I went ahead and replaced all the fuel injectors this weekend (96 351W)with refurbs from the Lucky 7 guy on eBay who I heard about on here. While I was in there I replaced the valve cover gaskets and tightened up the rockers a bit (23ft# each).

I put it all back together and it fired right up after a bit of cranking. However I noticed after a minute it started to make a bit of a ticking sound. After another minute it got louder. It sounds like a more mechanical clicking than an exhaust leak but what do I know. I was late so I shut it off for the evening.

The next day I fired it up and really paid attention this time. It sounds great for a minute but it starts to quietly tick a bit. After two minutes the tick gets louder then levels off to just a consistent somewhat loud tick.

I have no means right now to determine where it is exactly coming from (I've heard a stethoscope or a heater hose are the ways to go about it). It sounds like it is either coming from an injector on the right (facing the engine) to the rear or the rear of the one exhaust manifold/valve cover.

Question - If it is the fuel injector ticking, wouldn't it be ticking right off the bat? Why does it wait to get a little warm before it decides to tick?

Could it be leaking from the manifold-to-injector o-ring area? They are all in tight (a little too tight IMO).

I didn't touch any of the exhaust manifold bolts on that side. Anything else I could have done to cause a small leak?

I just hate the though of ripping all this back apart after spending so much time on it...

 

So what do you think?? Do fuel injectors tick right off the bat or do they need to warm up first?

 

hate to tell u but its ur rockers loose or a broke down lifter if it sound like this



the reason u dont hear it as soon as u start it up is because the oil is still thick enough but after it warms up the oil thins out and so u hear it

oh yeah and that video was made after about 5 minutes or so of it idling if sounds louder after it gets warmer

 

+1 on checking the rockers and lifters. You'd have to have Superman hearing to notice a noisy injector.

 

That is awesome. Thanks for posting the vid. That is NOT the same tick mine is making though... maybe I'll take a quick video of mine.

Mine is a very faint metallic sounding ticking (think stopwatch) coming from either the top of the engine or the exhaust manifold/valve cover area. I haven't had time or the knowledge to pinpoint the exact location yet. It sounds like it is (2x or so) faster than the RPMs of the engine if that makes any sense. Your video seemed to tick with the normal cycles of the engine.

I was thinking it is an injector only becasue it is one of the things I replaced, with refurbs nonetheless. I saw some other thread here where some folks injectors were making ticking sounds. I tightened the rockers a bit (hardly any adjustment at all really) but I'd like to think it wouldn't be causing my ticking. I dunno...

I guess I'll have to pinpoint the exact location! I was just hoping for an opinion or two in the meantime.

 

You could unplug them one at a time and see if the noise goes away with a particular one not cycling. Just don't try to do this while the engine is running: unplug, start, check, shutdown, plug, next.

 

well i hope it is just an injector because the only other thing that could sound like that on the top end is a wrist pin :O

 

I don't think it is an injector , but i cant here what your are , exhaust leak , valve train , spark jumping , use a wood dowl or something & hold it to your ear & see if you can track the noise down ...Lew

 

mprice, you area genius. I unplugged each one on the right one at a time and it still made the noise. I tried to take a video on my phone but you couldn't hear the ticking.

I have it narrowed down to two things now: a leak in the intake where the injector sits (bad o-ring) or a leak in that black pipe that runs from the air pump. I am not sure if either are capable of making this ticking sound but you never know...

I have nothing in my posession right now I can use to better listen to it.

 

Then its more than likely the air pump tube ....