engine knock in my 4.6
10-02-2005, 07:12 PM
#1
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engine knock in my 4.6
need help really bad my 00 mustang gt 4.6 sohc has a unusual knock coming from the pasenger side valve cover area . i need to know if it could be a lifter or more serious only makes a noise when engine is somewhat cool and a load is on the car
10-02-2005, 07:34 PM
#2
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RE: engine knock in my 4.6
I had a similar problem with one of my engines, but the noise was all the time. The intake valve was sticking a little, and this allowed a little extra movement for the rocker arm. If I revved the engine high enough, the rocker arm would fall off. Just to be safe, I would take it easy for a while until it gets fixed.
10-02-2005, 09:03 PM
#3
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RE: engine knock in my 4.6
We just took apart a 2V not to long ago after being told it had a cracked piston. Come to find out (just like I had suggested to begin with) that it was a floated valve and one of the #1 cyl rocker arms was laying in the bottom of the head. Take the passenger valve cover off and take a look. If everything is okay then look under the drivers side. ***NOTE: The drivers side valve cover probably wont come off without lifting the passenger side of the engine because of the brake booster jars it in!***
10-03-2005, 12:33 AM
#6
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RE: engine knock in my 4.6
It only does this when the engine is cold?It could be a foreign object blocking the orifice in the lifter causing it to only partially fill when cold.As you know,cold oil doesn't flow as well as hot oil.I think you can run Sea Foam in the oil.I'd try this and see if it helps before tearing into the engine.If it don't help then your'e going to have to get the tools out.Use a long screwdriver or a wooden dowel to try and isolate which lifter it might be so you don't have to pull all of them to find the bad one.If the sound seems to be coming from the top of the valve cover it's probably a lifter,from the bottom,well thats where the valves live.
10-03-2005, 09:35 PM
#7
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RE: engine knock in my 4.6
ORIGINAL: black00thunder
the engine only does this around 2500/3000 rpms but goes away in higher rpm should i check the valves and what do i do if the valve is floated i dont understand
the engine only does this around 2500/3000 rpms but goes away in higher rpm should i check the valves and what do i do if the valve is floated i dont understand
Let me know if/when you figure it out.
10-04-2005, 10:06 PM
#8
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RE: engine knock in my 4.6
Well the car is at Ford now - gave up on what to do. Seem to think its the right-side lifters. Doesn't make any noise at idle, but when reved to about 1700 rpms, it starts to tap and as the rpms get higher it goes away. The tapping isn't consistant and sometimes it doesn't do it at all. Everyone kept saying lifters ... well I guess we'll find out. I'll keep you guys posted.
10-04-2005, 11:16 PM
#9
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RE: engine knock in my 4.6
ORIGINAL: black00thunder
Well the car is at Ford now - gave up on what to do. Seem to think its the right-side lifters. Doesn't make any noise at idle, but when reved to about 1700 rpms, it starts to tap and as the rpms get higher it goes away. The tapping isn't consistant and sometimes it doesn't do it at all. Everyone kept saying lifters ... well I guess we'll find out. I'll keep you guys posted.
Well the car is at Ford now - gave up on what to do. Seem to think its the right-side lifters. Doesn't make any noise at idle, but when reved to about 1700 rpms, it starts to tap and as the rpms get higher it goes away. The tapping isn't consistant and sometimes it doesn't do it at all. Everyone kept saying lifters ... well I guess we'll find out. I'll keep you guys posted.
10-05-2005, 11:48 AM
#10
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RE: engine knock in my 4.6
The dealership called this morning - they didn't change the lifters because now they seem to think I need a new head on the passenger side. They said I could drive the car and it wouldn't mess anything up internally. This noise seems to be a mystery to everyone. Who knows. I still may have someone replace the lifters since that was the initial thought of what was wrong. If anyone has any thoughts or had this happen, please let me know.