My wife's 2014 Prius V has the cold start knock for a few seconds. My local mechanic is great for most things, but has never done a Prius head gasket. Looking for a non-dealer recommendation in Boston area. Help!
Maybe get some opinions and some things like that and you're in a cold area and barking up a tree that you may not want to attempt to climb maybe I don't know I certainly wouldn't. Or couldn't bring myself to do so knowing what I know now not an option we'll be costly You may not get the money back out of the vehicle at all.
What’s the miles on it? To avoid another blown head gasket, be sure to get the EGR system, including EGR passages in the intake manifold, thoroughly cleaned. See first two links in my signature (on a phone turn it landscape to see signature). With the EGR cleaning , there’s precious few professionals doing a decent job. Dealership service departments are clueless, will tell you it’s not needed, won’t “stoop” to cleaning, just replace parts (at least a grand for parts, before labour). DIY cleaning costs next to nothing, takes a day or two, or ask your regular mechanic to take it on; it’s not too involved.
It is no different than any other Internal Combustion Engine. Are you certain it's a head gasket? What is the mileage? Is the coolant tank low? Have you had a pressure test? Quick changes in temps could cause moisture to form in the intake manifold which will also cause some knocking. And shutting the engine off before it's warmed up on a cold start can cause it the next time it's started sometimes.
Yeah consider leak-down test, or boroscope inspection of combustion chambers, preferably with coolant system pressurized, to accelerate coolant leakage into cylinder (the usual failure mode).