Hello. 2011 Camaro SS, L99 110K mileage. Week ago i've replaced VVT seal because it was leaking right onto the front main seal. That time after removal the coolant pump I replenished the "****" coolant fluid (vey cheap and strange color ). Today I added some discilled water and found that white signs appeared in the radiator refill hole.

With using cooling system cleaner I flushed antifreeze, then filled the water and flushed it, then added good coolant.

After driving a bit I found on the refill cap white spots again.

Could you please be so kind and advise that could be the reason ? As I understood, engine head could not be a reason due to its design.

 

Might be trans fluid. If it's engine oil might be the oil cooler in the radiator, if your car has one of those.

You're right, it would be very difficult, bordering on but not quite all the way to impossible, for anything internal to the engine to allow oil into the coolant. The other way, sure; but given that leeeeeks always occur FROM a place of high pressure TO a place of lower pressure, pressurized oil and coolant aren't close to each other in a way that oil would get into 16 psi coolant.

 

Yes I have separately oil cooler under the car.. unfortunately, an expensive part. Based on the photos, are you sure that this is oil? Could it be a reaction to antifreeze?

Can I temporarily shut off the antifreeze supply line to this radiator? Will the oil necessarily overheat in this case?

 

I am not sure that it is oil. It's "an oily substance", but EXACTLY what "oily" fluid it is/was, I can't be sure.

And:

Do you have an oil cooler in the radiator? What kind of car are we working on here? That's virtually THE ONLY way, in a LS series engine, that motor oil can find its way into the coolant. Only other possibility is a VERY low-probability crack in just the right place in the block (not even sure where that would be), all of which evidence ... forces one to follow paths of logic and reason, rather than blind wild speculation.

No. Not sure what that even means.

Of course not. Not any more than you can shut off the supply of fuel to the injectors, and it still run.

That would be among the least of your worries. With no cooling flow in the radiator, other things will overheat far worse and far sooner, which will park your car far before that becomes an issue.

Start with some logic. Keep the Gold Standard Of Troubleshooting firmly in front of you at all times:

"The simplest proposed explanation that fits all the facts is most likely to be the right one."

Let's dissect that wisdom one phrase at a time.
.

• The simplest proposed explanation ["simplest" means, the fewest assumptions, fewest convolutions, most direct path, ...]
• that fits all the facts [ALL the FACTS; if even ONE observed fact is left unaccounted for, then the explanation is wrong, or at best, incomplete; and put particular emphasis on the concept of "fits"]
• is most likely [not guaranteed, but certainly the first place to look, and then afterwards, proceed to less likely explanations in order of their likelihood; like, leave alien abduction as the very last proposed explanation]
• to be the right one. [the one that leads to a solution]

 

Thanks for the detailed answer

Yes it's L99 the common LS engine, LS3 mod with AFM and VVT.

-Can the round seals be the reason in my case ? I mean, can oil/coolant flow into each other or would I see it from the outside?


- I meant this T-hose that goes to the oil cooler (marked red and yellow). What if shut it off, drive several days and check the results ? Could the oil overheat in this case? I know that many LS engines do not have a separate oil cooler at all.

 

So not exactly "in" the radiator, but certainly, a point where water & oil come together.

Yes absolutely then, that can allow fluid exchange; in the direction of, FROM higher pressure (oil, 50 psi or whatever), TO coolant (16 psi or so). Coolant pressure is never higher than oil pressure except right after a hot shutdown, in this case, so you'd most likely never see coolant in the oil, at least not very much.

No the oil would not "overheat" if the cooler ceased to get coolant. Yes you are correct, the vast majority of LS engines don't have oil coolers, particularly not in the ½-ton trucks, of which there are about a billion, and they seem to get along just fine. The factory oil cooler is as much an oil WARMER as it is a cooler; oil needs to be hot, and engines suffer when it's cold, so factory oil coolers are intended in part to bring the oil up to temp quicker so that impatient people who want to romp on their cars before they're fully warmed up, will do minimal damage to them. Police cars are the object lesson in this situation.

That said, I wouldn't worry about any further troubleshooting. Seems like, since you have a water/oil setup, that it's highly likely to be the scene of the crime. Yes I'd suspect that if the seals are bad, you'd have a good chance of an external leeeek; but the cooler itself may have failed internally, like, cracked or something. O-rings, gaskets, etc. are cheeeep enough even if the cooler is kinda $$$; they'd be worth a try. When in doubt, swap em out. (say that 10 times as fast as you can ) I really don't see any practical way to "disconnect" the coolant from that; at least, not that's any less work than simply fixing it. Putting a truck oil cooler bypass block on the engine would be relatively eeeezzy though.

 

Thank you sir ! As I mentioned before, I mixed cheapest pink, red, orange coolants from the different suppliers, but now i flushed system and now it's orange. I will continue to monitoring situation under the radiator cap... Also I will drain some coolant for the oil signs inside.

Could you please advise, I have a couple questions more )))

What is the thermostat's opening temp ? Mine opens at 221F, so coolant temp travels from 192 to 222F. I've ordered the 160-thermostat and maybe this will help. Is in normal that mine opens at 221F ?
What is the fans operating temp ? Mine begins to operate at 221F... If this temp is too late, what I should to check ?

What is the max oil temp in the downtown with hard traffic on stock car ? Mine shows 115-118F and oil pressure 26-30 psi (depends on temp).

 

Anything could be mixed in with it since it’s a used car. My bro put P/S fluid in my moms mini van not knowing what went where. (Tranns went shortly later. Go figure. LOL). My point being who knows what could be in there.

 

Yeah, mixing coolant can produce some bizarre results. Although, the usual thing that's a big no-no, is mixing the green kind with the orange/pink one. 2 different chemicals. They're color-coded for compatibility. All of the orange/pink ones will mix with other orange/pink. What your pic looks like though, is some kind of oily something. I don't think it's from mixing coolant.

IIRC thermostat temp is given in °C these days, and I think it's like 92° or some such for these motors but don't quote me on that. (around 197 - 198°F) I don't think it's A Good Idea to put a 160° in a street-driven car.

Oil is at ALOT of different temps in different places in the engine. In the pan, it's usually not too far different from cooling system temp, one way or the other. 115°F doesn't sound right, that's about like lukewarm water out of your faucet, and I think you can just feel the dipstick and tell that it's WAY hotter than warm water. As far as "max temp", it could easily get up to 240 - 250° during sustained hard use on a hot day. It needs to be close to or above the boiling point of water, to keep it from collecting moisture, which of course is a major component of exhaust gases.

Oil pressure varies with temp & RPM. I'd expect maybe 20 - 30 hot idle and 50 - 55 hot cruising. Higher than that when cold.

 

OP- WHERE did you get the idea you can mix coolant types?? It's a recipe for cooling system disasters, like massive coagulation that clogs everything.
Expensive lesson....

 

I used to think that red orange and pink antifreezes are all the same thing and can be mixed. They were all labeled as G12 and G12+. Yes, it's my mistake. But now I flushed the system with radiator cleaner and then with dis-water

 

Where does the oil passes on this picture? I dropped both heads in January and replaced the gasket and bolts. I could not find the oil lines in the head. Some experts say that I have blown head gasket..

 

I attach new photos. I have driven for a 10 miles in the traffic and highway after cleaning the cap

 

Ok, finally i visited repair station. Engine technician smelled the radiator cap and advised that smells like a ATF. So, my main radiator is leaking.
Tomorrow I am going to check the tranny oil for coolant inside.
Ordered CSF 3414 Radiator

 

Pressurized oil does not pass through the head gasket; only drainback.

The gasket could leak coolant into the crankcase, but it's near impossible for it to go the other way.

Glad you were able to identify the fluid. It looked oily to me but hard to tell from pics what kind of oily fluid it was. The trans fluid cooler is a somewhat common failure point in cars generally, so nothing really weird about that. Probably much less $$$ & work to change the rad out than the kind of oil cooler your car has.

 

Thank you sir! Do I need to flush the trans oil? What is the possibility that coolant will fill the trans crankcase?

 

I have put circles where oil drainback occurs. This is the only place oil passes through the gasket. Oil lines in the heads? Oil gets to the valvetrain via the pushrods.

 

There is no drain plug on the 6L80 tranny, I drained about 3,5 fl oz from the bottom plug (level check plug). The oil found OK, it's a normal ATF and has a normal color.
I am tormented by the question: does antifreeze necessarily get into the transmission oil if the transmission oil gets into the radiator?
I drove like this for about 10 days, but the ATF turned out to be clean as mentioned.

 

A small amount, maybe. But if the fluid is still clear, then not enough got in there to cause any harm. It would turn the ATF into a pink powder looking mess of goo. It would be obviously messed up.