Cylinder misfire after replacing spark plugs

Hi Tacoma World!

I'm a pretty new Tacoma owner. I bought an 04 prerunner 4 cyl 2.7 liter about 6 months ago. It has been a dream ever since and because I love it so much, I try to do all the maintenance myself. Oil change, replaced the accessory belts and spark plugs. I am learning as I go and it's been fun.

Here's my problem and I've got a feeling I'm doomed:

A few months ago I got a P0303 (misfire in cylinder 3). I pulled out what I though was 3 (third one from the driver's seat) and this is what the ignition coil looked like (left):



So I replaced it along with all new NGK iridium spark plugs. Problem solved... For a few months. A few weeks ago, I got the same code again. Didn't have time to get to pulling everything out again until today. The ignition coils were fine. However, the second cylinder from the driver's seat looked like this:



Lots of gunk and looks like it had been torched. So I switched spark plugs 2 and 3 and cleared the code and now just gonna wait to see what happens.

I'm worried because, when checking all my fluids I noticed my antifreeze was almost empty. Prior to moving closer to work (Jan. 1st), I was driving about 400 miles a week so I'm not sure if this could be the reason (still learning guys). I know these combination of symptoms could mean a cracked head which is something I just can't afford to fix right now.

I want to get your input before I take it to the mechanic and get charged 100 bucks just to tell me what's wrong.

Any and all input would be greatly appreciated! Cheers!

 

hows the oil? Meaning have you been adding oil? Blue smoke is typically oil, white smoke can mean steam/coolant. Oil on the spark plug may be just dripping off the top somewhere or a different problem is leaky valve seals/rings etc. If you are losing coolant look for leaks external of the engine, white smoke for head gasket, and or coolant in the oil or oil in the coolant etc. compression check may give you a clue to which piston is problem.

Misfire code also can be caused by plug wire not all the way seated but can be other problems.

 

I haven't had to top off any oil since I got the truck. Been changing it every 3k (been reading up, it may not be necessary to change every 3k with synthetic oil?). No fluids on the ground, unless the skid plate is catching whatever fluid is leaking. From what I can see, I am getting some smoke out of the exhaust-- looks white, but it seemed like the normal amount of smoke that would come out of any older car, but I was probably wrong about that. Not sure if there's any coolant in the oil but the last 3k I changed, the oil looked fine (very dark brown and relatively viscous to new oil, ok?). I'll probably change at the next 3k again just to be sure.

Do I need to take it in for a compression check? I doubt I have the proper equipment for that.

Would a mis-seated plug wire be a possibility even though I can feel it misfiring (rumbling) when I start the engine?

 

P.S. If anybody is located in LA/Sherman Oaks area and can help or recommend a reputable mechanic, that'd be incredible! Lunch? Beer? lol