No guessing and no generic checklists — answers scoped to your car.
Causes ordered by how common they are on your generation, not the whole model range.
What to inspect first, so you confirm the cause before you spend a penny.
Exact part numbers alongside each cause, ready to drop into a plan.
IMS and bore scoring on a 987.1, AOS and plastic coolant pipes on a 981 — the causes and their odds shift with your engine and year.
Once you’ve found it, push the parts and steps into a service plan, then tick it off and log it to your history when the work is done.