Bubbling in main radiator hose and coolant reservoir overflowing?

Hi,

Thanks for the reply. Well, I hope that's not the case but yeah, it's a very real possibility. So far, the engine has passed a few of these tests. I did the chemical test and detected no exhaust gas. The liquid maintained its dark blue color. The engine oil is a little on the dirty side but still very clear and not milky. I took off the oil cap and there was no mayonnaise like substance on the bottom. Also, no signs of oil in the coolant. While running the engine with the radiator cap off, I used a funnel to hold some of the expanding coolant. There were some bubbles for about 5 minutes then the bubbles stopped, and the coolant quickly rushed back in the radiator. After that no more bubbles appeared. I hope that I just had excess air in the system after replacing the thermostat. I also put my old radiator cap back on and drove the car around. The overflow reservoir is not getting excessively high like it was with the new cap. Although my reservoir tank keeps dipping below the cold fill line. So, I don't know, still leaking I suppose. But it's much better than it was before I replaced the thermostat and housing. I may need to take it to a pro for the other tests listed in the video. If it is a head gasket, is this something I could do? I know it's a big procedure.

Update: I did a radiator pressure test today. It held 12 psi pretty strong for about 5 minutes, then took about 15 minutes to drop 1 psi. I heard lots of different opinions on how long my system should hold steady pressure so curious to see what others have to say about the results.

Unfortunately, I couldn't find any external leaks off the bat. The test was done stone cold. But I wasn't able to see the radiator housing leak until I started replacing the thermostat. So, I'll do another test today and see if I can find anything. Thanks for the link, very helpful. Curious to check out the weep hole and freezer plugs. How long should your system stay pressurized before there's some drop in psi? I got to imagine every system has some loss so wondering what the threshold is.

It is just nuts and bolts! I like that. Hopefully it doesn't come to disassembling my engine but appreciate the offer for help.

One last question, are there instances where an exhaust gas test of the cooling system will still pass (liquid stays blue) but there's still a blown head gasket?

I found my other leak, well found where it's dripping at least. Is pooling up around the edge of my oil pan. I'm assuming it's not coming from the oil pan itself. Hopefully. I'll investigate a bit more this evening, but it's a start. Maybe it's coming from the water pump? That's my first guess at least. Attached a picture.

Looks like the leak may be coming from the water pump. Took a video, it zooms in on the potential leak at the end of the video. It has a green stain around the gasket. As a side problem, it seems like there's more oil than there should be as well near and around the oil pan area. Also added an image of this.

Thanks Ken.

I may take my truck in to confirm if the head gasket is blown before I do anything else. I hope the air is getting in through the leak, I've heard that's possible since when the liquid escapes, that volume has to displaced with something. But, we'll see. I may just sell the truck for parts if the gasket is blown. Appreciate the help.