Anti freeze consumption: How much is allowed?

[ARCOgraphite]

My wife's fairly new toyota 4 banger would leak a bit at the water pump during winter season during below freezing starts.
This loss went away when the ambient warmed up.

Our new 2022 Subaru (sold) "dissapperared" almost the complete
overflow bottle after 10 months in service across a hot summer season.

My Ford system which is sealed, seems to "dissappear" a half litre a year.
last UOA showed no "K" in the oil.

Is the presence of potassium still a reliable indicator of coolant in the oil?

New-ish subaru outback coolant overflow bottle near empty -

 

[Greasymechtech]

EG/water evaporate and is not an opinion, but a fact. So, its very normal. Its not a sealed system and breathes.

Problem is, when serviced at quicklube/dealership/indie, unless vehicle was parked there overnight, when vehicle is hot and lubetech looks at level, its full from fluid/heat expansion and doesn't get topped off ever.

Top it off cold and don't worry about it. When it becomes a problems, you'll know. Leaky hoses, radiators, water pumps, and manufacturer errors are what you need to be aware off concerning your year/make/model/engine.

 

[Hall]

Check the owners manual where it refers to the overflow tank. Most simply say keep the level between the MIN and MAX lines and doesn't tell you to run to "your authorized dealer for repair" if some needs added.

 

[xspeedy]

I have a 2020 RAM 1500 with the 5.7L and I started to notice an obvious coolant smell around the front grill of the truck after a drive. I pressure tested the system myself (though not the cap) and am not seeing anything obvious. I even left the pressure on the system overnight to see if I could spot anything dripping on the ground or around the enigne bay (no hot engine to boil off the water that does come out) and nothing. Searching the forums, the consensus seems to be it is just stuff venting out of the overflow tank which is not sealed and has a rather loose fitting pop cap on it. I do have to put a few ounces of premix in every now and again.

 

[ARCOgraphite]

EG/water evaporate and is not an opinion, but a fact. So, its very normal. Its not a sealed system and breathes.

Problem is, when serviced at quicklube/dealership/indie, unless vehicle was parked there overnight, when vehicle is hot and lubetech looks at level, its full from fluid/heat expansion and doesn't get topped off ever.

Top it off cold and don't worry about it. When it becomes a problems, you'll know. Leaky hoses, radiators, water pumps, and manufacturer errors are what you need to be aware off concerning your year/make/model/engine.

My Ford has a 21psi rated screw-on cap on a clear polymer expansion tank and no vent - so I would guess this is not an open system - I am guessing the hot coolant inflow from the RAD just compresses the air bubble in the expansion tank

 

[Greasymechtech]

Put a pressure gauge on it and see how often it runs up over 21 psi. Also, when cooling, use a vacuum gauge to see how often it pulls from the atmosphere, if it will ever show vacuum and simple sucks up when cold.

On a new engine, I've found that too many engines need numerous/multiple heat cycles that are needed to burp out any manufacturer 'air bubbles'. I just don't see the coolant level perfect from the factory or dealer prep. Top it off.

Another is the 'expansion' of brand new coolant hoses throughout the engine. There will be an initial expansion stretch of hoses when new. That expansion will require a little coolant too. Top it off.

The dealer can't do this because the engine is usually hot when you bring it in for service. So, they see a fullish level.

None of my bottles have ever come close to empty. Seems like foolish trust of an automaker or dealer, or a negligent owner.

On both the purchased new 2019 and 2021 in the driveway, both had an initial coolant level drop, if not excessive. Both had 'cold' full top off needed a few times during the 1st year of driving. After that, there won't be much more hose expansion, or small bubbles burping to the top or degassing, depending on the 'bottle system' and 'pressure cap' location. Haven't topped off any since, other than when drain/refilling for normal coolant service, where it takes a little to 'degas' all the air bubbles/pockets that formed during the service.

Leaks are noticeable if someone(owner or dealer) is competent enough.

Too many poorly informed consumers think that the new car is perfect and cry/whine/complain excessively over a low bottle a year later. TOP IT OFF! Monitor and inspect often when cold.

Got rid of one 2gr waterpump under warranty before 5/60k, and a new Mazda 6 radiator about a month after new vehicle purchase, both losing a quart every couple weeks. Currently don't own any known 'block porosity', 'questionable head gasket', or pathetic 'block design', head gasket eaters and don't use OE coolant that caused the known water pump leakage.

 

[Nesterenko]

Try marking the coolant level on the reservoir with a piece of tape with the ambient temperature and date marked on the tape first thing in the morning. Check again at a later date under the exact same conditions. I believe the level will have changed slightly, it's normal.

 

[gregk24]

My Honda’s and VW’s have needed occasional coolant top offs. None of them have / had leaks. Whether it’s due to to air bubbles or evaporation I don’t know, but a top off here and there has been normal in my application.

Edit: our 2014 Jetta had a small seep from the water pump, I had to top off before and after replacement of that part though. Very little coolant was lost from the seep. My guess is evaporation.