Found my shaking/bad running problem...bad engine :(
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Junior User
Joined: May 2007
Posts: 53
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From: Ithaca, NY
Found my shaking/bad running problem...bad engine :(
So if you were following my issues in my other thread, I'm not to excited to say I think my engine is junk...
I dont think its worn cam lobes....
Cylinder#
4. 70psi 8. 20psi
3. 60psi 7. 155psi
2. 110psi 6. 150psi
1. 110psi 5.150psi
So all the plugs looked "normal" (maybe slightly fouled) expcept for #8 which had oil on the plug... I added oil to the cylinder and it didnt build pressure either....
What do I do now?
The trucks got got 128k miles 1998 4.6L
a bad anti-skid control valve, prolly have to replace the lines too
Needs egr tube
and whatever the head job is going to take
I have NEVER gotten to drive it because it was always running bad... 6months later I find out its junk this really really sucks!
-Brad
I dont think its worn cam lobes....
Cylinder#
4. 70psi 8. 20psi
3. 60psi 7. 155psi
2. 110psi 6. 150psi
1. 110psi 5.150psi
So all the plugs looked "normal" (maybe slightly fouled) expcept for #8 which had oil on the plug... I added oil to the cylinder and it didnt build pressure either....
What do I do now?
The trucks got got 128k miles 1998 4.6L
a bad anti-skid control valve, prolly have to replace the lines too
Needs egr tube
and whatever the head job is going to take
I have NEVER gotten to drive it because it was always running bad... 6months later I find out its junk this really really sucks!
-Brad
New User
Joined: Feb 2006
Posts: 18
Likes: 0
Those compression tests are very interesting. Three have low psi and they are not all on the same head. Normally I would say with low compression i'd check: head gaskets, stuck valves, or rings. But with it on being on both sides and three of them, who knows. Probably not the rings if you added oil with no gain in psi. Has the truck been severely over heated? Maybe both your head gaskets went.
Last edited by winsorcoke; Jan 15, 2008 at 12:18 PM.
Elder User
Joined: Aug 2006
Posts: 642
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From: Olathe, KS
one step further on winsorcoke comments. A leak down or air to the cylinder may help to isolate the big leaks. I would expect 20 psi to be valves. A head gasket should be heard for that size leak. (been wrong before) The air might help figure if the lower end is salvageable or better left to be rebuilt. Hopefully you have the funds to replace the engine and won't have to patch it up.
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
llike the other guys, i see no common ground between these 3 cylinders. i believe the motor got very hot at one time, and you have big problems. start up with the oil cap off, do you have a lot or pressure out the cap?
More Turbo
Joined: Dec 2002
Posts: 743
Likes: 2
From: MI -- farmboy
i had a 99 4.6 with head gasket problems. It started using antifreeze and was leaving yogurt on the filler cap. I caught it just in time and traded it in. I kinda feel bad sticking somebody else with the problem, but I was not about to stick another dollar into that piece of crap truck.
I guess the point I am getting at here is that it most likely was just head gaskets, as from what I heard, this was rather common in the late 90's modular engines.
I guess the point I am getting at here is that it most likely was just head gaskets, as from what I heard, this was rather common in the late 90's modular engines.
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Elder User
Joined: May 2004
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From: sanford
Take your valve covers off and let us now how many rocker arms are laying next to the valves.I would say windsorcoke is the closest
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Thread Starter
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Junior User
Joined: May 2007
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From: Ithaca, NY
Chaser and LXman,
I'm not following either of you guys...
So remove the valve covers and check for broken rocker arms? I'm a toyota tech we dont touch things like this... I'm lost on the terminology of "Gaulding" as well...
I'm not following either of you guys...
So remove the valve covers and check for broken rocker arms? I'm a toyota tech we dont touch things like this... I'm lost on the terminology of "Gaulding" as well...
Moderator
Joined: Dec 2001
Posts: 22,436
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From: Louisville,Ky.
Lack of oil causing them to get burrs on the valve stem and not letting them close completely.
It has cam followers, lick rocker arms, but no pushrods. They are over a hydraulic lash adjuster (looks like the end of a pushrod) on one end, and are over the valve on the other end with a roller in the middle that follows the cam lobe to open the valve. The end over the valve has sides that drop over the valve enough to keep it lined up. Sometimes after an engine has sat a long time, the lash adjusters bleed off and when started, the followers can jump out of place and fall off. I would remove a valve cover and see if you have any parts laying in the head. They go back in pretty easy.
Here is a pic of the cam followers without the camshaft over them. https://www.ford-trucks.com/user_gal...140266&width=2
It has cam followers, lick rocker arms, but no pushrods. They are over a hydraulic lash adjuster (looks like the end of a pushrod) on one end, and are over the valve on the other end with a roller in the middle that follows the cam lobe to open the valve. The end over the valve has sides that drop over the valve enough to keep it lined up. Sometimes after an engine has sat a long time, the lash adjusters bleed off and when started, the followers can jump out of place and fall off. I would remove a valve cover and see if you have any parts laying in the head. They go back in pretty easy.
Here is a pic of the cam followers without the camshaft over them. https://www.ford-trucks.com/user_gal...140266&width=2
Last edited by LxMan1; Jan 16, 2008 at 12:16 PM.
Elder User
Joined: May 2004
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From: sanford
While you have the valve cover off,If you find the rockers laying in there,It would be easier to reinstall them with the cam journal top removed(Loosened). Before you go any farther pull those off and see if there is any gauling in there also.If there is any dont waste any more of your time.If not it would be a good idea at this time to replace the lash adjusters at this time
