Changed back to Stock Spark Plugs

Shipkiller · 11-24-2010, 06:33 PM

I was performing my pre-track day maintenance and one of the things I do is pull the spark plugs out for a visual inspection and re-torquing.

It's been 3300 miles since I put the NKG Iridium IX Spark Plugs in the car.

First thing I noticed is that they are very easy, eg. very little torque required to remove from the head. After pulling out the first plug, I used a torque wrench to measure the break away torque, which was about 12ft/lbs. Never had this issue on the stock Bosch units, but I have never measured the break away torque on the Bosch plugs because I never had a reason to.

Second thing I noticed right off is the carbon arcing on the top of the plug, where the COP contacts the plug. I have never seen this before on any vehicle I have.

Third thing is that threads are extremely dirty and not dry.. some type of liquid on them. not oil, not gas..

but nothing in the plug wells. They were dry.

The tips were clean and free from any type of carbon build up so I will assume that they were burning well.

I still had the old Bosch plugs (in numbered boxes) so I put them back in the same cylinders that they came out of back in August.

I could say that I felt a difference but as we all know, the imagination lies....

I do notice that the engine oil gets up to operating temp faster but the car is not running any hotter. Also, I have noticed lately before putting the Bosch's back in, that when I start the car up in the morning, the car would run slightly (very slightly) uneven for a minute or two and now this has stopped with the Bosch plugs.

We shall see.

Heading out to VIR on Sunday for a two day event...

I will pull one of the plugs when I get back to look for any deltas...

Shipkiller · 01-24-2011, 02:25 PM

I have put them back in.

After running around with the stock plugs for three weeks, my mileage was lower so did some more investigation.

It seems that my spark plug torque wrench was out of calibration and not torquing the plugs enough...

I had the wrench recalibrated and reinstalled.

No more issues.... Never got around to post a status...

roo97ss · 01-24-2011, 04:18 PM

Quote:

Originally Posted by Shipkiller

I have put them back in.

After running around with the stock plugs for three weeks, my mileage was lower so did some more investigation.

It seems that my spark plug torque wrench was out of calibration and not torquing the plugs enough...

I had the wrench recalibrated and reinstalled.

No more issues.... Never got around to post a status...

how much milage diff did you notice?

Joe

Shipkiller · 01-24-2011, 04:31 PM

I lost 2MPG. This was less than was normal.

imom · 06-10-2011, 02:55 PM

Quote:

Originally Posted by Shipkiller

I lost 2MPG. This was less than was normal.

Shipkiller, did you lose 2MPG with stock Bosch plugs or with the NGK? Finally did you stay with stock or NGK...sorry wasn't clear looking at this thread for me.

Shipkiller · 06-10-2011, 03:30 PM

I lost 2MPG with that set of Bosch.

The NKG's have been in the car now for the six months.

It's time for me to pull the plugs and do a visual check.

11-24-2010, 06:33 PM	#1
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	Changed back to Stock Spark Plugs I was performing my pre-track day maintenance and one of the things I do is pull the spark plugs out for a visual inspection and re-torquing. It's been 3300 miles since I put the NKG Iridium IX Spark Plugs in the car. First thing I noticed is that they are very easy, eg. very little torque required to remove from the head. After pulling out the first plug, I used a torque wrench to measure the break away torque, which was about 12ft/lbs. Never had this issue on the stock Bosch units, but I have never measured the break away torque on the Bosch plugs because I never had a reason to. Second thing I noticed right off is the carbon arcing on the top of the plug, where the COP contacts the plug. I have never seen this before on any vehicle I have. Third thing is that threads are extremely dirty and not dry.. some type of liquid on them. not oil, not gas.. but nothing in the plug wells. They were dry. The tips were clean and free from any type of carbon build up so I will assume that they were burning well. I still had the old Bosch plugs (in numbered boxes) so I put them back in the same cylinders that they came out of back in August. I could say that I felt a difference but as we all know, the imagination lies.... I do notice that the engine oil gets up to operating temp faster but the car is not running any hotter. Also, I have noticed lately before putting the Bosch's back in, that when I start the car up in the morning, the car would run slightly (very slightly) uneven for a minute or two and now this has stopped with the Bosch plugs. We shall see. Heading out to VIR on Sunday for a two day event... I will pull one of the plugs when I get back to look for any deltas...
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01-24-2011, 02:25 PM	#2
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	I have put them back in. After running around with the stock plugs for three weeks, my mileage was lower so did some more investigation. It seems that my spark plug torque wrench was out of calibration and not torquing the plugs enough... I had the wrench recalibrated and reinstalled. No more issues.... Never got around to post a status...
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01-24-2011, 04:31 PM	#4
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	I lost 2MPG. This was less than was normal.
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06-10-2011, 03:30 PM	#6
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	I lost 2MPG with that set of Bosch. The NKG's have been in the car now for the six months. It's time for me to pull the plugs and do a visual check.
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