Cylinder Numbering?

[Twizzler09]

Whats the correct cylinder numbering for the 4.0 OHV?


Front

----
4 1
5 2
6 3

Is that correct?

God help me if it is, I may have found out why I've been having problems.

 

[Big Jim M]

Number one is always the frontmost cylinder.. On some engines it is on the left and others on the right.. Your numbering is what I think it should be..
Big Jim

 

[smokey]

 

[Mutant Pony]

ALL Fords use the right front cylinder as number one.

 

[Twizzler09]

Thanks.

Now comes the next question.

Whats the likelihood of damage being caused by a plug thats not seated correctly?

When I changed the plugs last year, #5 wasn't loose...but it wiggled allllll over the place with the slightest touch. The plug thats in #5 right now is in tight and doesn't move any, but the damage caused, if any, by the previous plug would still be there.

Oh yeah, I've also tracked down the miss in my engine to Cylinder #5. Ran some computer diagnostics today to verify that my replaced 02 sensors were working, and was watching the datastream. Theres a part that counts how many times the computer has read a misfire in a cylinder #5 came up like this: "Cylinder 5 Misfire Count: 4,093"

 

[Bent Bolt]

Possible that a loose plug has wallowed out the threads but the best you do short of installing a heli-coil is to just tighten it up and leave it alone. And a loose plug will cause a missfire.

 

[Big Jim M]

I would pull that plug and install a new one in it's place. I betcha it is the plug and not the threads.
Big JIm

 

[Twizzler09]

The *old* plug that I already replaced a year ago is the one that was loose/wiggly. The one that took its place is nice and snug, no movement. However the computer shows a persisting misfire on the very same cylinder.

Was wondering if there was any sort of damage a loose plug could cause to the cylinder itself or something?

 

[Big Jim M]

No, not to anything except the plug itself.. Go ahead and spend the 5 buicks and put another plug in there.. Might be the wire also. It is not unusual for a plug or a wire to go south all by itself.

By the way many of us, myself included, have had a plug unscrew and POP out of the hole at speed! Scares the hell out of the driver.. But don't hurt anything except the plug itself.
Big Jim

 

[Explorin94]

Was wondering if there was any sort of damage a loose plug could cause to the cylinder itself or something?

That could possibly burn a valve or a piston also. With the plug being that loose it could have allowed enough air to be sucked into the bore creating a hotter burn off.

 

[Twizzler09]

Could that create lasting problems, in the form of an occasional miss?

I really don't want to teardown the motor to fix it if its not nessecary.

 

[Big Jim M]

A loose plug can lose it's ground to the block causing a miss.. If you have installed another plug and it is in there TIGHT then you don't have a possible other problem..
Now when the new plug was installed if it was cracked it may run fine and miss once in a while.. OR it may never fire correctly.
If the plug screws in tightly in the head I would forget about other possible bad things that may have happened.. There are none that I can think of.
Big JIm

 

[Explorin94]

A loose plug can lose it's ground to the block causing a miss.. If you have installed another plug and it is in there TIGHT then you don't have a possible other problem..
Now when the new plug was installed if it was cracked it may run fine and miss once in a while.. OR it may never fire correctly.
If the plug screws in tightly in the head I would forget about other possible bad things that may have happened.. There are none that I can think of.
Big JIm

I should have added to mine that a burnt valve or piston would be a noticable worst case senario.

 

[Big Jim M]

Surely one would HEAR the compression stroke whistling before the intake stroke would get enough air to burn anything in the chamber..
Big Jim

 

[Twizzler09]

Actually, Big Jim, I do have a noise that sounds something like an exhaust leak, and its coming from the driver side of the motor. The same side as #5.

What are the chances that the loose plug from last year screwed up the threads or something and is allowing air to escape through the plug hole? Escaped air would also explain the miss, a rather rich mixture.