Wandering Coolant Leak

bobsquatch

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I thought a new thread might be appropriate here. My engine cooling fan gave out a while ago on my 2005 LS V8. I was repeatedly bleeding the cooling system thinking I had trapped air causing the overheating. I was not driving the car, just repeating the air bleed procedure shutting it down as the gauge read over temperature resulting in boiling over when the engine was turned off. Finally I realized after 3-4 frustrating attempts that the cooling fan wasn't working. I replaced it with a used fan and everything works perfectly. Now, likely due to overheating I have a wandering coolant leak. After properly bleeding the system, there are no leaks while running/ warm. After shutdown still no leaks for 10-20 minutes then at the front of the engine. This leak will persist until the degas bottle is empty overnight. If I restart the engine after the leak has begun it will cease but now the system has air in it resulting in coolant leaking from the degas bottle area soon after shutdown, likely from excessive gassing. I can watch it fill quickly after engine shutdown. I can't see where the leaks are actually coming from so I ordered a bore scope camera to get a better look. I am wondering if it might be the intake manifold as you have to drain the coolant to remove that or any other common leak point. I have replaced all cooling system plastic parts except the radiator and the one that required removing the intake manifold with factory parts. I think I have the last piece laying around my garage somewhere so I guess I'll start there once my bore scope arrives tomorrow. Any thoughts on where else to look are appreciated.
 
Thanks Joe, I'm reviewing the stickies for what I may have missed. I think just the radiator and gooseneck are left. I got the rest when I did the degas bottle, DCCV, belts and hoses thermostat, etc... all OEM. I got it pretty hot bleeding the system but not under load driving so I don't think I did any structural damage. Heads, head gasket and block should be ok but you never know. The engine bay is so tight and my eyes aren't what they used to be. I think the bore scope camera is going to help me a lot. As always, thank you for your insight. You have helped me a lot over the years.
 
Thanks Sport, I got my bore scope so I think I can track it down. Looks like the water pump, but It's a little nose down and I want to confirm that's it. Engine is hot and I am letting it cool some as the camera gets hot to the touch pretty quickly and I don't want to cook it. I also want to thank you for all the help. You guys are an awesome wealth of knowledge and experience. By the way, I have discovered a 16oz water bottle fits over the 3.9L heater bleed nicely making it easier to see a steady stream and to capture it avoiding the mess.
 

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