[majdmajd]

Originally Posted by easttxss

He is in Israel, I believe they use a different rating system and their 98 is our 93.
I agree with cleaning the MAF and replacing the front O2 sensor, they do wear out.

Should I do both upper and lower o2 sensors?

I do have a vibration in my car on idle... and you can feel it at the back from the exhaust as well.

But the car isn't smoking at all, although the exhaust tips are black with carbon.

[majdmajd]

Originally Posted by buck50

I would expect all plugs to look about the same. Your bottom one in the photo does not. Appears your car is 2.0L turbo 4? Is so plugs suggested by GM in USA market are 12681659 not the number on your used plugs? You mention plugs were replaced once at 50K, so how may miles on plugs in photos?

I changed the spark plugs when I posted this thread.

Coil packs are new as well all 4. ACDELCO.

Vibration in the car on idle is still there, i had a knock sensor code pop up.

[majdmajd]

Originally Posted by buck50

I would expect all plugs to look about the same. Your bottom one in the photo does not. Appears your car is 2.0L turbo 4? Is so plugs suggested by GM in USA market are 12681659 not the number on your used plugs? You mention plugs were replaced once at 50K, so how may miles on plugs in photos?

Those plugs in the photo were there from 50k. (Old spark plugs) I changed them recently when i posted this thread.

Spark plug number: AcDelco 41-125 12681659

[majdmajd]

Originally Posted by Spaceme1117

Spark plugs don't look to bad.

But to me it looks like you are burning some oil.

How is your oil level?

My car does eat oil a bit, i always check the engine oil.

I use Valvoline 5w30 Full synthetic Max Life

[ctrlz]

Originally Posted by majdmajd

Those plugs in the photo were there from 50k. (Old spark plugs) I changed them recently when i posted this thread.

Spark plug number: AcDelco 41-125 12681659

Do you have the AC Delco part number for the plugs that were removed?
It looks to me like 19377649, but there is no photo where I can see the whole number. And I can't find an Ac Delco part number for 19377649.
Since those plugs showed a possible problem it would be useful to see those side-by-side with the correct plug to get an idea if they share the same heat range.

[Ventmaster]

Originally Posted by majdmajd

Those plugs in the photo were there from 50k. (Old spark plugs) I changed them recently when i posted this thread.

Spark plug number: AcDelco 41-125 12681659

OK- so we've got the right plugs in now but still getting the occasional knock. You mentioned, "I have a feeling i should put back the stock inlet with the baffle to reduce the amount of carbon my car is making from oil."

Not sure I agree with, or follow your logic here. Do you know if the blackened plug was in the cylinder that had a bad coil? Just curious- likely an unimportant detail now that we've got all new coils and plugs.

But the bit about a stock baffle, well maybe we should return that to stock and please mention any other changes you've made (or are aware of others made) to the car. Sometimes it feels like you're cross examining a witness to draw out the info you want... ya know?

BTW- save your money and quit the fuel additives. They often just muddy the water of plug "reading" Just get a name brand gas with a good rating. Here in the States we have a "Top Tier" rating for gas that has a good amount of cleanser packages and octane testing to earn that rating. Additives often just "muddy the water" when it comes to spark plug reading.

Good luck- I'm still betting this is an easy fix and keep in mind that knock sensors can pick up rattles in the exhaust (pipe movement or knocking on other parts of the undercarriage while driving), or any other loose parts.

Good luck, keep us posted, and remember to have fun!
BTW- my exhaust pipes are black as well.

[ctrlz]

Originally Posted by Ventmaster

OK- so we've got the right plugs in now but still getting the occasional knock. You mentioned, "I have a feeling i should put back the stock inlet with the baffle to reduce the amount of carbon my car is making from oil."

So there is an aftermarket intake? And a knock?
Fortunately these aftermarket intakes never, never, never, EVER cause fuel mixture problems

[majdmajd]

Originally Posted by ctrlz

Do you have the AC Delco part number for the plugs that were removed?
It looks to me like 19377649, but there is no photo where I can see the whole number. And I can't find an Ac Delco part number for 19377649.
Since those plugs showed a possible problem it would be useful to see those side-by-side with the correct plug to get an idea if they share the same heat range.

The number on those old plugs : 19377649

No idea if they're iridium or double platinum.

[majdmajd]

Originally Posted by Ventmaster

OK- so we've got the right plugs in now but still getting the occasional knock. You mentioned, "I have a feeling i should put back the stock inlet with the baffle to reduce the amount of carbon my car is making from oil."

Not sure I agree with, or follow your logic here. Do you know if the blackened plug was in the cylinder that had a bad coil? Just curious- likely an unimportant detail now that we've got all new coils and plugs.

But the bit about a stock baffle, well maybe we should return that to stock and please mention any other changes you've made (or are aware of others made) to the car. Sometimes it feels like you're cross examining a witness to draw out the info you want... ya know?

BTW- save your money and quit the fuel additives. They often just muddy the water of plug "reading" Just get a name brand gas with a good rating. Here in the States we have a "Top Tier" rating for gas that has a good amount of cleanser packages and octane testing to earn that rating. Additives often just "muddy the water" when it comes to spark plug reading.

Good luck- I'm still betting this is an easy fix and keep in mind that knock sensors can pick up rattles in the exhaust (pipe movement or knocking on other parts of the undercarriage while driving), or any other loose parts.

Good luck, keep us posted, and remember to have fun!
BTW- my exhaust pipes are black as well.

That is the only change I've made, the silicone hose inlet with the K&N drop in air filter, but I don't have a catch can... hence the carbon build up. - The only reason why I use fuel additives to try to prevent the carbon out of those valves.. even though it doesn't help much since its a GDI.

"I'm still betting this is an easy fix and keep in mind that knock sensors can pick up rattles in the exhaust (pipe movement or knocking on other parts of the undercarriage while driving), or any other loose parts"

-- Will replacing the knock sensor on bank 1 help? since its the code that came up when I was flooring it? Probable cause of a damaged/faulty sensor?

Please bare in mind, I took the car to 3 mechanics one of which is an American car mechanic and none of which knew the problem after explaining to them what I did and regarding the new coils and spark plugs.
One of them mentioned that it was a cylinder combustion pressure problem..... damn

[ctrlz]

Do you have a scan tool that will let you look at real time data? Fuel trims? You can also see how often the knock sensor code is coming up. It probably requires 3 or 4 events before it posts a CEL.