Spark Plug question

[McLin]

Hello,

looks these plugs ok? Every spark plug have 2 pictures...
3.8L V6 98 Chevy Lumina with NGK TR55 plugs

Pictures

[SleepyHead98]

ERmmm. Why are some pink and some not? On the electrode shroud. You got pink coolant by any chance? Looks vaguely familiar to a 3.8 with a bad head gasket.

on second look, I would put money on that. Bad head gasket, you can see the whitish pink buildup on some plugs. Labor intensive, but you can get it done under 250 if you do it yourself. Get the heads planed before you do the new gasket. Msg me if you need more help/pointers.

[Schurkey]

Gasoline additives can cause yellow, green, pink, or rusty-orange coloration on the porcelain. I wouldn't worry about it if you're not having to add coolant.

I'd clean the threads, apply some anti-seize, and screw 'em right back in.

You can clean the porcelain with a propane torch (NOT MAPP gas, or acetylene) so they're nice 'n' white again...I don't think I'd bother in this case.

[SleepyHead98]

Meh, I would put money on it, If Im wrong Im wrong, but ... Ive seen this before, exactly. How much coolant do you add a week? Or did it get hot, and suddenly you notice there wasn't any coolant? Im am interested, but some reason I know Im right.

[McLin]

I dont need to add coollant on the lumina. I think I have to add 200ml in 6 month. The last 2 picture are from rear bank. The other six from front bank. Which on did you mean is more pink or are all the same?

[Schurkey]

Originally Posted by McLin

I dont need to add coollant on the lumina. I think I have to add 200ml in 6 month.

Six ounces of coolant in six months is probably not an issue. Ideally, you wouldn't have to add any coolant for years at a time, but less than a cup in six months doesn't worry me.

Unless the engine ran poorly, I'd clean and anti-seize the threads, check the gaps, and screw those plugs right back in.

[McLin]

I had sometimes misfirer without setting a trouble code, so I thought that I have problems with these ngk spark plugs.

I can't say what the the misfire problem is, I changed everything and spray two bootles of starte fluid around the whole engine. The only think I changed bevor the failure begun was the AC Delco spark plugs with NGK TR55

[Tech II]

Always use OEM plugs on GM cars.....

[SleepyHead98]

Okay so you are losing coolant, not as much as I thought, but you are still losing it, I bet it will get worse over time, I still bet you have a head gasket problem.

If it was just the "additives" to the fuel, wouldnt all of them be pink? Why are only some pink?
Where the two colored ones next to each other? if so, it further goes to my point, you have a leaking head gasket.

200ml, =1/5 L. No too bad, Might be able to use KW block sealer on it. Flush out all old coolant, put in KW block sealer (orange pop top can costs 8 bux) put that in there with DISTILLED water, run it for 500 miles up to 1000. Dump and refill with you choice of fluid (I recommend walmart 8 dollar blue bottle stuff, Dex cool is what caused your gasket to leak) You will not have freeze or boil over protection. THis works by the way. I did it to my car which lost 1/4 inch of coolant a week, and stunk like burning coolant, this sealed it up.

[Tech II]

Coolant leak on a 3.8?

I would be leaning towards the plastic elbows or the o-rings on the tensioner assembly, water pump, upper plenum gasket, upper plenum(EGR hole), lower intake gaskets, BEFORE I would be thinking head/head gaskets.....

[McLin]

I changed all the stuff in last years. New lower intake gasket, new plastic upper intake include all gaskets. New elbow. I did not loose any coolant after repair but the misfire was there. I think it leaking on top of the power steering where the heater hose goes into the car.

Oh and no cooland in oil an vice versa.

The plugs are all pink front and back bank. I did not picture the last 2 spark plugs because the daylight was gone and I put all stuff in the engine.