# 3 dirty spark plugs and one clean 1



## chasem407 (Feb 19, 2008)

So for the time being, I put my car back to stock and took the turbo and all the ish off. 

Anyways, the car (mk4 2.0 AEG) feels veryyyyy slow, kinda ironic but I dont remember it being this slow. 

Also, when I rev the engine, there is a nasty rattling noise in what sounds like the valve cover area, its more than just the valve tap. 

well I checked compression and got about 210 on all 4. 

But the spark plug in cylinder 1 was almost brand new looking :screwy: The other 3 were covered in the black like normal. The tip on the spark plug seems like it is firing because its got the whiteish tip. But the base is clean, shiny metal. 

So I dont know if its an injector issue or what.. 


Does anyone know what would cause that? plus I have no CEL..


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## chasem407 (Feb 19, 2008)

bump for someone explaining why one spark plug was clean


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## MonkeyBusiness (Jun 11, 2009)

why did you un-turbo your car? 

pics of said spark plugs? 

what did the spark plugs look like use below as reference


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## Labrador_R.I.P. (Apr 11, 2007)

Hi, 

looks like coolant is going in your cylinder. Do a leak test to see if your headgasket is good. 

Marc


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## chasem407 (Feb 19, 2008)

The 3 look like the normal, used spark plug. The 1 clean one isn't in those pics be there is nothing odd looking about it, its shiny and new looking. 

I'll look into how to do the leak down test, but coolant level has been fine and there is no smoke. 

ps, I took the turbo out bc of an issue with my ECU, i got it solved now, but ill wait till christmas break to put everything back in.


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## MonkeyBusiness (Jun 11, 2009)

I have no explanation for this? did you have a constant misfire on one of the cylinders?


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## chasem407 (Feb 19, 2008)

MonkeyBusiness said:


> I have no explanation for this? did you have a constant misfire on one of the cylinders?


 no, the car feels so powerless though, flooring it in 3rd and i go no where....well at least no where fast  

and I have no CEL which is ubber weird lol 

I wonder if my timing is off


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## Labrador_R.I.P. (Apr 11, 2007)

chasem407 said:


> The 3 look like the normal, used spark plug. The 1 clean one isn't in those pics be there is nothing odd looking about it, its shiny and new looking.
> 
> I'll look into how to do the leak down test, but coolant level has been fine and there is no smoke.


When coolant goes into the cylinder, it ''wash'' the spark plug making it look brand new. It can be a very small leak.

Place your cylinder 1 in TDC during compression
screw your compressed air hose in the spark plug hole using some kind of adaptor
open your coolant reservoir and look if there is bubbles coming out (that means air gets in the cooling system by the head gasket).
do the test engine cold and at running temp. (if you don't find the leak on the first try)

It won't throw a check engine unless massive amout of coolant goes through. Because check engine is mostly for emission problems.

about that rattling noise and the lack of power... is your oil level good ? your engine will make sounds and lose power when the oil level is very low. I know it sounds dumb but I'm just making sure.

Marc


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## chasem407 (Feb 19, 2008)

Labrador_R.I.P. said:


> When coolant goes into the cylinder, it ''wash'' the spark plug making it look brand new. It can be a very small leak.
> 
> Place your cylinder 1 in TDC during compression
> screw your compressed air hose in the spark plug hole using some kind of adaptor
> ...


Well the rattling does sound like the valvetrain is being starved of oil, but the oil level is spot on! I've been thinking about using thicker oil, 10w-40, rather than the 5w-30 I use now. So maybe ill do that soon and see if the noise diminishes.

Also, I should be able to find the adapters needed for the leak down test, Ill check and see if there are those bubbles present.

Thanks for the help.


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## Labrador_R.I.P. (Apr 11, 2007)

Oil pressure is good ?

I use 10w40 synthetic oil in m aeg and it runs smooth. I know somme ppl dont like synthetic but it just stick better on the parts. Solved my oil comsumption problem that way.

Marc


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## chasem407 (Feb 19, 2008)

Labrador_R.I.P. said:


> Oil pressure is good ?
> 
> I use 10w40 synthetic oil in m aeg and it runs smooth. I know somme ppl dont like synthetic but it just stick better on the parts. Solved my oil comsumption problem that way.
> 
> Marc


good to know, Ill try that oil then. I'll have to look into the oil pressure as well..


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