Changed Spark Plugs and now a puffing sound
 

I am posting this thread for MIKE MikeInd. He dose not have internet access at home so I am posting this question for him.

He Changed his spark plugs on the passenger side of the engine. He used Denso Iridium plugs. He only changed the 3 on the passenger side for now, He will be changing the other side tomorrow.

After he changed the plugs, he started to hear a puffing noise that sounds like it is internal, He only noticed this noise after he changed the plugs. The only way he could explain the noise is that it sound ed like a puff..puff..puff. He wanted me to post and see if any one knew what the problem or noise could be. He will be looking at this thread tomorrow when he has access to the internet.

I would change all 6 of them before he tries to figure out what is going on. It could make a difference. If it still is puffing after he gets the others changed, then we can try to figure it out. I don't know what would be doing that. Maybe someone else has heard of this. Hope the other plugs fixes the problem. :)

Maybe now he got big old gaps on one side and new tight gaps on the other.:)

I haven't personally seen a spark plug fail in many years (Champion plugs in small block Chevy's circa 1975), but if the ceramic core was cracked, that "might" produce such a sound. This is only a suggestion since I have no idea what a modern, or especially Subaru, engine would sound like with a catastrophically failed plug. One immediate clue is the rough running off course.

Only time I ever heard of a "puff puff" sound associated with plugs is when plug worked loose and compression was leaking out around or through it. Is it possible he may not have properly installed one of the new ones?

Johnny

I don't know Mike's level of expertise, but I suspect an exhaust leak. I know he said it didn't make the noise before, but how closely did he listen to it before he replaced the plugs?

But, as Earl suggested, I'd replace all six before trying to diagnose it.

What prompted the plug change? The OEM NGKs are good for 100k miles. I had mine in for 133k and they were nearly new when I took them out. :)

I would STOP driving it if he still is and recheck the plugs to make sure he tighned all of them. If this is the problem he will be lucky if he didn't destroy a coil pack by now.:eek: The next question is: Does it also skip now?

Hey, I did not notice it before..because I was not looking for it. Just like you thought.

I will do the other 3 this weekend.

I changed them because the engine has a rough idle and I did not know when they had been done last..I have only had the car about 2 months max. It has 170k on it.

No, they are dark in color. looked old.

I put in Nipp Iriniums.....if that is how you spell it...lol

Yes, to prevent from cross threading...i screwed in by hand...then used a wrench....then a torque wrench...to specs.

It soonds like a internal puff...but I will change the other 3 ...then listen....


That is what I though happened..a coil....but I herd if that happens the engine will shake BADLY...mine does not really shake at all.

I did get the code for a egr valve...but the dealership says it is the solinoid beside the egr valve