Hey guys, I need a little help here...

Yesterday, I changed out my stock spark plugs on my 04 Touring Z. I bought it used, and it currently has 38,500 miles. Here's problem, the car runs horribly now. It sounds like a lawn mower and is idling really rough. The plugs were replaced one at a time, so there was no way of crossing any wires. We (my dad and I) did disconnect 2 hoses, but those were both put back into place and secured. So, any suggestions on what the problem may be? I need this fixed asap b/c I'm taking a 1000 mile road trip tomorrow morning.... Ugh. (Oh yeah, found oil in cylinder 6, awesome)

edit- swapped plugs for NGK Iridium LFR5AIX-11

 

Did you gap the plugs? Did you torque them to the right ft/lbs? If you found oil in the cylinder then you might have to replace the O-rings and the head gasket seal just to be safe. And make sure you didn't cross thread the spark plug. (Next time use anti-seize) Check out the DIY thread its pretty informative.

 

Thanks for the reply. Didn't gap the plugs since they're iridium. While researching the site, I read about replacing the valve cover so I figured I'd look into that since its only in cylinder 6. Didn't cross thread the spark plugs and used anti-seize, so I'm scratching head lol. I actually just finished tearing down the car again and rechecked making sure that everything was secure and it was... The car still sounds pretty loud.

 

What do you mean by loud? Does it sound like air is coming out of the coils? Check the old plugs maybe the old gasket stayed in the hole. If you didn't cross thread, and you have no blow by from the spark plug holes (maybe caused by extra gasket), then start looking electrical.

 

If your Z was running fine before the spark plugs were changed then it has to be the torque settings. Do what turboboy said. Maybe the old gasket is in there still. Is it possible to post a vid to describe the "loudness"?

 

I don't have an answer for you but I just wanted to say that I just changed my spark plugs and I am having the exact same problem. I also found oil in the cylinder but mine was in cylinder 5. If you get any type of answers through PM could you please let me know. I was also looking at other forums and it was saying that maybe there was a shorted coil pack.

 

Actually I the same problem. Ever since I swapped my plugs the engine light keeps coming back. Does the torque really matter or we just tighten it up so its on tight? I dont have the loud noise though. Does the sound of the car sound like a subaru boxer engine? Lol. If it does you probably plugged the plug into the wrong connector. I also swapped out all 4 of my sensors at the cat converter. My friend who is a tech says that might be the problem but the light came back. So Im going to ask him to torque it if thats really needed. -_-

 

The car did the same thing after plugs changed. But my car has a misfire now, it actually is dropping a cylinder. So the sound like a Subaru is probably just that, mine throws code P0300. I have checked the plugs and everything's fine. So I am now going after the coilpacks or injectors.
I wouldn't say, mine started doing it right after, so my problem could be different, but fairly close.

 

My diagnostics check showed up as the DTC420 or 430, which the possible cause can be spark plug or fuel injector which Im thinking was the spark plugs since the car was working fine before changing the spark plugs. If Im changing it to bosch platinum 4 prongs you think theres a special way to do it or should I just stick with the stock ngk and try to do the gap and torque? Do you have a engine light popping up on your car?

 

is anyone checking the gap?


If car runs like crap after. Swap back in the old ones and see if it still runs like crap. If not its the sparks and a error during install.

If it still run likes crap, more troubleshooting to do...

 

Im guessing your talking about the gap at the tip of the spark plug.

 

So I fixed my problem. Get ready for this..... I over tightened the strut tower bar which caused it to rest on the engine creating my "rough idle" lol
(insert face palm pic here). Ugh I'm so embarrassed, at least I installed everything else right lol

 

How do I get rid of my SES light. Lol. This is lame.

 

Well, at least it was something simple.

 

You dont gap the iridium plugs, BUT the gap can be off from the factory. Always take a few seconds to check it before installation. It will save you tons of time for pulling them back out again.

If the gap is off, get another one. The tip of the iridium plug is very easy to break, once it breaks, no more warranty.

 

Okays. Well I bought my car to the Nissan dealer and got a check with a code of P2A00. Which is A/F Sensor 1 Bank 1 Circuit Range/Performance. According to their little diagnostics it says my car is running lean and the voltage while idle is low. Im guessing I have to do something with my fuel injector to even it out. -_-