Okay, so I recently installed a built D16Z6 into my hatch, I used the stock D16Z6 radiator which is a year or so old. I'm losing coolant and I can't see where. I don't think there is a head gasket leak because there are no bubbles in the coolant, the oil looks fine, and there is no white smoke coming from the exhaust pipe. And as far as I can tell, there are no noticable leaks. If the cap is bad how do you know? Does it release coolant? Is there some type of leak test I can have done on the cooling system? Thanks guys.

 

It could be going a variety of places. How much coolant are you losing/day?
My dad had a cracked head on our Ranger and it sucked about a gallon every two weeks. No smoke, no problems with the oil, and no bubbles.
If the cap were bad, it would go into the overflow tank. Where are you losing it from? If it's the overflow tank, make sure that's not leaking too.
My only other idea is a bad heater core. Can you smell antifreeze in the cabin when you turn the heater on? If so, you have a bad heater core.

 

Can't smell any anit-freeze in the car and the carpet is not wet. The head was just rebuilt and checked for everything and it was fine. I can't tell where I am losing the coolant. Maybe from overflow and it's just not doing it at idle. I let it idle for over an hour and there was no coolant loss and no coolant on the ground. I'm going to have the system pressure checked today.

 

Let us know how you come out!!