[Chryxtivn]

Hi, so my X3 had an "small" issue when I start up, the engine kinda sputters for a bit and go back to normal. This happens occasionally and this happened before I changed the spark plugs.

So, I took a risk and tried to replace it myself using the Bosch brand spark plugs for the first time from Autozone. It was a pain in the a** to replace it all on the N55 engine, especially the last 2 in the back of the engine.

Started it up and it runs but its sputtering even more and shakes a hell lot more than before. I do have a BIMMERCODE reader but the dashboard isn't putting out any check engine light at all.

I'm in Madison, WI, and I contacted all the autoshop that specializes BMWs and they all have a week delay availability or more. The thing is this X3 is my daily and I gotta get it back on the road as soon as possible. My X3 got about 105,000 miles on it. Any help/tips would be greatly appreciated!

[mwat]

Are you sure you used the correct bosch plug? Did you use a socket with a swivel on it to do the job? Did you torque the plugs to spec or guess?

How are the ignition coils? Have they ever been replaced? If so, which ones?

You're right, the 6th plug is awful to get to. 5th wasn't so so bad.

[Chryxtivn]

I told the guy at autozone the model and brand of my car, he looked it up to match the right spark plugs for it. I also compared the old and new next to each other. They seem to match.

I used a socket w/ swivels to replace the spark plugs. So, yes i guessed the torque.

The coils are fine, no damages or anything like that. They seem to look like new.

[Wgosma]

Do the BimmerCode scan, you may well find fault codes- go from there.

[E36M3]

As thin as the ceramic is on these plugs guessing at the low torque value can often lead to cracked ceramic on the plugs and then they misfire - ask me how I know….

Many of us have made the mistake you just did.

It’s time to pull out the plugs you just installed and carefully examine them as the cracks are often well hidden. When looking for them the first time I did this it’s easy to miss.

[Chryxtivn]

Originally Posted by E36M3

As thin as the ceramic is on these plugs guessing at the low torque value can often lead to cracked ceramic on the plugs and then they misfire - ask me how I know….

Many of us have made the mistake you just did.

It’s time to pull out the plugs you just installed and carefully examine them as the cracks are often well hidden. When looking for them the first time I did this it’s easy to miss.

The code went up, misfire on cylinder 3. Seems its repeating the code to only to the third cylinder. I took it out and checked the 3rd spark plugs, it seems fine and unbroken? I probably miss it, but I'm feeling that its not damaged.

[Wgosma]

Originally Posted by Chryxtivn

The code went up, misfire on cylinder 3. Seems its repeating the code to only to the third cylinder. I took it out and checked the 3rd spark plugs, it seems fine and unbroken? I probably miss it, but I'm feeling that its not damaged.

Swap the coil pack from cyl #3 with another cylinder....see if the misfire follows the coil pack to it's new location, if so then you have your misfire cause as the coil; If not, then you may have a plug or fuel injector issue at #3.

[mwat]

Originally Posted by Chryxtivn

The code went up, misfire on cylinder 3. Seems its repeating the code to only to the third cylinder. I took it out and checked the 3rd spark plugs, it seems fine and unbroken? I probably miss it, but I'm feeling that its not damaged.

Lucky you cyl 3 is easy to get to!
Do what the other person said, swap the coil first if it follows then it's the coil. Otherwise swap the plug, if follows etc etc

I'm guessing it's probably not an injector but stranger things

Sometimes I've heard of plugs just being bad out of the box, it could be something simple like that as well.