[John's_stang]

ok so im neww...
but anyway i have 2 problems..

first one.. i recently put a new intake mani. on cuz the stock one crack as usual... and after the first day was running good... then the next day it began bucking around 1300-2000 rpms... and would play out and more throttle was given... i replaced the iac valve and still continues... any ideas?

2nd one... i was pulling the spark plugs to check and see if they would have anything to do with it... and as pulling the passenger side one... each spark plug had oil in it... any ideas there as well...

[RyanGT]

Keep it to one post, will be easier to diagnose

[RyanGT]

Oil on the plugs or in the plug hole? Getting any smoke? Oil in the intake manifold?

[RyanGT]

The bucking at rpms and fouled plugs (if thats what your talking about) is probably related. I would triple check all vacuum hoses also. And replace the plugs and also pvc valve (could be getting more blow back than normal). A way to make sure is to check if there is oil in the intake..

[RyanGT]

Are other plugs fouled also (im just guessing since your not replying)? Did anything else get replaced when you did the intake? If only one side noticeably different you have a problem. It could be intake gasket, but that would be more to do with coolant than oil. Which would explain why only one side is. Really cant help without more info.

[John's_stang]

i replaced the pcv valve when i got it which was bout a month or so ago... there no smoke coming from the car...
idles and runs good if wide open...
oil is on it from a lil above the tips and on up... the last cylinder was soaked in oil and gas..
the tips were dry... i think i got all the hoses on correct... far as i know... a guy at an auto parts store told me to check for vacuum leak around mani. usin carb cleaner... i did and nothing sucked in and caused engine to surge?

[John's_stang]

well let me correct myself... oil is on it from the threads on up

[John's_stang]

all the plugs were fouled... looks like its been awhile since they were replaced last...
and only one side has oil in them... and nothing else was replaced with the new manifold... except the iac valve which i replaced today...

[RyanGT]

Carb cleaner is a good start. You will notice the idle change when you find a leak, because it will get burned. If it is soaked in gas it might be ignition problem. But it is all 4 cylinders so it makes me think it has to be something one side related...

So your saying its on top of the plug, like in the hole where the coil goes? Or from the threads to the firing tip. Lol sorry just gotta make sure

[John's_stang]

its from the threads up to the coil... i did the card cleaner earlier... didnt notice a change... unless im just not hittin the spot

[RyanGT]

If all plugs are fouled then replace them. That one cylinder thats the worst might not be firing at all, which would be the soakage in gas.

I would double check if you have oil in the manifold tomorrow (and replace the plugs for sure). That might be the problem right there, just showed up by coincidence.

[John's_stang]

the firing tips are dry

[John's_stang]

how would i go about checking for oil in the manifold? pulling the manifold again?

[RyanGT]

Ok then im totally lost lol. Only way you could of got oil on the outside of the plugs (the hole, not fouling) would be to have a loose plug... or oil got dumped on it accidentally. If its on the outside, its causing it to not fire all the time. I have heard of coolant in the plug holes but never really oil...

If its all on the outside clean it up, get all 8 new plugs, and make sure the cops are as clean as you can get them.

[RyanGT]

If its on the outside i wouldnt bother looking in manifold. But it would be easy, just take off the tb/plenum and get a flashlight and look at the runners, maybe a long q tip. MAKE sure not to drop anything in there, or get it dirty. Careful!

[John's_stang]

well its just those 4 cylinders are oily like the coils arent oily just spark plugs.. i stuck the socket down in there to pull the plug off and it had oil at the base... maybe the cylinder gasket is bad?
ill check the oil in the manifold tomorrow when i get off work.. the inside mani should be dry tho right? what does it mean if there is oil in it...
could this be why it is bucking?

[John's_stang]

well i lied.. one coil had oil on it at the bottom

[RyanGT]

I dont see how oil could pool in the plug hole though. I have a different manifold so trying to go off of memory. But that is your problem (dont know the cause of it though). The intake will have some oil in it, because of blow back. Its excess that is bad. Its brand new, so it should have barely any if none. If it has a lot it could be a problem (time for a catch can). Oil lowers the octane in the fuel. And can foul the plugs if not burnt.

[John's_stang]

so the spark plugs and oil in it is most likely the problem for the bucking...
what is it if oil is in the mani?

[RyanGT]

That would just be compounding the issue, i doubt it is anything if your plugs are not fouled. If the outside of the plugs have oil on them, they will not fire as strongly (or sometimes not at all) and cause weird problems. Hesitation is a big one. try to clean the coils (inside) with an electric cleaning compound. Like a MAF cleaner.

So if i were you i would replace the plugs (do them all), and clean the cops. And take it for a drive. I wouldnt look for oil in the mani yet. Your not fouling on the inside.