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- '02 Mazda Protege5
Could it be a leaking head gasket causing a loss of compression or coolant fouling plugs of something?
Help with Misfire / Stuttering
- Thread starter HazardLevel5
- Start date
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- -- 03 P5 / 23 CX-5 --
Burning extra oil might foul them. Are they gak'd up with carbon bad or just around the threads a little? Could be coil packs or plug wires with or without codes. NGK copper would be the best bet for plugs. I used the NGK iridiums once but they did nothing to improve things but have heard stories about platinums & other trick garbage plugs messing with the motor/ecu. Just bkr5's or zfr5's (long reach) are best. Also as was stated, check your air intake rubber hosery to throttle body for cracks. MAF clean or been cleaned? Check that. EGR shouldn't cause misfires but will screw with idle. If head gasket your oil & antifreeze would be leaking somewhere, smoking of either or both types if bad enough & oil/water would be sharing each other's overflow tank or pan. Check your fluids to be sure they aren't mixed. That takes us to injector cloggage and/or fuel delivery issue with strainer or pump itself. Have seen threads where pump was working but weak & caused misfires IIRC. Maybe bad ground or weak alternator not powering plugs enough, stretching now. Other than that, maybe cam position sensor or crank sensor starting to fail??? Cover all the easy cheaper stuff & eliminate as much as possible. Good luck & let us know what it is when you conquer.
I highly doubt that this is the problem, but since misfiring is a timing issue, and since the timing is electronic- you might take a look at the crank position sensor and the crank pulley (which if stock- has the crank timing gear attached to it). If there was a problem here- you'd likely be running very bad, or not at all- but it only takes a second to look it over...
Everyone has so far missed the obvious. He is only getting a misfire in the number 3 cylinder. This rules out things such as a clogged fuel filter, bad coil packs (which, 3 people have told him to replace even tho he said that he did so in his first post (smash)), etc. which would cause a P0300, or random misfire, code.
The only things that can cause a misfire in only one cylinder are:
1. Bad spark plug wire (probably)
2. Bad fuel injector (a stretch, but possible)
3. Intake air leak near the No. 3 cylinder (around the intake manifold, not the intake air boot - doubt it).
4. Poor engine compression in the No. 3 cylinder (doubt it).
5. Electrical malfunction (doubt it)
Replace your spark plug wires and your problem should be fixed. Sometimes they can test good but still perform poorly under heavy load. This is actually almost a textbook case of bad spark plug wires.
The only things that can cause a misfire in only one cylinder are:
1. Bad spark plug wire (probably)
2. Bad fuel injector (a stretch, but possible)
3. Intake air leak near the No. 3 cylinder (around the intake manifold, not the intake air boot - doubt it).
4. Poor engine compression in the No. 3 cylinder (doubt it).
5. Electrical malfunction (doubt it)
Replace your spark plug wires and your problem should be fixed. Sometimes they can test good but still perform poorly under heavy load. This is actually almost a textbook case of bad spark plug wires.
