Cylinder 4 misfire wont go away! 2.4 twin CAM

MATERROCK33

MEMBER
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

FIXITMR

MECHANIC
9,990 POSTS

What about switching injectors? Have you done compression test.

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Thursday, March 8th, 2012 AT 6:59 AM

MATERROCK33

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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

MATERROCK33

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10 POSTS

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

FIXITMR

MECHANIC
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New gaskets? Or silicone it?

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Thursday, March 8th, 2012 AT 7:27 AM

WRENCHTECH

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Replace the white coil housing.

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Thursday, March 8th, 2012 AT 11:52 AM

MATERROCK33

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

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Friday, March 9th, 2012 AT 4:00 PM

MATERROCK33

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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

WRENCHTECH

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Did you replace the coil housing?

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Wednesday, March 14th, 2012 AT 7:00 PM

MATERROCK33

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

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Wednesday, March 14th, 2012 AT 7:17 PM

WRENCHTECH

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I don't see any low compression.

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Wednesday, March 14th, 2012 AT 7:25 PM

MATERROCK33

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

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Wednesday, March 14th, 2012 AT 7:38 PM

FIXITMR

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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

FIXITMR

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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

MATERROCK33

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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

MATERROCK33

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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

MATERROCK33

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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

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