Very low coolant, concerned

[oddball]

@JSolo I had to read that twice.

First thought was, "I dunno dude, there was this one gal at o'reilly that was awesome, but I've never met a female parts counter worker other than the paperwork pushers....."

 

[JSolo]

Yeah, but the gal from the dealer didn't come with strings attached, was low maintenance and poured freely.

 

[Scorpion24]

How often does everyone top off their coolant?
I topped off last September. And I had to again recently. I get white smoke at cold start but I thought it was just condensation.

 

[777David]

In the 2.5 years I've owned mine, I've topped mine off twice. Just checked it again last night and it was still good, but a little lower than when I previously topped it.

 

[JSolo]

I don't think i've topped mine off since sometime in 2022. It's slightly below F now when cold, but not by much. Car has 11Kmi now.

 

[lil_lurking_stinger]

How often does everyone top off their coolant?
I topped off last September. And I had to again recently. I get white smoke at cold start but I thought it was just condensation.

No one can say for sure besides topping it off if you notice it’s low. It all depends on how much you drive, your outside climate and what you do while driving to find out.

Just leave it to your mechanic/dealership to check when you go for services.

 

[JSolo]

^^Too much confidence in the service dept....

 

[Volfy]

Bear in mind this is the expansion reservoir. Even if the coolant level drop to the bottom when cold, the cooling system will still function normally.

Even if you need to top off occasionally, the amount is tiny compared to the overall coolant volume in circulation.

As long as there are no other signs of abnormality, like milky engine oil, there is no real concern.

 

[Scorpion24]

Bear in mind this is the expansion reservoir. Even if the coolant level drop to the bottom when cold, the cooling system will still function normally.

Even if you need to top off occasionally, the amount is tiny compared to the overall coolant volume in circulation.

As long as there are no other signs of abnormality, like milky engine oil, there is no real concern.

some good points. Both times I topped off there was still some coolant at bottom of visible reservoir. No milky residue.

 

[Volfy]

some good points. Both times I topped off there was still some coolant at bottom of visible reservoir. No milky residue.

Yes, if there is something else worse that is causing consumption of coolant, the car will show other signs to let you know about it. The white "smoke" on cold starts is just water vapor that condenses into tiny droplets in the still-too-cold exhaust. If that was really coolant leaking through blown head gasket, your coolant level will likely drop way faster. Plus some of that coolant that get sucked into the combustion chamber will make it into the oil sump and turn the oil milky.

There could also be signs of cross contamination of oil getting into the coolant as well.

And if there are leaks, you'd smell the distinctive sweet scent of glycol, either in cabin or when you pop the hood to a hot engine.

 

[JSolo]

Bear in mind this is the expansion reservoir. Even if the coolant level drop to the bottom when cold, the cooling system will still function normally.

Up until the point when the reservoir runs dry and radiator starts sucking air in.

 

[LordKOTL]

How often does everyone top off their coolant?
I topped off last September. And I had to again recently. I get white smoke at cold start but I thought it was just condensation.

Mine was at the low mark at the 600 mile 1st oil change; topped it to about midway up the dipstick scale.

No issues since--hovering around the same level; if this changes when I do my 12k oil change tomorrow I'll repot back.

 

[Volfy]

Up until the point when the reservoir runs dry and radiator starts sucking air in.

Of course. The point was that the expansion tank is there to allow the coolant room to expand/contract. Just because the coolant level is at the "MIN" mark doesn't mean the coolant is "very low" and a cause for grave concern. It just means it's time to top it off a bit.

IMO, the reason a lot of Stinger owner are not used to the coolant reservoir level changing is because Stinger's coolant system uses a RECOVERY type coolant reservoir. This means the reservoir sees the same coolant pressure as the radiator, which is why the cap on the reservoir and the radiator cap have the same warning label. This means the coolant in the recovery tank is pushed back and forth, as the coolant expands and contracts. So, if the total coolant volume (2-3 gallons) in the system loses a few fl. oz, that drop is easily seen in the recovery tank.

Not all coolant systems are like this. Some coolant reservoirs are of the OVERFLOW type. In those systems, the reservoir doesn't see the same pressure as the radiator and will only receive coolant from the radiator if the pressure exceeds radiator cap's vent valve setting. In those systems, the coolant in the reservoir is not in constant communication with the rest of the coolant system, so the level doesn't drop much over time. You can tell if a car has that type of overflow reservoir, by the simple non-pressurized cap it has.

My GMC Savana is like that. The OVERFLOW reservoir sits on top of the engine, above the radiator. However, I can open the radiator cap and even if the coolant level in the radiator is low, the coolant in the overflow reservoir will not back flow into it.

 

[JSolo]

^^I could have sworn i've removed the reservoir cap on a hot engine without the level changing. If such was not possible, I'd expect the reservoir cap to be of significantly heavier duty design.

 

[Volfy]

My guess is that's why there is that long stem tied to the inside of the reservoir tank. When fully closed, it depresses a valve that opens the reservoir to the radiator line. I could be wrong, of course, but that long stem must serve some function related to how the reservoir operates.

 

[JSolo]

I thought it was just a level as there are L/F marks on it. It's awfully flimsy to be depressing anything. I will explore next time I drive the car.

 

[Volfy]

FWIW, those L/F marks on the stem are kinda goofy. Every time I've pulled the cap, I could not tell what level it's on that stem. Besides, the translucent tank kinda makes the marks on the stem rather pointless.

Yeah, I'm not 100% certain either. Just some educated guesses from looking at it. I am quite sure that it isn't a simple OVERFLOW type reservoir. It is possible that this reservoir is one of the two remaining types:

1. EXPANSION type that sees radiator pressure, or...

2. RECOVERY type that can return coolant only after the system has cooled down and is no longer pressurized.

Probably No.2 is more likely. Either way, the reservoir level will ebb and tide with the overall coolant volume in the coolant system. That I'm quite certain.

 

[D.J.]

FWIW, those L/F marks on the stem are kinda goofy. Every time I've pulled the cap, I could not tell what level it's on that stem. Besides, the translucent tank kinda makes the marks on the stem rather pointless.

Yeah, I'm not 100% certain either. Just some educated guesses from looking at it. I am quite sure that it isn't a simple OVERFLOW type reservoir. It is possible that this reservoir is one of the two remaining types:

1. EXPANSION type that sees radiator pressure, or...

2. RECOVERY type that can return coolant only after the system has cooled down and is no longer pressurized.

Probably No.2 is more likely. Either way, the reservoir level will ebb and tide with the overall coolant volume in the coolant system. That I'm quite certain.

2

Our stinger rad cap + overflow reservoir works like this - nothing fancy or new.

 

[JSolo]

@Volfy I forgot to check while the engine was running, but I did peek under the hood.

The rod you refer to is way too flimsy to depress anything. I dont know why its even there. Easier to see level on the side than on the rod.

The radiator cap has a pressure marking on it - 1.1 (bar or atm?). The res cap has no such markings. Im with DJ on this, always assumed it was just a traditional system - expanding coolant opens pressure release valve to raise level in res when hot. As it cools, vacuum valve opens allowing fluid (or air if low) to get sucked back in.

I still don't understand why in many years of driving numerous cars, this is the first one where coolant has to be topped off on a somewhat regular bases.

 

[Volfy]

Yeah, I just got home and had another look at it... definitely type 2 (recovery tank). That reservoir cap is too flimsy to be pressure bearing. The internal rod still looks goofy. If this were a black tank you cannot see through... okay.

BTW, mine shows 1.4, which I'm sure it's 1.4 bar, or 20psi. Sounds about right for the cooling system pressure.