I was driving my 04 coupe for 10 minutes and parked it a detail shop. Car is driven about once a week with 80k on it. Car sat for about 10 minutes off in the parking lot with no noticeable leak. I left and then got a call 45 minutes and the told me they moved the car about 20 feet and let it idle and all the coolant is leaking out everywhere.

I get there and notice the radiator and reservoir tank empty. All the coolant has leaked out. Looks like there was coolant on top of the reservoir by the outlet. The outlet is facing the passenger headlight. Dried coolant seemed to be on the passenger headlight.

Could the thermostat fail and with the cooling system pressurized that cause the coolant to leak out through the reservoir outlet?

No coolant was available for purchase so i filled the radiator / reservoir with water and drove 3 miles home. There were no leaks. I then let it idle for 10 minutes with no leaks. Then drove for a another 3 miles uphill and no leaks. If a hose or radiator was crack there should be a continuous to leak, right? There is probably air in the system now and will need to get a coolant service to replace the water.

Any ideas? Thanks

 

One sure way to find the leak is to have the system pressure tested! If the thermostat was bad you'd be overheating within the first mile! Any quality shop/mechanic can pressure test your system, no reason to visit the dealership!
Gary

 

Thanks. Would the coolant leak have cause the "engine service soon" light to come on too? Or is that possibly the gas cap not being tighten?

 

Loose gas cap could be the cause of the ESS warning light! Did you have your cooling system pressure tested to find the leak?
Gary

 

I'm getting the tester this weekend. Thanks

 

Just did the test. Stop the gauge at 15 psi. Had it on for about 3 minutes. I didn't see any leaks. I'm wondering if it was the radiator cap not sealing properly and then the system relieve the pressure through the reservoir. Can that happen with a bad cap?