So my car has been driving pretty sluggish for past 2 days, so the day I finally get a chance to check under the hood, things seem to get worse.

So when I parked my car, I start to hear a small knock. So I turned it off right away, and after several minutes, I started it up again. The knock was gone, i let it idle for few minutes and then the knock came back, so I quickly turned it off again.

After letting it rest, we took the sparkplugs out, and after that I regretted not taking the sparks out sooner. One had a broken tip...and Im guessing thats probably the cause of the knock..

I am not sure of my next steps from here...and I am curious why the knock wasnt there when I started it again for 5 minutes while it was in idle

Any help appreciated
I am getting compression tested today btw

Thanks





Cyl 1 --> 4

 

cylinder 4 is covered in oil. I'd probably say its hosed. How many miles are on those plugs? The burning above the "nut" on the insulator indicates the plug has been leaking, typically from the plugs either being really old or if that happens quickly then you've been getting detonation which will loosen the porcelain from the metal.

see how #1 looks far more burnt than the other ones

 

Broken spark plug looks like detonation. Improper heat range, gapping of tip, too lean fuel mixture may have caused this.

 

That sucks.

Expect carnage

 

Carnage sounds like the right word. I have no idea how many hours it takes to pull the cylinder head on this engine.

Curious about a few things:
Model year car? Mileage?
Mileage on spark plugs?
Were the plug gaps adjusted during installation?
Valves ever adjusted?

-- Chuck

 

valves adjust 1000miles ago before this happened..
2003
95000 miles

not sure about gapping

 

Is the number one coil pack torched/black/sooty?

 

it didnt seem to be, all the packs looked similar and clean.
Il take another look tonight

 

Is the engine boosted ?, looks like detonation as the centre electrode damage is just as bad as the ground electrode damage.

 

This recently just happened with my vehicle as well. Car kept misfiring so I pulled the plug and it looked exactly like yours. Replaced the plug and all was good until a few days later I was on the hwy and CEL kicks on. Before I was able to get it off the hwy the vehicle died. Cyl3 had gotten so hot it melted the spark plug and coil together. All other cylinders are still good on compression. Still don't know what caused my malfunction. I bought new injectors along with seals, coil packs and spark plugs again. waiting to see the damage once I get the head off but if you need some extra parks lmk. I have the cool packs, injectors and spark plugs laying around