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Help! Cylinder 3 Misfire.

  • Thread starter Thread starter Birdhouse
  • Start date Start date Sep 9, 2013

Birdhouse

New Member
Sep 9, 2013
4
0
2
Brandon, Mississippi
Sep 9, 2013
#1
  • Sep 9, 2013
  • #1
Hey all,
My 02 GT 4.6 5 speed is giving me a few issues. Rough idle, sputtering through all rpms and substantial loss of power. Only addons are a magnaflow exhaust system with offroad H pipe, no cats and a cold air intake. CEL is on and it's pulling a missfire in cylinder 3 code. These are the things I've tried so far:
-plugs
-moved around coils and injectors
-cleaned MAF, IAC, PCV and throttle body
-replaced alternator
-visually checked hoses for damage.

After doing all this, I reset the CEL each time only for it to return 20 or so miles later with the same code. When I was changing the plugs, I did notice some coolant in plug wells 7 and 8 but I'm not getting any codes for those cylinders. I inspected the intake manifold and didn't see any cracks in it but I know they're prone to cracking. I went ahead and ordered a new one from American Muscle and it should be in tomorrow. I have noticed a slight tapping on the passenger side under the engine. It's hard to explain but I can even here it when I'm driving underneath the passenger floorboard. I researched that and think it may be an exhaust leak? It looks like it's dripping water on the passenger side where the exhaust turns up to go towards the engine.
The only other thing I can think of is maybe a short in the engine harness that goes to cylinder 3 coil maybe? Just trying to exhaust my resources before I actually have to go into the motor and check out the cylinder. Any help is greatly appreciated!!
 

trinity_gt

10 Year Member
Jan 31, 2003
3,125
81
99
Canada
Sep 9, 2013
#2
  • Sep 9, 2013
  • #2
Compression test would be my next move.
 
Reactions: trombonedemon

joshjwc9

Active Member
Jun 12, 2006
1,095
17
39
Palm Harbor, FL
Sep 9, 2013
#3
  • Sep 9, 2013
  • #3
There is a way to do a pin out test to see what kind of resistance each coil is getting but you'd have to do a search as I have no clue where you'd begin. @wmburns
 

Birdhouse

New Member
Sep 9, 2013
4
0
2
Brandon, Mississippi
Sep 14, 2013
#4
  • Sep 14, 2013
  • #4
Did a compression test today. All cylinders were around 95ish except 3, which was at 30. Is it possible to pull the head with the motor still in?
 

trinity_gt

10 Year Member
Jan 31, 2003
3,125
81
99
Canada
Sep 14, 2013
#5
  • Sep 14, 2013
  • #5
Birdhouse said:
Did a compression test today. All cylinders were around 95ish except 3, which was at 30. Is it possible to pull the head with the motor still in?
Click to expand...

Yes.
 
Reactions: Birdhouse

Birdhouse

New Member
Sep 9, 2013
4
0
2
Brandon, Mississippi
Sep 14, 2013
#6
  • Sep 14, 2013
  • #6
Ok great. Thanks for the help!
 
F

ForgedBlack01gt

Member
Nov 19, 2004
33
0
7
San Jose, Ca
Nov 10, 2013
#7
  • Nov 10, 2013
  • #7
check heater hose line... might be leaking under high pressure to drop coolant into that bank... your coils in any wet cylinders probably need replaced (just did on my stang)
 
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