Originally Posted by imidazol97
The #3 plug shows a similar but smaller buildup of carbon on one side toward the sidepost. It is not glassy looking like on the #6 plug. But it does show peaks protruding toward the side post.
So I've replaced two spark plugs with iridium plugs gapped to .060 that I had taken out.
All coils and the ICM have been exchanged with my perfectly running 98 leSabre series II.
I have started and driven the car many times trying to get it to do this again. It finally did miss this morning after sitting for 40 minutes after a short drive to my coffee place. When I started it, immediately there was a noticeable miss, or unevenness. It was a single miss, not the loping heavy miss I had experienced at times before where I thought two cylinders were not firing right. Idled for 10 seconds hoping for engine light and it never came on. I was hoping to get a cylinder recorded.
I also think I feel a slight, short miss while driving that lasts a 1/2 second or so, but rare.
Injector? I have just put in Techron fuel system cleaner on this tank of gas, long after the initial problem.
Could coolant seeping into intake cause a plug to end up with the glassy deposit on #6 in the picture I posted?
I'm not losing coolant in any amount measurable on the reservoir. I do have a slight external seep on cooling at the bypass tube that'* been there since the mechanic did my Upper and lower gaskets with FelPro metal 3 summers ago. I plan to replace bypass tubes and put on a new tensioner along with the rear valve cover gasket, since that stuff has to come off.
switch injectors #6 and #4.
send oil sample to Blackstone to be sure no coolant is in coolant--last sample was late last fall and it was perfect.