Misfire on cylinders one, three, and five?

2002 SATURN VUE

170,000 MILES • 3.0L • V6 • 2WD • AUTOMATIC

SCOT ALAN BRADY

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2 POSTS
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Started with misfire cylinder 2, 4, 6. Replaced spark plugs (NGK) ignition coil packs (both banks), valve cover gasket, intake manifold gasket, fuel injector on cylinder 6 and all 6 injectors o-rings replaced. 2,4,6 no longer misfire. Now I have cylinder 1, 3, 5 misfiring. Disassembly of intake manifold, specifically cover plate and injector cover internally of manifold, was done and reassembled with new sealant. Knock sensor on bank 2 was replaced and no longer have code for p0300, p0301, p0303 and p0305 is present. Compression on all 6 cylinders are within spec. What else could be wrong?

Aug 26, 2022 at 11:09 AM

JACOBANDNICKOLAS

CERTIFIED EXPERT
110,175 POSTS

Hi,

If I understand correctly, you repaired bank 2-cylinder misfires and they moved to bank 1. How long has it been since the timing belt was replaced? Have you checked fuel pressure?

Are the codes you provided the only one's present? Also, do you have a live data scan tool that we can use? If you do, check the short-term fuel trims so I have an idea of what we are dealing with as far as fuel pressure and check the timing advance signal.

Let me know.

Joe

Aug 26, 2022 at 1:43 PM

SCOT ALAN BRADY

MEMBER
2 POSTS

As far as I know the timing belt has not been replaced. Codes provided are only ones present. I don't have a live data scanner.

Aug 26, 2022 at 2:12 PM

JACOBANDNICKOLAS

CERTIFIED EXPERT
110,175 POSTS

Scot,

If it has the original belt, I have a feeling it is stretched and causing valve timing issues. The idea that all cylinders on one bank or the other misfire, the belt is my first suspect.

I attached the directions below to remove the timing belt cover. I would open it up and inspect it for damage, dry rot, cracks, and tightness.

Let me know if you are comfortable doing this.

Take care,

Joe

See pics below.

Images (Click to enlarge)

Aug 26, 2022 at 7:14 PM