02 Camaro V6 - help diagnose misfire in #4
09-23-2013, 10:59 PM
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02 Camaro V6 - help diagnose misfire in #4 Troubleshooting help needed, please.
A couple of months ago, I replaced the plugs and wires in my Camaro. It had been running mostly OK, but was starting to tick a little, mpg was going down, and it had been a year+ since I had done it.
After I replaced them, the car still ticked a little. I had no time to look into it further and have been traveling a lot, so it wasn't as top of mind as it would have been had I been hearing it day in and day out.
On Saturday, the car started running REALLY rough, and knocking under acceleration. I limped home and have found the following:
CEL shows P304 -- misfire in #4.
I still had the plugs & wires from the most recent replacement, so I changed out the existing #4 plug for the best looking of the bunch from a couple of months ago [they looked OK, actually, and probably didn't really need replacing]. Changing the plug and wire had NO effect on the engine, and the CEL light came back on again with misfire in #4.
I replaced the coil pack that controls #1 & #4. As a test, I temporarily put that old coil pack in place of the #3 & #6 pack.
Changing the coil pack had no effect on the engine and the CEL light came back on -- but instead of throwing an error on #6 as I had hoped (because that's where I put the purportedly "bad" coil pack) it still threw the misfire on #4.
I put the original #3 & #6 coil pack in its place. No effect on the engine. CEL light still throwing on #4.
So ... if my engine continues to misfire on #4 after swapping to used (although apparently OK) plug & wire and installing a new coil pack AND the misfire didn't follow the "bad" coil pack when I moved it ... what's next?
I'm certainly willing to try putting a truly new plug & wire in, but I was working later than AutoZone was open and ... I'm afraid that it isn't the plug/wire at all.
It does go through a lot of coolant (couple of quarts every three-ish weeks) without an obvious leak anywhere.
I really, really love my car and don't want to hear that it's an engine replacement kind of issue ...
Thoughts about what I'm missing? So to speak?
2002 Camaro 3.8L V6
174k+ miles
A couple of months ago, I replaced the plugs and wires in my Camaro. It had been running mostly OK, but was starting to tick a little, mpg was going down, and it had been a year+ since I had done it.
After I replaced them, the car still ticked a little. I had no time to look into it further and have been traveling a lot, so it wasn't as top of mind as it would have been had I been hearing it day in and day out.
On Saturday, the car started running REALLY rough, and knocking under acceleration. I limped home and have found the following:
CEL shows P304 -- misfire in #4.
I still had the plugs & wires from the most recent replacement, so I changed out the existing #4 plug for the best looking of the bunch from a couple of months ago [they looked OK, actually, and probably didn't really need replacing]. Changing the plug and wire had NO effect on the engine, and the CEL light came back on again with misfire in #4.
I replaced the coil pack that controls #1 & #4. As a test, I temporarily put that old coil pack in place of the #3 & #6 pack.
Changing the coil pack had no effect on the engine and the CEL light came back on -- but instead of throwing an error on #6 as I had hoped (because that's where I put the purportedly "bad" coil pack) it still threw the misfire on #4.
I put the original #3 & #6 coil pack in its place. No effect on the engine. CEL light still throwing on #4.
So ... if my engine continues to misfire on #4 after swapping to used (although apparently OK) plug & wire and installing a new coil pack AND the misfire didn't follow the "bad" coil pack when I moved it ... what's next?
I'm certainly willing to try putting a truly new plug & wire in, but I was working later than AutoZone was open and ... I'm afraid that it isn't the plug/wire at all.
It does go through a lot of coolant (couple of quarts every three-ish weeks) without an obvious leak anywhere.
I really, really love my car and don't want to hear that it's an engine replacement kind of issue ...
Thoughts about what I'm missing? So to speak?
2002 Camaro 3.8L V6
174k+ miles
Last edited by kcindy317; 09-23-2013 at 11:08 PM.
09-23-2013, 11:23 PM
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Time to do a compression test and a leakdown test. Eating coolant isn't good, could be a leak but it could also be a head gasket.....losing compression in that cylinder would cause a misfire. Throw a gauge on it.
09-24-2013, 04:15 PM
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Troubleshooting help needed, please.
A couple of months ago, I replaced the plugs and wires in my Camaro. It had been running mostly OK, but was starting to tick a little, mpg was going down, and it had been a year+ since I had done it.
After I replaced them, the car still ticked a little. I had no time to look into it further and have been traveling a lot, so it wasn't as top of mind as it would have been had I been hearing it day in and day out.
On Saturday, the car started running REALLY rough, and knocking under acceleration. I limped home and have found the following:
CEL shows P304 -- misfire in #4.
I still had the plugs & wires from the most recent replacement, so I changed out the existing #4 plug for the best looking of the bunch from a couple of months ago [they looked OK, actually, and probably didn't really need replacing]. Changing the plug and wire had NO effect on the engine, and the CEL light came back on again with misfire in #4.
I replaced the coil pack that controls #1 & #4. As a test, I temporarily put that old coil pack in place of the #3 & #6 pack.
Changing the coil pack had no effect on the engine and the CEL light came back on -- but instead of throwing an error on #6 as I had hoped (because that's where I put the purportedly "bad" coil pack) it still threw the misfire on #4.
I put the original #3 & #6 coil pack in its place. No effect on the engine. CEL light still throwing on #4.
So ... if my engine continues to misfire on #4 after swapping to used (although apparently OK) plug & wire and installing a new coil pack AND the misfire didn't follow the "bad" coil pack when I moved it ... what's next?
I'm certainly willing to try putting a truly new plug & wire in, but I was working later than AutoZone was open and ... I'm afraid that it isn't the plug/wire at all.
It does go through a lot of coolant (couple of quarts every three-ish weeks) without an obvious leak anywhere.
I really, really love my car and don't want to hear that it's an engine replacement kind of issue ...
Thoughts about what I'm missing? So to speak?
2002 Camaro 3.8L V6
174k+ miles
A couple of months ago, I replaced the plugs and wires in my Camaro. It had been running mostly OK, but was starting to tick a little, mpg was going down, and it had been a year+ since I had done it.
After I replaced them, the car still ticked a little. I had no time to look into it further and have been traveling a lot, so it wasn't as top of mind as it would have been had I been hearing it day in and day out.
On Saturday, the car started running REALLY rough, and knocking under acceleration. I limped home and have found the following:
CEL shows P304 -- misfire in #4.
I still had the plugs & wires from the most recent replacement, so I changed out the existing #4 plug for the best looking of the bunch from a couple of months ago [they looked OK, actually, and probably didn't really need replacing]. Changing the plug and wire had NO effect on the engine, and the CEL light came back on again with misfire in #4.
I replaced the coil pack that controls #1 & #4. As a test, I temporarily put that old coil pack in place of the #3 & #6 pack.
Changing the coil pack had no effect on the engine and the CEL light came back on -- but instead of throwing an error on #6 as I had hoped (because that's where I put the purportedly "bad" coil pack) it still threw the misfire on #4.
I put the original #3 & #6 coil pack in its place. No effect on the engine. CEL light still throwing on #4.
So ... if my engine continues to misfire on #4 after swapping to used (although apparently OK) plug & wire and installing a new coil pack AND the misfire didn't follow the "bad" coil pack when I moved it ... what's next?
I'm certainly willing to try putting a truly new plug & wire in, but I was working later than AutoZone was open and ... I'm afraid that it isn't the plug/wire at all.
It does go through a lot of coolant (couple of quarts every three-ish weeks) without an obvious leak anywhere.
I really, really love my car and don't want to hear that it's an engine replacement kind of issue ...
Thoughts about what I'm missing? So to speak?
2002 Camaro 3.8L V6
174k+ miles
Have you tried swapping out injectors?
09-25-2013, 07:56 PM
#4
Teching In
try the ignition module that the coil packs mount on. that was the fix for the same issue on my 98 v6. the parts store can test it. mine showed good but i replaced it anyway and problem fixed.
