How much coolant in the heater circuit

Hi,

I have some trouble with my Lumina, after I replaced the tensioner, elbow, lower LIM gasket and other gaskets we drove to vacation all was fine (around 1200km).
Now, 2 months later my wife uses the heater because we have winter, now we can refill coolant ones a week round about 1/2 Liters.
I've put paperboard under the car to see where the cooling water runs out, but there is no stain.
Oil level is perfect, and there is no coolant in the oil.

So my theory is there was air in the heater circuit which I didn't see because we did not used the heater. Can anybody tell me how much water is in this circuit?

Not very much in the heater core. Maybe a pint.

Ok thanks, I found this text in repair manual:

The heater core heats the air before it enters the vehicle. Engine coolant is circulated through the core to heat the outside air passing over the fins of the core. The core is functional at all times (no water shut-off valve is used) and may be used to temper conditioned air in the A/C mode, as well as the heat or vent mode.

So there can not be air in, when I changed all the stuff.

But where is the coolant?

Not very much in the heater core. Maybe a pint.
In addition to the engines cooling system.The heater core circuit is an extension of the engines cooling system. When you changed the "LIM' gaskets and refilled the system you had an appreciable amount of air in the system whether you know it or not. The air stays in the high point of the cooling system. That air needs to be bled out of the system or you'll have alot of problems, possible overheating to say the least. If you werent aware of this and didnt manually bleed it out, the car will after driving it a distance and youll notice the cooling system level coming up short. Refill it, run the engine to temp and check for leaks. Better yet pressure test the system. That air creates steam in the system. That steam builds to a high level of uncontrollable pressure and can do damage if not purged right away. I've seen radiator seams split and tanks exploded by it. Any number of gaskets can be damaged and intake manifolds too. On the other hand maybe youll get off light and only the radiator cap is bad. What problem did you have before you did this work? HTH

Before I changed the Lim gasket I lost a little bit of coolant, 200ml in a month, an we using dec cool and the engine had the origin gasket kit, then I have done the job. replaced gaskets, a new upper intake manifold, then the elbow from lower intake manifold broke so I have replaced this one too. The tensioner screw was broken too so I have replaced the whole thing.

I bleed the air with the small screw on thermostat. The confusing thing is, why I can drive 3 month over 1700km and all seem to be fine, and now on cold wether the water is leaking.

I have replaced the radiator cap too, because it was the origin too.

Couple of questions:

You say you replaced these parts....did you actually do the jobs or did you pay someone else to do it?

I'm assuming this is a 3.8L?

The usual leaks are the w/p, upper plenum, plastic elbow to lower intake, throttle body gasket, radiator, radiator hoses, heater core hoses, heater core.......

You are obviously losing coolant, because you are constantly adding to the reservoir.....

Does the car overheat on the gage?

When you turn your heat on, do you get good heat, or are there cycles of times where the heat diminishes or even goes cold?

If done correctly, the lower intake gaskets, the upper plenum(and gaskets), and plastic elbow eliminates those problems......

Heater core would be indicative if you get a sweet smell from the vents during heated air flow, or loss of heat.......

Air pocket would be indicated by overheating condition or loss of heat from heater core....neither of which you indicate....

Others have suggested a pressure test, which is a good idea.....however, some leaks are so small and tend to leak only when under pressure AND hot......lots of times the leaks are so small, that as you drive the vehicle down the road, air flow and vibration, and evaporation can leave little evidence of a leak.....in cases like this, adding coolant dye and the use of a black light is invaluable....

You need to pressure test the cooling system to the pressure shown on the radiator cap. There may have been a secondary leak developing that hadnt shown obvious signs yet or some thing may have gone amiss,hose, clamp,gasket seating,radiator seam,etc. Pressure test should give it up. Was car ever seriously overheated?

Couple of questions:

You say you replaced these parts....did you actually do the jobs or did you pay someone else to do it?
All repairs I did these by my self and uses repair manuals

I'm assuming this is a 3.8L?
Yes

The usual leaks are the w/p, upper plenum, plastic elbow to lower intake, throttle body gasket, radiator, radiator hoses, heater core hoses, heater core.......
Thanks...

You are obviously losing coolant, because you are constantly adding to the reservoir.....
Yes I did, today we have not using the heater, so I have to look if the engine cold if we loose coolant again.

Does the car overheat on the gage?
No, the car have never overheated.

When you turn your heat on, do you get good heat, or are there cycles of times where the heat diminishes or even goes cold?
If the engine warmed up the the heater is working perfectly

If done correctly, the lower intake gaskets, the upper plenum(and gaskets), and plastic elbow eliminates those problems......
I did that job on my other Lumina so I think I did it correctly, new elbow, new gaskets...

Heater core would be indicative if you get a sweet smell from the vents during heated air flow, or loss of heat.......
Thanks to my wife we using perfume cans which smells like strawberry, very hard to smell the coolant.

Air pocket would be indicated by overheating condition or loss of heat from heater core....neither of which you indicate....
shit :D

Others have suggested a pressure test, which is a good idea.....however, some leaks are so small and tend to leak only when under pressure AND hot......lots of times the leaks are so small, that as you drive the vehicle down the road, air flow and vibration, and evaporation can leave little evidence of a leak.....in cases like this, adding coolant dye and the use of a black light is invaluable....

I answered your questions in upper quote...

Edit:

Did it, the coolant comes from the radiator, driver side.

I think its from the drain plug, but I have to wait till tomorrow that I have daylight.
Which is the most radiator failure point?

What is the different of the thickness of the cooler?

5/8" and 15/16" ?

Another issue can be "cold water seeps"...those that only leak when cold and NOT under pressure...usually get worse as the weather gets colder.

Luckily they are usually related to something simple, like a loose clamp or a clamp with a stripped screw. Sometimes o-ring-type seals do this too.

They happen because the rubber of the hose contracts and hardens the colder it gets, and if not under the correct compression to form a seal with the other surface, they leak. When warmed up they get more compliant and expand slightly, stopping the leak.

They can be a bitch to locate sometimes...they can leak into an area that traps the dripping coolant, so you never see it on the ground, then rolls out when the car is moving. Any residual usually dries up after the motor is warmed up, and you see nothing. That reminds me, am I the only one who has noticed that DexCool is not good for leaving much visual evidence of a leak? Ol' green stuff use to leave a tell-tale white trail back to the source even if dried up....Dex doesn't seem to so much...