Spark plug #4 keeps going bad
Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
I agree it could be a head gasket issue, or maybe even a slightly cracked head.
There is also the possibility of a bad lower intake gasket. My experience:
https://www.ford-trucks.com/forums/2...e-gasket.html?
There is also the possibility of a bad lower intake gasket. My experience:
https://www.ford-trucks.com/forums/2...e-gasket.html?
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
OK, good feedback & idea to use the camera in #4 cyl. Bummer about finding coolant, but that wasn't unexpected, so now you have confirmation why #4 spark plug has been giving up the ghost. Now the question is it the head gasket, or head casting???? Let us know what you find.
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Junior User
Joined: Jul 2015
Posts: 79
Likes: 0
From: Shippensburg, PA
OK, good feedback & idea to use the camera in #4 cyl. Bummer about finding coolant, but that wasn't unexpected, so now you have confirmation why #4 spark plug has been giving up the ghost. Now the question is it the head gasket, or head casting???? Let us know what you find.
Fleet Mechanic
Joined: Sep 2007
Posts: 1,726
Likes: 10
From: down south
I cant remember the name right now, national cylinder head exchange?....maybe? Out of TX. $300 for rebuilt heads to your door and then send them yours back. not a bad deal. They had the new ones to my doorstep on thurs after ordering on monday.
Thats not it...let me look them up.
Cylinder heads international.
http://www.headsonly.com/index.htm
Thats not it...let me look them up.
Cylinder heads international.
http://www.headsonly.com/index.htm
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
Before you jump to conclusions about it being a head casting problem, has a blow down test been performed?
EDIT: If you get a positive on other cylinders with the blow down test, it would suggest a head gasket problem, rather than a head problem, as its unlikely that all cylinders would have a crack in the head there. Has the coolant always been changed on time such that its always been in good condition, without rust???
EDIT: If you get a positive on other cylinders with the blow down test, it would suggest a head gasket problem, rather than a head problem, as its unlikely that all cylinders would have a crack in the head there. Has the coolant always been changed on time such that its always been in good condition, without rust???
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Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
If you go with new heads you will need them specific to the '98+ Ford 4.0L OHV.
See: Rebuilding The Ford 4.0L Pushrod V6, Doug Anderson, Automotive Rebuilder, April 2001
Another 4.0L head-related thread that might help: Serious Explorations- 98 Exp 4.0 OHV Coolant Loss/leak, Misfire, Cylinder Head Advice
If you do decide to replace the heads, keeps us posted on your progress.
See: Rebuilding The Ford 4.0L Pushrod V6, Doug Anderson, Automotive Rebuilder, April 2001
Another 4.0L head-related thread that might help: Serious Explorations- 98 Exp 4.0 OHV Coolant Loss/leak, Misfire, Cylinder Head Advice
If you do decide to replace the heads, keeps us posted on your progress.
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Junior User
Joined: Jul 2015
Posts: 79
Likes: 0
From: Shippensburg, PA
Before you jump to conclusions about it being a head casting problem, has a blow down test been performed?
EDIT: If you get a positive on other cylinders with the blow down test, it would suggest a head gasket problem, rather than a head problem, as its unlikely that all cylinders would have a crack in the head there. Has the coolant always been changed on time such that its always been in good condition, without rust???
EDIT: If you get a positive on other cylinders with the blow down test, it would suggest a head gasket problem, rather than a head problem, as its unlikely that all cylinders would have a crack in the head there. Has the coolant always been changed on time such that its always been in good condition, without rust???
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Junior User
Joined: Jul 2015
Posts: 79
Likes: 0
From: Shippensburg, PA
Not sure what route i want to take yet. I would like to rebuild all of the top end. If it turns out to be just the gasket i would still like to have the heads checked and milled and to have that done would cost just as much if not more than new ones. So why not just go with new ones that are stronger than the oem ones? Just bought a house so extra money will be tight for a while till we get settled.
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