Merkfan, Welcome.I’d like you to see pic and possibly share your thoughts. All of a sudden dropped down to 60 then 40 and then back to 86. Once coolant temperature start oscillating engine rev change and here yellow check engine came on, first time. What can it be? View attachment 2638391
Please update your user CP info....
click on your icon----> click on Account Settings---->
goto Account Details----> add vehicle details---->
ADD your make model YEAR ----> click save
Readers/members have no idea what you are driving.