Cylinder 4 misfire wont go away! 2.4 twin CAM

Tiny
MATERROCK33
  • 2001 PONTIAC GRAND AM
  • 164 MILES

Always cylinder 4. Replaced spark plugs, boots, coil packs, tested injectors and everything is fine. Tried flipping the coil packs and tried switching plugs around, the miss stays on 4. There is also a lot of oil leaked and pooled in by the plugs. Any ideas?

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Thursday, March 8th, 2012 AT 6:19 AM

17 Replies

Tiny
FIXITMR
  • MEMBER

What about switching injectors? Have you done compression test.

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Thursday, March 8th, 2012 AT 6:59 AM
Tiny
MATERROCK33
  • MEMBER

Was told because injectors ohmed out fine, it wouldn't make a difference to move them. Should I still try it?

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Thursday, March 8th, 2012 AT 7:03 AM
Tiny
MATERROCK33
  • MEMBER

For the oil in there, do I need to replace the valve cover/cam cover? Or is there a simpler or easier reason and way to fix?

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Thursday, March 8th, 2012 AT 7:08 AM
Tiny
FIXITMR
  • MEMBER

New gaskets? Or silicone it?

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Thursday, March 8th, 2012 AT 7:27 AM
Tiny
WRENCHTECH
  • EXPERT
  • 20,807 POSTS

Replace the white coil housing.

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Thursday, March 8th, 2012 AT 11:52 AM
Tiny
MATERROCK33
  • MEMBER

Thanks, I'll try that & let you know.

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Friday, March 9th, 2012 AT 4:00 PM
Tiny
MATERROCK33
  • MEMBER

Did a compression test. 160 on cylinders 1 and 4 and around 170-172 cylinders 2 and 3. Still only mifiring on 4.

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Wednesday, March 14th, 2012 AT 12:36 AM
Tiny
WRENCHTECH
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Did you replace the coil housing?

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Wednesday, March 14th, 2012 AT 7:00 PM
Tiny
MATERROCK33
  • MEMBER

Yes. But how is that related to the low compression?

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Wednesday, March 14th, 2012 AT 7:17 PM
Tiny
WRENCHTECH
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I don't see any low compression.

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Wednesday, March 14th, 2012 AT 7:25 PM
Tiny
MATERROCK33
  • MEMBER

It's ok that there's 10psi difference?

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Wednesday, March 14th, 2012 AT 7:38 PM
Tiny
FIXITMR
  • MEMBER

On these motors I have seen blown head gaskets between adjacent cylinders. If you keep driving it. It should get worse.

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Thursday, March 15th, 2012 AT 5:13 PM
Tiny
FIXITMR
  • MEMBER

Oops. Dont look like your adjacent cylinders are mixing. I read it wrong.

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Thursday, March 15th, 2012 AT 6:29 PM
Tiny
MATERROCK33
  • MEMBER

No additional repairs have been made but driving down the road today my CEL turned off. Fluke?

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Friday, March 16th, 2012 AT 1:18 AM
Tiny
MATERROCK33
  • MEMBER

Must have been because it came back on today! I'm really at a loss of words with this car.

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Friday, March 16th, 2012 AT 3:39 PM
Tiny
MATERROCK33
  • MEMBER

Ok guys, I've replaced everything. Plugs, boots, coil packs, housing and now a fuel filter. It started without a miss but it's back again! I'm running out of things to change. Any other ideas?

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Sunday, March 18th, 2012 AT 4:37 AM
Tiny
WRENCHTECH
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Following this thread it doesn't appear you have ever tried replacing or moving the injectors. If you can isolate which cylinder is missing, then the injectors are what you should be looking at now.

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Sunday, March 18th, 2012 AT 11:59 AM

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