What is this spark plug telling me?

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Sep 2, 2010 | 08:01 AM

#16

bw_hunter

Registered User

Joined: Jul 2002

Posts: 1,942

From: Kissimmee, Fl, USA

Quote:

Originally Posted by Jasonz28camaro

stick your finger in the hole to see if there is oil. If that is oil you will need to take off your valve cover and andcheck your spring, it could be hanging the valve open and allowing oil to drip and get on your plug.

That doesn't happen unless you have a bad seal on the valve guide. If the seals are good, the valve beaing open won't allow oil to pass. There are, obviously, always valves open when the engine is off.

Sep 2, 2010 | 10:59 AM

#17

motorking

Registered User

Joined: Sep 2010

Posts: 10

Quote:

Originally Posted by AdsoYo

For as long as I've been running this new engine it's had a wierd back and forth shake if I hold speed at an RPM below 2K in any gear. This last weekend I decided to focus on the spark plugs as a possible cause.

I have been running Autolite 103's by mistake this whole time and after reading many posts on this thread and others I realized I needed a hotter plug and bought a set of NGK TR-55's and gapped them at 0.045".

After about 50 miles of mixed driving, I pulled plug #4 and took some pictures with my cell phone camera. Sorry that they're kinda blurry but the only fine details you're missing are the "layers" of color change on the ground strap. The electrode looks new, the porcelain isn't discolored and the base ring has one full turn of color.

Looking at these pictures can you guys see anything I should be concerned about or does it look normal?

Hi,
I am the technical manager at Autolite. If you can send clear hi res photos of your plugs I can have our race engineer look at them and tell you what it means. The photos posted really say nothing. You also should be very carefull going to a hotter plug on any modified car. Unless you have fouling issues or cold start issues, your running the risk of engine damaging pre-ignition.