1998 Ford Explorer Sport V6 2WD- Radiator Problem

About a month ago I had a leaking radiator replaced in my SUV (233,000+ miles). Shortly after, my temperature gauge ran hot. Checked reservoir and it was full, checked radiator and it was bone dry. The mechanic said the timing gasket cover needed replacing and caused radiator to leak. To add to matters the check engine light was on. I asked if this problem could be causing check engine light to be on. Technician was interrupted by co-worker that noticed white smoke coming from tail pipe (it was morning and the car ride over was about 10 minutes). The Technician then said he believed my head gasket was going. Went to different repair shop for second opinion - on drive over car producing mounds of white smoke - white smoke disappeared on arrival to shop. Mechanic said head gasket looked good and I needed plenium gaskets replaced and this is what caused the car to run lean which caused the codes for check engine light, also I needed oxygen sensors replaced. Gaskets were replaced and mechanic determined oxygen sensors could be cleaned since they had been replaced about 8 months earlier. Mechanic repaired, checked and tested car but white smoke did not appear for him. He said car should be fine. Next few days car still has strong radiator scent and although I don’t see mounds of white smoke, there is a noticeable amount of white smoke in the mornings and if car sits for an hour or so. Returned to last mechanic twice and they say everything looks fine, but they can’t explain why the radiator smell is still present. They believe radiator fluid was spilled inside engine and is burning off - it is true fluid was spilled because after the car overheated I added fluid (after the radiator was completely cool) and dripped a bit. I was told to look for a “sweet” smell from the tail pipe in the mornings (which is hard to decipher) and if I continue to see white smoke to bring it back to the shop. Does anyone have any idea what might be going on?