2005 Dodge Grand Caravan Coolant Leak

3.8L engine, 75k miles.

Hello. My van has been having a heating issue for the past 2 weeks. I have heat while driving, but in idle it blows cool air.

Had Firestone run a pressure check while I was having my tires rotated today. They said it failed the test, but they were having trouble finding a leak. After about 2 hours, they told me the radiator is cracked and needs to be replaced with the thermostat for almost 600 dollars.

My van has never overheated, but the coolant has been low. Tonight, I topped off the coolant, ran the van for 15 minutes and after it cooled checked and it was noticably lower. But I cannot see any visible leaks.

I'm supposed to take my family on a trip to visit family tomorrow, and need to fix this myself.

Questions:
1) Does it sound like an obvious leak somewhere in the radiator? I don't have complete confidence in my tire place diagnosing this.
2) Is it a fairly easy fix to do myself? I found a radiator for 239 and it's on hold for me.

Any other tests, advice is appreciated. I need to get my family on the road.

Thanks! Richard i wouldnt replace the radiator just yet, something dont sound right here. it sounds like your losing a pretty good amount of coolant, and if there was a external leak, it shouldnt of been hard to find with a pressure test. and a pressure test only takes a few minutes, nowhere near 2 hours. if it truly 'failed a pressure test' but they couldnt find no leaks, id suspect a internal leak in the engine.

autozone and maybe some other parts stores where u are got a free 'tool loaner' program. if they got a cooling system pressure tester that u can borrow, u can check it yourself. basicaly u hook it up to the radiator when the engine is cold and pump it up to the system pressure shown on the radiator cap, which is 16psi for your engine. then u do a careful visual inspection of the underhood area. if theres a leak u should see coolant squirting out of the bad spot. dont forget to check the a/c drain on the firewall, if the heater core is leaking, coolant will drip out of the drain onto the ground.

if u cant find no leaks at all, theres a possibility u could have a bad head gasket, and this can cause the coolant to leak inside the engine, where u cant see it. the best way to diagnose that is to pick up a 'block test kit' at a parts store, which checks for combustion gas in the coolant. if its present, u got a bad head gasket or head.

id suggest doing the pressure test first and see if u find anything. then if not, try the block test. let us know what happens. Thank you for the help. I'm off to get the two tests now. I'll post what I find. I don't know why they said it was the radiator itself, if they ever saw it leaking. Would that be fairy easy for them to find? I'm wondering if they ever saw a leak at all. They went from Car Repair Talk's forum.