[fhh02a]

hey yall

have a question... ok i know that our engines (especally Zetec) make a lot of noise in the injectors.. but my question is -- every once in awhile it sounds like it knocks--then i rev the engine --goes away and then time passes and days go by--does it again, quick knock --goes away
only time i hear it is when i have the radio off and i am in a drive through and its in the morning/cool

what i am asking is --is it normal, or should i be worried or what --sorry for a longer post

thanks for the help

 

[mustangt69]

i have the same issue....ever figure this out?

 

[whynotthinkwhynot]

Are you sure it's an internal engine knock and not the transmission or the engine simply bouncing on a mount?

We know that the clutch release bearing makes noise with the clutch engaged (pedal up) and the transmission in neutral. That sounds like a rod knock to some people. Simply pushing the clutch pedal down removes the sound.

Akin to that, the transaxle and engine can bounce around a bit on the mounts- especially the dog bone mount causing an occasional thunk or lighter knock.

Don't worry about intermittent or every once in a while types of sounds. Those aren't going to tell you anything. If you can't replicate the conditions and recreate the event, then it's not worth worrying about. That doesn't mean that you shouldn't worry about some sounds, but it does mean that you should pay attention to what's happening at the time when the sound appears. I personally just file that stuff in the back of my head, and when it shows up several times- then I start trying to replicate what causes the sound. No matter how long you work on vehicles- you'll never be able to accurately pin down causes of intermittent, every once in a while sounds or vibrations.