Originally Posted by isaiah990 (Post 3286102)

I have a 2013 FR-S, right side of engine near cylinder 4 engine shakes and rattles ECU is throwing P0354 and P0304
Engine is also making a weird noise near the right side of engine
-I've replaced ignition coils and spark plugs on cylinder 4 with no luck, any ideas what it could be?
I've noticed the coil pack does not sit completely flush when plugged on, is it supposed to sit tight and flush against the engine/spark plug?

Originally Posted by humfrz (Post 3286106)

Hello isaiah990 and welcome to our forum - :clap:

Happy holidays!

So, your car is acting up. Do you have any power mods?

You replaced the #4 plug and coil.

I reckon the coil should fit snug onto the spark plug. Is it fitting differently than the other coils? You might try swapping a couple of the coils to see if the engine code changes.

After that, I'd suggest you disconnect the battery for a spell, hook it back up and see if any codes come back.

The next easiest thing to check would be to check for a vacuum leak.

I hope you get it sorted out.


humfrz

Originally Posted by JD001 (Post 3286108)

You feeling okay? I thought diesels sound like that.. get a petrol if wanting something a bit more civilized..

Happy holiday.. BTW, I bet the sand helped with the digestion.... A bit of grit is good for the gut...

Originally Posted by isaiah990 (Post 3286446)

The noise seems to come in low idle after about 15 seconds of my car warming up

Originally Posted by tomm.brz (Post 3286447)

after 15 more or less seconds the only things that can change are:
-direct injectors goes on and port injector goes off
-oil circulates into the AVCS and activates it

Originally Posted by tomm.brz (Post 3286447)

after 15 more or less seconds the only things that can change are:
-direct injectors goes on and port injector goes off
-oil circulates into the AVCS and activates it

Originally Posted by isaiah990 (Post 3286450)

Thanks for your reply, I was thinking it could be the injectors, would that cause a code p0354 or somehow affect the coil pack? I’ve unplugged the cylinder 4 coil pack ignition D while the car was running but it did not change anything so I’m not sure if it’s the coil pack or injectors causing it. I’m trying to get this fixed asap hopefully before New Years but I’m having trouble diagnosing the problem

Originally Posted by Stomachbuzz (Post 3286483)

I disagree. As far as I know, there are several events that take place when a motor is cold that change/stop happening later on.

As you said, at some point, the injection method switches, and the 'crickets' can be heard.
Not sure about the AVCS as I'm not familiar with that.

Modern cars also have a secondary air injection (kinda sounds like a jet engine, but not as loud unless your air pump is going bad) for about ~90 seconds when a car is cold.
There are a few other processes that change as well, and you can clearly hear the idle change sound and speed throughout the process.



Yes, I can hear the miss. This type of engine should not have an idle that is so choppy.
I am also concerned about that metal rapping sound. It's an accessory, I'm sure, but still distracting in the video. These types of sounds never show up well in video recordings.

The why you start diagnosis with ignition problems is to start switching the coils around.

Computer says cyl#4 misfire?
Swap cyl#1 ignition coil with cyl#4 ignition coil and see if the code follows over to cyl#1 or stays at #4.

Obviously, this is assuming that the coils are properly installed, and there isn't a glaring issue such as debris in the spark plug hole (maybe why your ign coil isn't seating properly?) or other.

Originally Posted by isaiah990 (Post 3286493)

The metal rapping sound is what I’m trying to figure out, I thought it was part of the misfire
-I’ve swapped coil packs and the misfire remains on cylinder 4
-cylinder misfire occurs constantly after 15 seconds when idle rpm drops on cold start
-When I unplug coil pack #4 right after I start the car it causes it to stall. When I unplug the same coil pack after the misfire occurs or 15 seconds after start it has no effect on the idle
Could this noise be a failing injector?

Originally Posted by Stomachbuzz (Post 3286502)

Just watched the 2nd video.
You definitely got at least 2 issues going on there.

Motor is missing pretty bad, and then there's that metal sound.
Metal rapping sound is far too slow to be from the engine internals.

Almost sounds like you have a nasty exhaust leak as well.

Why are you putting your hand down into the bottom of the engine bay in the video?

Originally Posted by isaiah990 (Post 3286503)

I’m not sure what the metal rapping noise is from as it comes on at the same time it begins to misfire. And I cropped the video, I was unplugging the coil pack to see if it it had an effect or not
-Sheesh now an exhaust leak, I’ll have to check that out. What noise is the exhaust leak making?