Noises

I’m a first time driver. I got my first car, an Acura 99 TL about 8 months ago with 155k miles. I have driven it for about 9k miles now.

There was oil under the valve cover so I decided to change the gasket myself. I did spark plugs about 4 months ago (my first ever job!) so that gave me confidence.

Ever since the gasket replacement, I’ve had problems 🙁

On the bright side, the RPM settled on idle from 1000 to 800 and gas economy has improved so I thought I did a good job. I used your video for a EGR flow correction. That helped a lot 🙂

There we’re no strange noises after I did the gasket except for a constant, low ticking (I don’t know if this was present before). I just changed the oil twice with 3 weeks gap after the gasket replacement and the sounds have reduced somewhat but not fully.
The radiator started to lose fluid after the gasket repair, too! I could notice steam from the hood occassionally. Since I would only lose very little fluid overnight, I just put in some sealant. Did that in 6 or 7 steps using a small bottle before emptying it. There is no low fluid level now but after that sealant, I notice the reservoir gets full now. I have checked hoses from radiator to reservoir and they seem to be okay.

Moreover, there is a strange knocking or burping sound coming occasionally while idle (probably the engine?) At times, on idle, the car kind of wants to shut down but doesn’t. Kinda loses power for a second. I have had occasional white smoke coming from exhaust in winters (I live in North of Florida) mostly from a cold engine. The car does not overheat. The engine oil level is okay and not milky. What could be going wrong?

Edit: I recall the knocking type sound came after I used a syringe to take coolant out from the reservoir to put it in the radiator. My bad?