# Spark plugs pitch Black?



## XEdgeXPassatX (May 12, 2010)

So my car was running really bad. a week ago i replaced the coil/distributor cap/ rotor and now plugs. my car jerked under little load when stepping the gas pedal down. So i replaced the plugs. WEll when i was driving the car seemed to be smoking white. I have a 270 cam with the stock chip... had a performance chip until the people beofre me took it out. Could this cause the car to buck and the plugs to be fouled. OR could i possibly have a bad headgasket.  i am soo flustered on what it could be that i might be trading back to the original owner for another mk3 that runs perfectly. any help would be appreciated


----------



## goodbowler200 (Jul 4, 2008)

*had same problem*

Black plugs means the gas isn't burning. 
When the motor heats up does it run a little better?
If so it could be out of time or some bad valves. 
It sounds like a timing problem because all cylinders are the same.
Try taking the belt off and then turning the camshaft one whole turn and see if that works.


----------



## XEdgeXPassatX (May 12, 2010)

goodbowler200 said:


> Black plugs means the gas isn't burning.
> When the motor heats up does it run a little better?
> If so it could be out of time or some bad valves.
> It sounds like a timing problem because all cylinders are the same.
> Try taking the belt off and then turning the camshaft one whole turn and see if that works.


So your saying spin the camshaft 180 degrees? wouldn't this make the timing ridiculous off. or should i put the engine to top dead center and see if the timing belt is off?


----------



## ps2375 (Aug 13, 2003)

goodbowler200 said:


> Try taking the belt off and then turning the camshaft one whole turn and see if that works.


Don't do that. If your motor is running, it def won't run with the cam 180* out. Black plugs means either it is too rich or you are having a serious amount of mis-fires. Is the CEL lit? Does it "smoke white" all the time or just until it warms up? Any other mods on the motor other than the cam?


----------



## AEG2.SLOW (Sep 13, 2011)

Sounds like it could be a cam position sensor affecting ignition advance too as that would cause hesitation and could lead to the mixture not burning. As far as installing a cam 180* out it does not matter as the cam spins 1/2 the speed of the crank. The only problem is there isn't a timing mark there  If it were 180* out you would roll the whole engine one revolution and you would be back to the original mark.


----------



## XEdgeXPassatX (May 12, 2010)

the car has a 270 cam/ and a header. that is it. it had a neuspeed chip in it but now its gone. cause the idiots who had my car before me took it out. that is it. it also has the techtonics cam gear. thats basically it. i put new plugs in and it helped. i was doing about 95 today on back roads and when i was slowing down and downshifting it was pouring out white smoke but then it went away after i started moving again. im soo flustered and annoyed. i have replaced like i said coil/cap/rotor/plugs it ran good for a lil while but then started running like **** again. anyone can help?


----------



## WannabemkIV (Feb 24, 2011)

It's running super rich if the plugs are black. Check the vacuum line on the fuel pressure regulator but I think a big part of your issue is the 270* cam and stock chip. Change to the stock cam or change to the correct EPROM. In addition to this you may also have a coolant burning issue.


----------



## tdogg74 (Mar 1, 2002)

Do me a favor and post me a good pic of the plugs. Get real close to the ground strap as well.


----------



## XEdgeXPassatX (May 12, 2010)

911_fan said:


> Do me a favor and post me a good pic of the plugs. Get real close to the ground strap as well.


the ground strap from the ignition coil? its like 2 connected together. could this definately be the problem?


----------



## XEdgeXPassatX (May 12, 2010)

thats the plug on the right. the +4 seemed to help a lot. but still jerks and bucks. if its the ground strap that would make since


----------



## tdogg74 (Mar 1, 2002)

No no no....the ground strap is the welded piece of metal that goes from the base ring to up over the center electrode. I can tell the heat range and ignition timing from looking at that.


----------



## XEdgeXPassatX (May 12, 2010)

The plus r still at my sisters


----------



## tdogg74 (Mar 1, 2002)

Those plus 4's are absolute crap in ABA. Throw them in the trash. 

The single prong plug is, in fact, running super rich. You need to do some voltage checking on your sensors. Check the coolant temp sensor, mass air flow sensor, and the front O2 sensor. If any of those need to be replaced, it will make your engine run rich. Time to do some maintenance.

And no, the cam wont turn your plugs black like that.


----------



## XEdgeXPassatX (May 12, 2010)

Well guys i figured it out.. my headgasket is shot.. im thinking that i need a new head also. i think that the head might be warped because no longer than 5 months ago my friend replaced the head in this same car. i know he forgot to change the headbolts when he did it back then. But would i be safe to just change the headgasket and head bolts?


----------



## ps2375 (Aug 13, 2003)

I would have the head checked at a local machine shop for flatness. If it is warped, get another head, if it just needs a slight bit milled off for a good sealing surface, that is OK. And tell your "friend" that the head bolts are only good for ONE use.


----------



## XEdgeXPassatX (May 12, 2010)

ps2375 said:


> I would have the head checked at a local machine shop for flatness. If it is warped, get another head, if it just needs a slight bit milled off for a good sealing surface, that is OK. And tell your "friend" that the head bolts are only good for ONE use.


Alright anyone know how long it takes for a machine shop to look at it? otherwise i might just put new headgasket on it and new bolts. 60 bucks. planning on doing a vrswap in like 3 months so if it lasts that long. im good


----------



## nuff said (Nov 22, 2011)

*black plugs*

with no warning my car would not idle and barely run .I checked many things .the scanner had a misfire code which was obvious.I have new coils.I checked the plugs and they were black as coal ,not sooty dry but slightly oily black .I thought it could be either the maf,map,cat converter,
or boost or vac leak.I pressure tested the system but was air tight,no leaks.Cleaned the plugs.
Restated car and same thing ,smelled gas .I unplugged the maf and ran the car but car ran the same.I was told if the maf was bad,if you unplugged it and the car ran better unplugged then it would be the maf.Wrong,car ran lousy either way.I was going to take the front 02 sensor out in front of converter to see if car would run better,thus showing a cat problem .Then I was going to check the map sensor .I had a extra maf I had bought 5 months previous but after installing last time ,the car ran lousy.so I stayed with the old maf which worked better.I decided to try the old maf and voila!!!! problem solved so far.Car idles good .It is a non oem aftermarket maf so I think I will get a bosch maf and keep the other for emergencies. So for me,oily black plugs and 
very rough idle meant blown maf sensor.


----------



## XEdgeXPassatX (May 12, 2010)

yeah i thought that could be the problem too but when i would unplug it the car did a bunch of weird ****. im sure it was the maf but i sold it so not my problem anymore ha.


----------



## RobBoost (Jul 4, 2014)

nuff said said:


> with no warning my car would not idle and barely run .I checked many things .the scanner had a misfire code which was obvious.I have new coils.I checked the plugs and they were black as coal ,not sooty dry but slightly oily black .I thought it could be either the maf,map,cat converter,
> or boost or vac leak.I pressure tested the system but was air tight,no leaks.Cleaned the plugs.
> Restated car and same thing ,smelled gas .I unplugged the maf and ran the car but car ran the same.I was told if the maf was bad,if you unplugged it and the car ran better unplugged then it would be the maf.Wrong,car ran lousy either way.I was going to take the front 02 sensor out in front of converter to see if car would run better,thus showing a cat problem .Then I was going to check the map sensor .I had a extra maf I had bought 5 months previous but after installing last time ,the car ran lousy.so I stayed with the old maf which worked better.I decided to try the old maf and voila!!!! problem solved so far.Car idles good .It is a non oem aftermarket maf so I think I will get a bosch maf and keep the other for emergencies. So for me,oily black plugs and
> very rough idle meant blown maf sensor.


Interesting. I put my maf housing on backwards while doing my turbo build and now I have a couple black plugs too.
Wonder what makes them so oily though? Is it just a ton of semi burnt fuel causing it?


----------

