I may have unmasked a possible head gasket failure or cylinder wall crack. I’m not sure | SwedeSpeed

So it all started when I bought this 2011 c30 T5 169k for $700, the lady said the transmission was bad. It was the lower return line so I replaced and refilled and it drove and shifted great. After that I replaced the oil filter housing/pcv which I’m guessing was still original. I also replaced the cracked coolant reservoir which had a slow leak that I could hear when it was hot. Well I started getting a misfire on cyl 2 so I did plugs and replaced the coil pack. I also put on the missing exhaust manifold bolts and it was running a lot quieter and smooth. For a little while it was running good with an odd occasional weird misfire sound at startup both warm and cold, it was completely random.

After a little more road testing I discovered a leak over by the thermostat housing so o ordered the upper main and lower radiator hoses along with the thermostat. I noticed a crack on the pipe at the plastic intersection part on the upper hose so I’m guessing that is where the coolant leak was coming from. I filled it up with coolant as much as I could get then started the engine and let it idle with the cap off until it was just about centered on the temp gauge. It was blowing warm air too. It seemed full and wouldn’t take any more so I took the extra coolant with me and made a trip to the gas station to fill it up. It ran great the whole way to the gas station, I shut it off filled it up and restarted.

When I restarted the car a big white cloud came out the exhaust and it was misfiring struggling to stay running and the check engine light started flashing. Great. I was able to make it home and when ran above 3k it seemed to feel smoother but I could feel it want to choke out when the rpm’s were low. Now the smoke smell didn’t smell sweet and it was only when I started it after the engine was warm, cold starts were no issue before all this. When I got home I checked the coolant level and waited about 5-10 min to recreate the situation. The same thing happened, big white cloud when I restarted it with a burning type of smell.

I plugged in Vida and got this

The same codes I was getting after I replaced the reservoir. After that I called it a day. I went out this morning and checked the coolant level, it is still the same and I restarted it out of curiosity and I got a big cloud of white smoke.

My fear is that all of these coolant leaks were keeping the pressure down and masking a blown head gasket and after I fixed all of the leaks it finally popped or it’s been there the whole time but I just didn’t know it. I haven’t ran any compression or leak down tests or even the block tester to see if combustion gases are getting in the coolant. I’m not really sure if it’s anything else that could cause this but I’m thinking it’s a head gasket and hoping it’s not a cracked cyl wall.

any input is appreciated.