A cold-blooded engine struggles to idle, stalls easily, or hesitates under throttle when first started. The condition is typical of older carbureted vehicles without automatic chokes, but can also indicate vacuum leaks or faulty temperature sensors in fuel-injected engines. Mechanics use this term to describe a car that needs coaxing or a long warm-up period before it can be driven smoothly.
Heard on the job
Give it a few minutes before you pull out, she's a bit cold-blooded and will stall if you just dump the clutch.
Insider tip
Fuel-injected engines should not be cold-blooded. If a fuel-injected car hesitates when cold, check the coolant temperature sensor or idle air control valve.