon as I figure out which one to get.

 

If you have a Z51 get a Catch Can for the PCV system but what causes oil in the air intake prior to the MAS is the burping of the oil reservoir tank. For that you need a “Clean Oil Separator.” See my above post. This is a picture PDF of my install of both for more info than you may want-look at the pics: http://netwelding.com/Catch_Can.pdf
I would also keep the oil ½ quart low, ~½ way in the hatched area.





Catch Can & Clean Oil Separator

 

Are we talking the air intake where the filter is or the actual intake mounted on top of the engine?

How do you check for this problem?