When in the year do owners report it?

NHTSA owner complaints about this part run furthest above the usual seasonal share in April: about 61% more of them name an incident that month than complaints about any part would predict. A complaint is a report, not a measured failure.

Complaints by month of the incident, against all complaints

What it shows: April is the largest at 12% (all: 8%), followed by January at 10% (all: 9%); the smallest shown is March at 5% (all: 8%).

Source: NHTSA owner complaint files · file downloaded 2026-10-05

Data and chart by CalcScrape: Valve Cover Gasket Replacement