Hi everybody! This is my first post.

I just purchased an '00 AP1 a month ago with 88k mi, beautifully maintained by the dealer with all recalls done, records, blah blah... and a few days later it began to act up on me.

I was driving to work and suddenly when i stepped on the clutch to downshift gears to slow down for the car in front of me, the idle drops and the car shuts down on me! so i pull over and try to restart the car. it wouldnt turn over so i tried again and stepped on the throttle a little, and then the car started and began to shake like crazy. the CEL came on and then the rough idle began.

i did not mechanically over-revv the car and i only tried vtec once..so i thought it cant be a bent valve. we pulled the codes and it was showing a misfire in cyl 1-4 and a random misfire. so we did a compression test and while taking out the plugs, we noticed the plugs werent torqued to specs - it was hand tight! then after the test it showed cly 2 had low compression (210, 183, 210, 210). and then did the test again a few weeks later and it was 194, 187, 191, 190. we were going to do a leak down test but we lost our gauge

i changed the plugs out to iridiums and torqued it to 18lbs. to see if it was the plugs but the CEL still came back on. but i noticed the idle to be a lot smoother. the CEL blinks only when i first start and the car runs 'fine' when i drive. the car IS surprisingly drivable and no knocks or anything coming from the engine. i know the car is trying to tell me something but with little knowledge i have about this motor i dont know whats next.

id like to know from you guys in the s2k community, from your experience, what this might be and what steps i should take next before i actually throw down and replace/rebuild the head.

sorry for the long post!

 

did you pull the code?

 

We can guess at what codes you got by your description, but you should specify what they are.

What are the current conditions for the misfire? Is it only at idle? If at idle, is there puffing out the exhaust that can be associated with a miss?

 

yes it was:
P0300 Random Misfire
P0301 No. 1 Cylinder Misfire
P0302 No. 2 Cylinder Misfire
P0303 No. 3 Cylinder Misfire
P0304 No. 4 Cylinder Misfire

 

thanks for the replies!
there is no puffs coming from the exhaust when warm. but only in the morning when i start i notice white puffs. thats it.

 

Can you detect (hear/feel) when the misfires are happening? Under what specific conditions (cold/hot, idle, under load while accelerating, etc) now that the plugs are changed?

When the codes return after reset do they all come back at the same time? I would do a reset then upon first noticing the CEL read out the codes to see.

Some causes of misfire, others can chime in to add to this...

• Bad gasoline
• Dirty fuel injectors (lean misfire)
• Coil packs (not likely since you have all four misfiring)
• Worn spark plugs (you changed these already)
• Bent valves (check with compression leak down)
• Bad ECU (have heard of one case)
• Coolent leak into manifold or cylinder (water in oil? coolant low over time?)

One thing you mentioned was loose plugs, were all loose, which ones? Are the ends of your coil packs okay on the cylinders with loose plugs? Other cases of loose plugs melt the end of the coil pack where it connects to the plug.

 

thanks for the info, random1. the loose plugs were on #2 and #3 and were retighted to specs when we found out but swapped the whole set for some new iridiums.
during idle, the car begins to have a mildly rough idle...but during acceleration, the car runs/drives normal. just during idle the car feels like it misfires.
when we pulled the old plugs, they showed normal wear and the coilpacks were not damaged (we even swapped them around).
after reset, the codes came back at once after a 20 min drive.

(i know its hard to give me a straight answer since you guys cant physically see whats wrong with the car, and ive read a lot about misfires on this forum. but i didnt seem to find a post that was similar to my case.)
your replies are helping me understand this problem more. thanks again!

 

welcome the S club, i thought the CEL was normal.

 

Try running fuel injector cleaner (Redline or Berryman) through a tank of gas and see if it makes any difference (good or bad). Sometimes this makes the engine run worse.

At this point you'll just have to do a process of elimination.

 

thanks all, i will try all avenues and post my findings when i find out whats wrong.