Coolant Disappearing, need help

[Dinows]

Until he does a pressure test and the stuff mentioned here, there is not a lot of use rehashing everything. Everything can't be okey dokey and coolant still vanishing unless it's something obvious like a bad radiator cap blowing off early / when pressure rises for a few minutes after shut off.

 

[Dinows]

If the coolant was leaking someplace which it is, wouldn't the coolant in the resivore be going someplace, when I pump up the pressure ? But although the pressure wont hold, the level of coolant in the bottle doesnt go down ! Very strange

 

[cyclops222]

Have you found coolant in the crankcase ? Or on the dipstick ? looks like coffe with cream mixed together. Not very likely with all the gallons you have added so far.
Buy some RED liquid food dye. There is a risk that some red water will leak put onto engine or bilge floor.
99% is going to probably be sucked into a cylinder or 2 or 3 and stain them nicely. DO NOT start the engine the next morning. Pull each spark plug to see if a cylinder head or intake gasket is sucking out the coolant.
You say the engine starts perfectly in 2 seconds of full speed cranking ? Or does it crank slowly and stalls a lot ?

 

[cyclops222]

Are there exhaust Flapper Valves in the exhaust system ?

 

[cyclops222]

There is a possibility that a gasket is allowing running engine VACUUM to suck the bottle down. It can be cylinder head gasket vacuum leak when heated up only. Or even the intake manifold if it has engine water flowing in it. The gasket MAY reseal as the engine cools down. Been there on that one. a Honda.

 

[alldodge]

If the coolant was leaking someplace which it is, wouldn't the coolant in the resivore be going someplace, when I pump up the pressure ? But although the pressure wont hold, the level of coolant in the bottle doesnt go down ! Very strange

Look real close at your plugs, are there any that are cleaner then the others as more white

 

[Scott Danforth]

If the coolant was leaking someplace which it is, wouldn't the coolant in the resivore be going someplace, when I pump up the pressure ? But although the pressure wont hold, the level of coolant in the bottle doesnt go down ! Very strange

If there is a leak, the motor probably can not make pressure. If it does, then the system is drawing in the raw water vs coolant from the puke tank

Have your heat exchanger pressure tested (and repaired if needed)

 

[04fxdwgi25]

Coolant has 3 places to go when level is going down.
In the engine (head gasket or crack or manifold)
In the bilge (hose, fitting, crack (again) or radiator cap)
In the exhaust (crack again (manifold, but that would show in the engine through exhaust ports) or leaking heat exchanger)

Doesn't just vanish.

He stated not in the engine and none in the bilge so that potentially leaves 1 other option, unless engine is burning it off

 

[cyclops222]

What is the remaining 3 rd possibility ?

 

[Bondo]

If the coolant was leaking someplace which it is, wouldn't the coolant in the resivore be going someplace, when I pump up the pressure ? But although the pressure wont hold, the level of coolant in the bottle doesnt go down ! Very strange

Ayuh,...... You need to drain All of the coolant, the bottle, the exchanger, 'n the block,....
Then pressurize it, 'n Listen, to locate the source of the leak,.....

 

[04fxdwgi25]

What is the remaining 3 rd possibility ?

There, fixed it:
Coolant has 3 places to go when level is going down.
1. In the engine (head gasket or crack or manifold)
2. In the bilge (hose, fitting, crack (again) or radiator cap)
3. In the exhaust (crack again (manifold, but that would show in the engine through exhaust ports) or leaking heat exchanger)

 

[alldodge]

There, fixed it:
Coolant has 3 places to go when level is going down.
1. In the engine (head gasket or crack or manifold)
2. In the bilge (hose, fitting, crack (again) or radiator cap)
3. In the exhaust (crack again (manifold, but that would show in the engine through exhaust ports) or leaking heat exchanger)

Heat exchanger as Scott mentioned

 

[04fxdwgi25]

Yeah, that's what I mentioned back in post #5