Cylinder misfires...at my wit's

How many miles on your car?

Do the misfires only occur after a cold startup, or do they occur all the time?

Is the engine coolant low?

 

Head gasket, how many miles on her?

 

Yeah while you had the plugs out you can rent or borrow the borescope at the auto parts store. And then look at least in one and two cylinders and have the thing looking back up and you will see the droplets That's generally the deal or it's remotely possible you got crappy coils that's really stretching things but in the current trend of manufacturing it is highly possible so something to look at they're not easily checked I don't think with an electrical tester so there's always that I had the same problem on a generation 3 and the coils that I had in the vehicle were working on another engine not 20 minutes prior maybe a couple hours prior and then put on my persona and they worked for a 2 hours and then the next time we started the car missing and carrying on all over the place We see nothing going on in the water department in the cylinders or any of that I changed the coils and it cleaned all the misfires up but the rattle still there Not as bad and not as often but unusable still.

 

EGR cleaning should ideally be done every 50k, or if you’re feeling lucky, delay first cleaning to 100k. Like coolant change interval.

I’d concentrate on head gasket diagnostics now.

 

Same problem.

 

Leak down test before throwing parts at it is the rule.

 

That's the one set up I don't have here is an old snap-on or matco leak down testing kit with the air fitting for the spark plug hole and all that kind of like a compression tester which I do have the nice snap-on one I guess I could make a rig but as smooth as the engines running in my case I don't think I'm doing much leaking down when this rattling is going on it just doesn't seem like it's in the motor something is definitely seemingly rotating and not in balance if you will but it's not creating that miss that you get when the fire's getting put out. Matter of fact other people have come and looked at the car and made the same comment.

 

But you need to rule water droplets out and not being seen in the spark plug hole up against the head and block connection.

 

Does it go away after a minute or two or is it constant?

Does it go away at higher speeds?

Any small loss of coolant?

How long has this happened at cold start, even occasionally?

A sticking open egr valve can cause issues at low speeds. The Car Car Nut has an egr video where he blocks egr flow to rule this out.