Misfire is back............!!!!

[Ultrastar]

sigh.......

ok let me give you little story on my LS
I purchased my 2002 v6 LS back in december with 200000KM on it, had misfire cyl 1 & 6 upon purchase (ran the codes before buying).

so I bought a set of visteon coils on ebay & NGK iridium plugs (160$ + 60$)
about 2 weeks ago i installed all 6 coils and plugs and did an oil change, replaced air filter at the garage (all that cost me 170$).

Erased the codes myself and afterwards the LS ran LIKE A DREAM
i was so happy with the newfound power i was flooring it whenever i had the chance

anyhow, about a week ago, CEL returns:

p0300 (random/multiple misfire)
p0304 (misfire cylinder 4)
p0305 ""
p0306 ""

I had no symptoms at all, so I cleared the codes just to see how things would turn out.

During last week, the engine would sometimes sputter on startup for the first few mins, and the car would shake a little, these were the only symptoms.

So yesterday, the goddamn CEL light returned:
p0305
p0306

what could be causing this?
the engine sputter and shaking on startup are my only noticeable symptoms.

more info:
when i changed the plugs i did noticed some oil on the old spark plugs, the old boots looked somewhat dry though

also, in the following pic (not my car):

the circled part was cut off from the intake tube (?), the guy at the garage simply taped it up with electric tape as a patch for now (said that would be fine...)

any ideas guys?
hopefully its not the gaskets : (

 

[G-RELL]

What do you mean by somewhat dry?

 

[dnce0589]

Replace your valve cover gasket same problem im having

 

[stockls]

sigh.......

ok let me give you little story on my LS
I purchased my 2002 v6 LS back in december with 200000KM on it, had misfire cyl 1 & 6 upon purchase (ran the codes before buying).

so I bought a set of visteon coils on ebay & NGK iridium plugs (160$ + 60$)
about 2 weeks ago i installed all 6 coils and plugs and did an oil change, replaced air filter at the garage (all that cost me 170$).

Erased the codes myself and afterwards the LS ran LIKE A DREAM
i was so happy with the newfound power i was flooring it whenever i had the chance

anyhow, about a week ago, CEL returns:

p0300 (random/multiple misfire)
p0304 (misfire cylinder 4)
p0305 ""
p0306 ""

I had no symptoms at all, so I cleared the codes just to see how things would turn out.

During last week, the engine would sometimes sputter on startup for the first few mins, and the car would shake a little, these were the only symptoms.

So yesterday, the goddamn CEL light returned:
p0305
p0306

what could be causing this?
the engine sputter and shaking on startup are my only noticeable symptoms.

more info:
when i changed the plugs i did noticed some oil on the old spark plugs, the old boots looked somewhat dry though

also, in the following pic (not my car):

the circled part was cut off from the intake tube (?), the guy at the garage simply taped it up with electric tape as a patch for now (said that would be fine...)

any ideas guys?
hopefully its not the gaskets : (

Change all coils and plugs and while your at it change the valve cover gasket

Any thing with p0"3"05 is a cylinder misfire

 

[stockls]

sigh.......

ok let me give you little story on my LS
I purchased my 2002 v6 LS back in december with 200000KM on it, had misfire cyl 1 & 6 upon purchase (ran the codes before buying).

so I bought a set of visteon coils on ebay & NGK iridium plugs (160$ + 60$)
about 2 weeks ago i installed all 6 coils and plugs and did an oil change, replaced air filter at the garage (all that cost me 170$): (

Your problem is the iridium plugs also ......if your not running serious 400+HP you don't need the iridium ... The iridium plugs can mess up your valves or destroying the motor get the ngk R's ASAP

 

[oddball]

Wait - that pic is a v8, but you said you have a v6? Very different intakes.

Regardless, almost every modern intake tube has a similar configuration with large bulges hanging from them. They are there to make the intake quieter. It's fine to remove, as long as the hole is sealed well. Sufficient amount of tape will do that. You might notice a high pitched whine that was previously muffled by that chamber.

 

[marcredd]

Your problem is the iridium plugs also ......if your not running serious 400+HP you don't need the iridium ... The iridium plugs can mess up your valves or destroying the motor get the ngk R's ASAP

What supporting facts do you have supporting your post regarding the Irdiums? Not sure I agree at all with your opinion. I say so because I ran NGK Iridiums in my original 3.9 for over 104,000 miles. I also have them in my current engine as well.

 

[LS4me]

What supporting facts do you have supporting your post regarding the Irdiums? Not sure I agree at all with your opinion. I say so because I ran NGK Iridiums in my original 3.9 for over 104,000 miles. I also have them in my current engine as well.

Same here. I've had them in my '06 for ~40K miles.

 

[Wicked Ace]

Your problem is the iridium plugs also ......if your not running serious 400+HP you don't need the iridium ... The iridium plugs can mess up your valves or destroying the motor get the ngk R's ASAP

If your going to make these kinds of assertions you should offer proof as to why you make that claim.
I on the other hand disagree. I have run NGK iridium in several vehicles over the last 10 years and I have been happy with their performance.
Also as an aside I NGK is the manufacturer of many OEM spark plugs. I'm not certain about Motorcraft but I do know they make AC.

 

[marcredd]

I was not aware but learned that NGK came as oem in the gen 1's. I think Stock repeated information given to him but it was incorrect information from the beginning.

 

[marcredd]

Borrowed from a Honda forum but an interesting spark plug review nonetheless.

http://hondamix.com/showthread.php/222-Spark-Plug-Tech-Guide

 

[BlackLS06]

If your going to make these kinds of assertions you should offer proof as to why you make that claim.
I on the other hand disagree. I have run NGK iridium in several vehicles over the last 10 years and I have been happy with their performance.
Also as an aside I NGK is the manufacturer of many OEM spark plugs. I'm not certain about Motorcraft but I do know they make AC.

I was not aware but learned that NGK came as oem in the gen 1's. I think Stock repeated information given to him but it was incorrect information from the beginning.

And for gen II also NGK.

 

[marcredd]

Learned something again. Thanks for the heads up Black.

 

[Ultrastar]

What do you mean by somewhat dry?

what i meant was that it wasn't oily except for some sticky dirt on it

Replace your valve cover gasket same problem im having

do you have the same symptoms? like the car shaking and sputtering for the first few mins of startup?

and if so did changing the VCGs fix it for you?

Change all coils and plugs and while your at it change the valve cover gasket

not sure if you actually read what i wrote but i changed all coils and plugs 2 weeks ago :shifty:

Any thing with p0"3"05 is a cylinder misfire

yes i know lol.... thread title

Your problem is the iridium plugs also ......if your not running serious 400+HP you don't need the iridium ... The iridium plugs can mess up your valves or destroying the motor get the ngk R's ASAP

not sure how credible that info is, i did my research and as far as i know iridium was the best i could get

Wait - that pic is a v8, but you said you have a v6? Very different intakes.

Regardless, almost every modern intake tube has a similar configuration with large bulges hanging from them. They are there to make the intake quieter. It's fine to remove, as long as the hole is sealed well. Sufficient amount of tape will do that. You might notice a high pitched whine that was previously muffled by that chamber.

thanks for the info oddball (lol)
yea thats not my car it was a pic i found on the internet that happened to have the part circled.

the hole where the bulge part was attached on the intake tube was taped, but the bulge part is just sitting there, would removing the tape and re-taping the 2 parts together make a difference?
I thought I had an exhaust leak somewhere but everything checked out fine, i guess thats where the noise is coming from, i did notice it was under the hood

id like the get it as smooth and quiet as possible

and could that have anything to do with the misfires at all?

Borrowed from a Honda forum but an interesting spark plug review nonetheless.

http://hondamix.com/showthread.php/2...lug-Tech-Guide

thanks for the link marcredd

i think this was actually the exact same thread i read before getting my plugs haha

 

[oddball]

thanks for the info oddball (lol)
yea thats not my car it was a pic i found on the internet that happened to have the part circled.

the hole where the bulge part was attached on the intake tube was taped, but the bulge part is just sitting there, would removing the tape and re-taping the 2 parts together make a difference?
I thought I had an exhaust leak somewhere but everything checked out fine, i guess thats where the noise is coming from, i did notice it was under the hood

id like the get it as smooth and quiet as possible

and could that have anything to do with the misfires at all?

FWIW, 'oddball' has been my nick/screenname/alias/whatever since they were called "handles".

If that baffle has been cut off, then just remove it. It's no good. Taping it back on would surely fail and leak air. Just make sure the hole is taped really well - like several layers of electrical tape.
As long as the tube isn't leaking air, then it doesn't have anything to do with the misfire. If it is leaking, then the MAF isn't getting the correct reading, and it'll run poorly, which could seem like a misfire.

 

[tireman]

You say?

Oil on plugs? You must change the valve cover gaskets if they are leaking oil, you should have changed them when you changed the plugs and coils on the V6. Many have had misfires from oil on the plug. So simple. I use NGK platinum plugs, no problems. I changed the VC gaskets on my V6, leaking oil.