1995 Honda Del Sol Si D16z6. I had to replace the head gasket ( and also new intake manifold gasket ). The car sat a couple of months before getting it all put back together. After reassembly, it starts and runs fine. But at a cold startup there is a random spitting sound coming from under the hood every few seconds until it warms up a bit then goes away. It didn't do this prior to the repairs. I would like to add that the head gasket had been replaced by a mechanic in January of 2025. It failed again in December 2025, less than a year after replacement. After the head gasket failed again, I decided to do the job myself because of the circumstances upon which the gasket failed again. About two months before the head gasket failed again, I began seeing a black sticky substance in the coolant reservoir. At first I thought it was oil but it was more of a sticky, gooey substance. Then I could see it floating in the radiator. So when I tore the head back off, the head bolts were overtightened. Guessing around 100 ft. lbs.. of torque on them. So from this I assumed the black sticky substance floating through the coolant was silicone from the smashed head gasket. After repairing, I flushed the cooling system best I could. But I'm wondering now if the random spitting or popping sound is coming from either the IACV or Thermal Control Valve as the silicon may have gotten into one or both of them, due to coolant flowing through them, causing them not to function properly. Any thoughts, suggestions, or ideas about this?