About 2 months ago, I had a leak in my radiator. I replaced the radiator and topped off the coolant. Drive for a week or two and notice the temp gauge creeping up so I bypass the leaky heater core and top it off again. No more cooling problems for 5 or six weeks.

So this past Monday evening, 'seafoamed' the intake (saw a noticeable improvement right away!) Drove it around for about an hour, temp gauge exactly where it should be.

Next morning, I'm driving to work and the temp gauge pegs over in the red. Radiator is bone dry. I put 3 big plastic jugs of coolant in it and it is fine for the rest of the week.

There are no signs of leaky hoses, no puddles or drips in the driveway, and the heater core has been bypassed. There is no steam/white smoke from the exhaust. So what should I look for/test to figure out where the coolant is disapearing to?

 

look at your oil....does it look like chocolate milk and is it high on the dipstick?

Sounds like a headgasket

 

If you re-used old hoses it is possible that you tore a grove on the inside of the hose in the end that will leak under pressure.... I've had it happen to me