Question mysterious coolant leak

[shedevil]

I have a 94 firebird formula, I just took out the engine and had it rebuilt due to blown head. I have 6,000 miles on the new engine but it has had a coolant leak since it was put in. No coolant on the ground or on the engine it is all dry. I have to add a1/4 to 1/2 gallon everytime I drive it. New everything was put on. New hoses, pump,thermostat, everything. Only thing not new was alt. and manifolds and most eletrical. Please help sucks having new engine and having to add water. Spent 3 thou on rebuild and parts.

[cocobolo95]

Have you got any white exhaust smoke? That would say you have coolant entering the cylinder and going out the exhaust pipe. Have you checked for signs of a blown head gasket. Blown hg does not automatically mean coolant in the oil. A compression test can help diagnose blown hg. One cylinder low or 2 cylinders next to each other low. Run car with radiator cap off and look for bubbles in the rad coolant. Also a temp gauge that swings to hot and back down to normal, on a regular basis is a sign. Or overheating when all other causes have been eliminated

Did you put all the coolant hoses in their correct positions, that could cause problems. Did you bleed the system of air when you started running the engine.

Did you make sure heads were flat and no cracks, as well as, head sealing surface of block and check block for cracks.

[shedevil]

Car runs great normal exaust smoke no overheating problems runs normal temp never overheated.Had the engine put in 8 months ago only driven 10 -20 miles a day. Looked at all the obvious things did heater core all the normal cause of coolant problems. No dice

[USMC]

Pressure test the coolant system and se where that leads you

[shedevil]

Already did pressure test. Nothin

[USMC]

Shedevil,
Reading between the lines I assume you have checked all the obvious. This said lets start to think about whats not obvious. Because a press test yielded no results think and look at all coolant areas where any and all coolant passes through in one way or another. I am assuming this may be a pin hole leak that is evaporating where you cant hardly tell. Check hard lines and soft lines then recheck and then double check. Use a white rag/cloth when doing this as it will show any coolant. I once found a phantom hydraulic leak on an aircraft like this after several other Marines could not find it. Low and behold it was right in front of our eyes but we just could not see it. Try this and we will go from there.

[steveo]

it could also be that the cooling system was improperly bled (many shops do not know how to fill a reverse flow cooling system with bleeder screws). it could be burping.

have you read the proper instructions on how to fill the cooling system, and tried that?

1/4-1/2 a gallon is a TON of coolant and there is NO f$#ing way a leak of that size would be unnoticeable in form of a puddle or a trail behind the car

if you're concerned that it might be a head sealing issue, pull some spark plugs. either your oil will be milky, or your plugs will be eerily clean if you're burning coolant

[shoebox]

I'd look at all the plugs.