Team Camaro Tech banner

1 - 8 of 8 Posts

·
Registered
Joined
·
934 Posts
Discussion Starter #1
Hey guys, I have a 94 Z/28 with an LT1 motor. Car sat for about 6 months or so with about a 1/4 tank of gas in it. It was topped off with new gas and run. It runs fine with no problems, but after about 2K miles, the plugs were taken out. The plugs below have 2K miles on them. I just can't figure out why one plug out of the 8 has a red insulator.

Again, the car runs and performs fine with no problems.....it just has one red colored spark plug when the rest look normal.

No additives, no hard running, used only 93 octane fuel. It has a lumpy cam and headers.

Any ideas?

Here is the red one and one normal one........



 

·
Registered
Joined
·
5,277 Posts
That is weird. I've never seen that before. I also noticed that the center elctrode still looks nice a square compared to the other plug that has a slightly burned electrode (normal). Also the soot ring on the red plug is practically non existant compared to the other plug. Looks like the mixture on the red plug was a bit lean IMHO. Lets see what others say.
 

·
Registered
Joined
·
934 Posts
Discussion Starter #3
***bumpage***
 

·
Premium Member
Joined
·
1,158 Posts
I've read plugs in my boat after changing engine setups etc (WOT) wide open throttle..had a person who writes on line reviews look at plug photos. He indicated reading plugs with clean unleaded fuels these days is nearly impossible (visually).

Anyway..according to this poor gas :).

Normal, but with red coating: The red coating is a result of the additives in lower-quality unleaded fuel and will be visible on the plug's ceramic insulation. The red coating is not an indication of any engine problems.

http://www.automedia.com/Spark_Plug_Diagnosis/ccr20030701sp/1


This is pretty good...

http://www.dragstuff.com/techarticles/reading-spark-plugs.html
 

·
Premium Member
Joined
·
8,375 Posts
No problems if all the plugs were the same, but they're not. I would look for some kind of fluid leak like a head gasket or intake. The plug having no carbon is an indicator. Water cleans carbon. Antifreeze might make that color. Keyword; might. I'm betting a seeping intake gasket. Try re-torquing the manifold.
 

·
Registered
Joined
·
384 Posts
I've seen green antifreeze leave a green tint on the porcelain. Are you using Dexcool? I would guess it could leave a red tint, but I've not seen it personally.
 

·
Premium Member
Joined
·
8,375 Posts
Bump
Sure would like to know what Joe learned.
 

·
Registered
Joined
·
934 Posts
Discussion Starter #8
Well, when we installed a new set of plugs, the car has hardly been driven much since then to get another analysis, so at this point, we are just waiting to drive it.

This red plug was on #6, so if there is a coolant leak, it should not get into the #6 hole....unless of course the head gasket is leaking and there is no sign of coolant loss whatsoever. I think we will put a few more miles and check the new plugs again and see whats up......it's just a waiting game from here.

Thanks for the support on this kinda weird question.

~Joe
 
1 - 8 of 8 Posts
Top