I have a 2014 Prius with the death rattle. I have no loss of coolant and I have cleaned out the intake manifold and also the Erg valve. It rattles only when it’s from a cold start. If I accelerate before it runs a cycle it won’t do the death rattle. Every once in a while it will hesitate when turning a corner. Had a mechanic look it over and he said he didn’t see anything wrong with the coolant and I should replace the upstream O2 sensor. After cleaning out the IM the check engine light has not been back on. I have also put some fuel injector cleaning through it. Any thoughts on what to do next?
how many miles on her? did you carefully clean the 4 little ports in the IM? what does 'before it runs a cycle' mean?
219000 on it. I clean out the little holes on the manifold with brake cleaner and small wire brush. I clean it out about 2 weeks ago now. when you first turn on the Prius and you hear it start up and it runs for about 15 seconds is what I refer to it running a cycle. The code was p301 I believe
Between the miles, late-in-the-day cleaning and code, it’s very likely the head gasket. No coolant loss is one plus, maybe just starting. Leak-down test and/or boroscope inspection to be conclusive. See the critic thread link in my signature.
15 seconds? My engine runs very nearly exactly one minute before stopping, regardless of ambient temperature, if the wheels aren't turning. When exactly do you hear the "death rattle"? Immediately as soon as it starts? Not immediately, but during the 15-second (1 minute?) run period?
Once I turn the car on and it’s been about 5 to 10 seconds I hear the engine turn on and that’s when I get the death rattle.(the high pitch sound it makes before it actually runs) The rattle has lasted anywhere from 10 to 20 seconds. If I go ahead and give it gas before the engine starts running it doesn’t rattle but I can feel/hear the misfire.
