Pics of spark plugs with 58,000 miles (opinions please)

[john_ertw]

I went to check the spark plugs in our 99 Olds Silhouette minivan yesterday (It uses the same V6 3.4L engine used by the 99-04 grand am). I only checked the front three because the rear three are imposible to get to (it's even worse than for a grand am which I also have). Just like for the Grand Am, the manual says they should be good until 100,000 miles, but I think not.

One thing to note is that this vehicle had an intake manifold gasket leak that let coolant into the oil (I'm not sure if it got into the combustion chamber). This occured when the van had about 25000 miles. At the time it took the dealership 4 visits to figure out why my coolant was dissapearing, so it was driven 2000-3000 miles with the leak. I'm not sure if this may have affected to colour of the plugs.

All three that I checked were identical:
* Original AC Delco factory plugs with ~58,000miles
* 0.080" gap (should be 0.06")
* white coating on plugs

Also I noticed that the plugs on my 02 Grand Am GT with 35,000 miles have the same white coating on them but they are much cleaner (no oil or black carbon) and the gap is just over spec (0.064").

Since I cannot get to the rear three I used my dremel to clean these up and put them back to 0.06" and reinstalled them. Is there any chance this could do any harm?

I tried to find out what the white plugs meant and what I should do about it but couldn't figure it out. Should I be using a different heat range?

http://www.geocities.com/pencilonly/spark1.jpg http://www.geocities.com/pencilonly/spark2.jpg http://www.geocities.com/pencilonly/spark3.jpg http://www.geocities.com/pencilonly/spark4.jpg

[doobiess]

ya those are pretty worn.... i assume you dont drive your car too hard or run on the highway much? but they are about right a little on the white side... showing its running a little lean. Which can cause that is a dirty air filter clogged fuel filter... dirty o2 sensor.. and yes they could going even if the light dosent come on. Also i just found out why my car are really white plugs is my cat is somewhat clogged.. and for you to test that.. is drive the car until up to norm operating temp. and then reach under your car. and touch the pipe behind the cat... meaning the side going to the muffler and see if its really hot... if its only warm and then quickly touch the cat.. and WARNING it may burn you.... but if it feels alot warmer... you need a new cat.... but what you should do is replace the plugs... run the car for about 10k miles and then show us the pics...

Also do you use many fuel additives.. they will cause plugs to foul up...

[92CamaroRS]

the white stuff and bumps on the plugs are from coolant getting into the combustion chamber. so if the intake manifold has been fixed that is good.

[john_ertw]

The vehicle is not driven very hard, but is used on the highway for decent lengths at least once a week. I change the air filter every 20,000km or so, but never touched the fuel filter or o2 sensor.

The vehicle had an emmisons test a few months ago and passed with no problems (I didn't even bother driving it a while befroe the test to warm it up since it was still under warranty for emmisions and I figured if it fails, gm would be on the line for fixing it. Because of this I don't think there is a problem with the cat.

Fuel additives were only used once about a year and a half ago to try to fix a problem with the fuel sending unit (that was the dealers idea).

I will be driving the vehicle to work on long highway drives (50miles each way) every day during the winter. I hoping that will clean out the carbon.

[doobiess]

well i would say get a new set of plugs and personally i tend to stick with a standard plug not the fancy 200$ something plugs that people think that make thier car race cars... stick with the standard... but i would say nothing to worry about everything looks pretty good...

And as for using your dremel no it wont harm

I would say everything looks ok... just make sure you have no major mileage drops from tank to tank... or any big hp drops or anything like that... and if not i would say good to go

[john_ertw]

Originally posted by doobiess
well i would say get a new set of plugs and personally i tend to stick with a standard plug not the fancy 200$ something plugs that people think that make thier car race cars... stick with the standard... but i would say nothing to worry about everything looks pretty good...

And as for using your dremel no it wont harm

I would say everything looks ok... just make sure you have no major mileage drops from tank to tank... or any big hp drops or anything like that... and if not i would say good to go

That sounds very reasonable. I hope to get them done within a few weeks and will either go with the stock AC Delcos (which I know have no problems) or with the NGK Irridums which I have read work well in this engine.

[tenspeed]

To me, the plugs look normal but worn.

Today's engines are designed to run hot and lean for best fuel economy. A little whiter is too lean and a little darker is too rich or burning oil. I wouldn't worry about the plugs but I would change them. They look like they're just about done.

[LoneRangers15]

I can't believe you didn't destroy a bearing driving 2000-3000 miles with an intake manifold leak. Consider yourself lucky.

[john_ertw]

Originally posted by LoneRangers15
I can't believe you didn't destroy a bearing driving 2000-3000 miles with an intake manifold leak. Consider yourself lucky.

I know. That dealership really pissed me off and I haven't been back since. I actually noticed white gunk under the oil filler cap and had to point that out to the service advisor. I called GM to file a complaint during the process and was told that I had to get the problem repaired at that dealer since they started work there and GM didn't want to pay for another shop to do the same diagnosis as they did.

[92CamaroRS]

if i were you i would have made a fit and REQUIRED that they replace all the bearings in the motor.

[john_ertw]

Originally posted by 92CamaroRS
if i were you i would have made a fit and REQUIRED that they replace all the bearings in the motor.

Unfortunately it occured when I was much less informed about the problems that antifreeze can cause in an engine. I knew it couldn't be good, but didn't realize it could be detremental to the engine. If I recall correctly I did have an oil change in between which may or may not have helped.

[AeR0]

with plugs like that im glad to see you changed them!!

mine looked like that too and i accelerate hard / do alot of city/highway driving..

good to see the cylinders have some nice new ones!

[HeyDace]

Clean 'em, regap 'em and chuck 'em back in. You could get another 10-15k outta them....j/k. They look normal for 58k.

[john_ertw]

Originally posted by HeyDace
Clean 'em, regap 'em and chuck 'em back in. You could get another 10-15k outta them....j/k. They look normal for 58k.

If it was a four banger that had easy to access plug I may have considered this. But with the hassel of getting to the back three you would have to be crazy to get them out and not put new ones in... even if the old ones are in good condition.

Now I have to decide between the stock AC Delco platinum plugs, AC Delco iridium plugs (being used on the newer 3.4L engines by GM), or NGK's Iridium plugs. Decisions, decisions.

[doobiess]

why dont you use some Ac Delco super quad dual spark iridum platinum gold super conducter plugs.... sorry had to say that.. i say use the basic of plugs.. most dependable

[Pte Socks]

Or you can can get some double platinums. They cost me a pretty penny but they wont be needing any servicing anytime soon.

[john_ertw]

I've heard that NGK makes AC Delco Iridiums. I am leaning on the iridiums and if they are the same plug price will decide.