Hey,

What can you tell by looking at these pictures of the current condition of my spark plug? I'm thinking that my engine is running a little lean? By the way, my car has 53k miles on it.
http://www.slakker.net/maxima/Picture047.jpg
http://www.slakker.net/maxima/Picture048.jpg
http://www.slakker.net/maxima/Picture049.jpg

Thanks.

 

Dude its time for new ones, Now is the time to go and Get Coppers

 

They look excellent ot me... normal wear, nothing wron to note on those 53k miles plugs!

 

yes those plugs are bad
Normal fiiring spark plug will have a minimum amount of depos**** on it and will be colored light tan or gray.
The plugs you have now are overheated. A overheated spark plug can be noticed by a white or light gray blistering of the insulator.
Over heating can be caused by many things... like your said a lean air/fuel mixture, using to low octane, detonation, problem with the cooling system, advanced ignition. I would replace those plugs as soon as possible


Mike

 

OI! yes...please replace, for the love of your car!

 

See, this Acura guy is trying to keep you down. hahaha j/k...

 

Before you do anything, find out why you're running so dang lean. That's going to kill your engine eventually, even if you don't have any boost or juice.

 

You are definetly running hot. When I took my plugs out at about 60K miles, they came out slightly tan/brown. I have never personally seen a plug that hot before.

Check for a lean running condition, filter, pump, injector, etc.

 

Hey,

The flash made them look whiter than they really are, but they're still whiter than they should be. My car is running fine though and I'm getting about 400miles/tank. Nothing done to the engine. Maybe that's why my o2 sensors are tripping the ECU/are damaged at only 53k miles I use 93 octane most of the time. If it's not one thing it's something else w/my car

Thanks.

 

Those plugs made me laugh out loud, till I read the part about the flash. Look a bit lean

 

I've never seen that color in particular, but it doesn't appear to be too bad especially for 53K miles. Definitely change them though! I have had deposits like that when I used EXCESSIVE fuel cleaner(Chevron w/Techron), however it was red.

Do you use any fuel system cleaners?

Also, if you are really running lean and you can't determine a fuel delivery problem and fix it, I would consider going 1-step colder plugs. I've had good luck doing that on older vehicles, however it's a bandaid to a more serious problem.

I would check the new plugs at 30K and report back.

 

If you see red on the plugs, it's MMT. It's the lead substitute in unleaded gasoline. You'll find it a lot of your exhaust stream as well.

 

It's the "techron" Chevron puts in their fuel system cleaners?

That's all I used and the plugs were quite red.

 

The red would have occured regardless of whether the techron was used. If you see excessive red on your plugs, you may be running a hair rich, or low in temp and not burning off the MMT which hepls raise octane or anti-knock index of the gasoline. If you are running very rich, it starts to appear more brown and black as other components in the gasoline begin to burn less.

A little reddish brown is fine and normal. But if it is quite red, I would look to another gasoline distributor. MMT will eventually contaminate your O2 sensors and cat.

 

Ok, now you have got me intrigued.

Background:
This is NOT on my Max, but on a '93 Sentra w/140K miles. It has been plagued with a medium PART throttle predetonation problem, since 50-60K miles. Nobody has been able to solve it. Anyways, I have been running Chevron Premium fuel, since 60-70K miles RELIGIOUSLY. I changed the plugs at 90K and they were used, but no signs of any problems(lean, rich, etc.). So, I put in the normal heat range copper NGK plugs and drove until 120K, still having the detonation issues especially during the hot summer time. Then at 120K I changed the plugs and again they looked normal, HOWEVER I was mistakenly given one heat range hotter plugs and I installed them without noticing. I apparently compensated when I reset the timing, because I didn't notice any more detonation than before. So, with the hotter plugs I began dumping in Chevron w/Techron fuel system cleaner every couple thousand miles, hoping to slowly reduce some of the suspected combustion chamber deposits causing the detonation. Again, this did nothing to help the detonation, so I decided to switch to one step colder(actually TWO steps colder than the current set of plugs once I realized the mistake) than OEM after approximately 15K miles. Now after 15K miles these plugs were covered in a BRIGHT and I mean BRIGHT red deposit. Exactly like his plugs, maybe even worse, but instead of white they were red.

Ok, so after 15K miles of adding in Chevron w/Techron fuel cleaner with one step hotter than OEM plugs, I had these RED deposits. So I doubt that I was "running a hair rich, or low in temp and not burning off the MMT", because most likely I was running hotter combustion chamber temperatures and definitely not running rich.

Any other ideas? This problem has stumped myself, numerous Nissan and non-Nissan mechanics, and according to my engine builder friend the root of the detonation is most likely combustion chamber deposits that would probably cause too many problems if I took drastic measures to use "Amsoil foam" or something else that would break them down.

 

In your case, you are burning very uncleanly. Combustion chamber deposits have now caused poor burning as well as hot spots. Just go out and get BG or Kleen-Flo or GM intake cleaner. Follow the directions for cleaning. Part of it is spraying the cleaner into the tb with the engine running. You will probably need to blip the throttle a little with your left hand on the throttle wheel, while you spray into the tb with your right hand. Go through almost an entire can. Then let it sit in your combustion chamber for about 15-20 minutes. Then flush out, and spray the rest into your engine. Go for a drive, atleast 20 minutes, and change the oil. This will get out 90-95% of the deposists out.

I'm assuming you have clean injectors with your continuous use of the Chevron. And after this cleaning procedure, you should have a clean combustion chamber as well. After cleaning, try running copper plugs of stock heat range, stock timing, and recommended octane (not recommended lowest, but recommended).

 

So you still think the RED didn't come from the Chevron cleaner? I don't see how it could have come from anything else.

Yeah, your suggestions are pretty much what everyone tells me EXCEPT I believe if I do that it will cause even more problems on such a high mileage motor. If I knock all the carbon buildup from around the ringland area, it will probably start burning oil which I can't live with. Right now the detonation only occurs under partial-to-medium throttle and is not too bad plus I pass emissions. Any detonation is more than I care for, but this car is just a beater and I don't want to have to replace it by getting aggressive with cleaning.

Once it does die, I can't wait to pull that engine and tear it down to see what exactly was causing it.

Thanks for your help though.

 

Most fuel injector cleaners are basically diluted solvents, in particular toluene, and certain alcohols, occasionally kerosene. None of them leave coloured deposits other then possibly black from low temp burning.

If you could provide information on the content of the Chevron, I could give you more information. I will say this, I used to use Chevron with Techron Fuel System cleaner on my old Volvo 850 Turbo, and I never got noticeable red deposits (sparks always were brownish).

Good luck on figuring out your conundrum.

 

Thanks!

 

I'm glad you guys solved a problem: I'll use these plugs until 60k and than do a tune up.

Peace.