Coolant leak 2001 Nissan Sentra

I’m having trouble with overheating. I think I’ve had a coolant leak for sometime - as the reservoir empties out. I had the radiator replaced last year about this time. I took it to the shop last time and they added coolant everywhere but said they couldn’t find the leak. When the temp gauge went up this time I bought pre mixed coolant and filled the reservoir - also filled the radiator. Now I see a lot of green fluid coming out from under the car, after driving a few miles and running the AC. Did I mess it up by adding too much to the radiator? Thanks for any info.

It should be easy to find the leak now. Check under the hood. If the coolant is not coming out of the overflow tube of the reservior, then you have a leak somewhere. This is probably the leak that is causing all the problems.

Did I mess it up by adding too much to the radiator?
No. Normally the radiator is full with any excess from heat expansion going to the plastic reservoir. So it is impossible to overfill the radiator and cause any harm in a properly operating cooling system.

If you have an external leak, you (or your mechanic) will have to visually track it down to its source and repair accordingly.

Thank you for the information! I took it in today and apparently the radiator is leaking - and the hoses need replacing. Luckily the radiator is still under warranty. I’m glad I found your site. It’s very helpful!