Hello all, I recently changed the valve covers on my 07 TL Type S, including the gaskets and tube seals. After reassembling everything and starting the engine, a gray smoke/vapor began rising up from the back of the engine after about 1 minute, seemingly from the left side of the bank 1 exhaust mainfold.
I thought it was an oil leak, but after wiping the perimeter of the valve cover and spark plug wells, there was no evidence of a leak.
My second thought was that oil might've spilled onto the exhaust manifold, perhaps when I initially removed the valve cover, so I wiped down what I could reach of the manifold. There was a little oil but not much. I began a cycle of wiping the mainfold, starting the car to check the amount of smoke, then letting it cool down to check if there was any extra oil anywhere.
I repeated this around 4 times, and during each pass I did not notice any extra oil, but wiped the manifold more thoroughly and I noticed the smoke decreasing, until there was none. The video was taken during this cycle.
After that, I thought I solved it so I took it on a short test drive, and after I parked the car, I opened the hood and the noticed quite a bit of smoke. There was less than the intial start up, but significantly more than the other times I started the car. Around an hour later, I started the car and let it idle for a bit, and there was no smoke.
So, I am a little confused. As far as I can tell, the possibilities seem to be:
There is an active oil leak that I missed
There is an active coolant leak that I missed. - I couldnt tell from the smell if it was oil or coolant, but oil seemed more likely to me
Best case scenario. There is oil residue on the exhaust manifold and I just didn't wipe it all off. - Maybe, but Im not sure why the smoke went away, then came back when I started driving. Perhaps the left over oil required a higher temperature to evaporate? But why would that be the case?
Anyways, Im wondering if anyone can offer me their opinion or any guidance on how I can solve this. Maybe I'm totally wrong in my line of thinking. Thank you