Startup Pre-ignition

[SCRider]

My '08 makes the same knocking sound a few times as well when first started. Pull the clutch in and see if it still makes the noise, mine doesn't. I believe it's just the engine missing and the noise is coming from the backlash in the tranny gears bouncing off one another. Someone else mentioned a while back that they had a hard knocking noise if you blip the throttle when cold. Again, mine does this when in neutral with the clutch engaged but doesn't if you pull the clutch in. Had a very similar knocking noise on an SVT Focus after I put an aluminum flywheel on it. The pulses from the individual cylinders firing would rattle the gears in neutral because the flywheel was tool light to absorb the pulses.

SCRider

 

[skifrik]

My 06 AE does the same thing and when I has doing a TBS, I noticed that the vaccum on the #4 cyl would go to zero when it would happen. I was wondering if it was a sticking valve, or something like that.

 

[Jimstan]

2007 same thing, sounds much more like a missing cylinder than anything else

As temp. increases it lessens until full operating temp. It also seems to be only in one cylinder.

I would like to know the cause so I can fix it so off to the dealer we go.

Jimstan and Zeus

 

[Rondo777]

2007 same thing, sounds much more like a missing cylinder than anything elseAs temp. increases it lessens until full operating temp. It also seems to be only in one cylinder.

I would like to know the cause so I can fix it so off to the dealer we go.

Jimstan and Zeus

Ill say it one more time just in case you missed the first 2 times, :headbonk: change your plugs, I know they may be brand new, so were mine, just change them. Iridium worked for me.

 

[Jimstan]

2007 same thing, sounds much more like a missing cylinder than anything elseAs temp. increases it lessens until full operating temp. It also seems to be only in one cylinder.

I would like to know the cause so I can fix it so off to the dealer we go.

Jimstan and Zeus

Ill say it one more time just in case you missed the first 2 times, :headbonk: change your plugs, I know they may be brand new, so were mine, just change them. Iridium worked for me.

OK OK...... I will change my dam plugs, Dear...... I mean Rondo777

Jimstan

 

[spineman]

2007 same thing, sounds much more like a missing cylinder than anything elseAs temp. increases it lessens until full operating temp. It also seems to be only in one cylinder.

I would like to know the cause so I can fix it so off to the dealer we go.

Jimstan and Zeus

Ill say it one more time just in case you missed the first 2 times, :headbonk: change your plugs, I know they may be brand new, so were mine, just change them. Iridium worked for me.

OK OK...... I will change my dam plugs, Dear...... I mean Rondo777

Jimstan

So did it work Jimstan?

Mine too. Glad I found this thread. Just didn't sound right to me!

 

[KnuckleHead]

Mine doesnt do this. I even went out and started it cold just now in case I have just gotten used to it. But, nope.

Does anyone that is experiencing this have a PCIII? I have one...maybe that is the difference?