Hi. Big fan of this forum so I thought I’d throw this theory out there. I had the head gasket changed by Tampa Hybrids as I was experiencing the rattling about a year ago. So far so good. I noticed a slight smell of antifreeze so not taking chances…before the head gasket ruined the motor. (Also changed ignition coils at that time) 2010 has 260,000 mi but otherwise running great now.. On to a few weeks ago… The last couple months the rattle occurred 2x on cold start. Put some acceleration to it and went away quickly. As a former mechanic I have a question about a theory that one of my injectors is dribbling raw fuel into a cyl temporarily fouling a plug for a few seconds… Anyone hear of this? I might add my mileage dropped a few mpg during that time. Do the injectors wear out and cause this sort of thing?
Or water droplets that collect in the EGR. I've noticed such droplets, taking off the EGR pipe (between EGR valve and intake manifold). I did get a cold-start shake once, after the engine had just run a few seconds, the previous day.
You live in Florida, a high humidity climate. It's more likely @bisco & @Mendel Leisk are correct, a few rough startup after high humidity days are one-offs IMHO. If the issue becomes more chronic, then you probably have issues. Dump some concentrated injector cleaner in your tank, on your next fill up - to nip the possible leaky injector issue - which I doubt... More likely you just got some bad fuel. You fix that by fueling up at high traffic gas stations. Fuel doesn't just sit around and has a lower likely-hood of getting contaminated. Hope this helps.....
And if you're sitting in the car and no this is going to happen you can immediately be giving it the gas and this would not happen correct You get off idle and the rattling is immediately gone?
If you know its going to be really cold the next day, try taking off the coolant reservoir cap briefly to release pressure then put it back in. It should help with the rattles.
Did Tampa Hybrids also clean the EGR system, say in the course of the head gasket replacement? I'd suspect they did; they're on the ball.
