Sounds like your first mechanic charged you for some unnecessary work. Coolant change, engine cleaning, how is that relevant. Or they probably didn’t do anything at all and just reset the check engine light. It takes a few days for it to come back on after a reset.

Anonymous wrote:Explain to your (new) mechanic what you told us here so he would know it's not an isolated issue.

Great suggestion and I almost forgot. Thank you. Took to a shop and they seemed to have found the problem. Fingers crossed. $350 repair estimate.