I've searched here and all over for the past few hours but I think my question is unique enough to warrant a new thread.

I have a 5.4 F150 with a Kenne Bell Supercharger. It runs great - strong with no other apparent problems. I have this ticking sounds that is noticeable at idle and is coming from somewhere behind the engine. I can't hear it with the hood open and I can't hear it at high rpms, but maybe because the exhaust rumble drowns it out. It's loud enough to hear standing next to my truck. Here's the interesting thing - the ticking doesn't increase with rpms. Because of that, I can't imagine what it would be. Exhaust, pulley bearings, piston slap - all increase under load, right? It happens upon startup but even when I've driven it for 20 miles. The ONLY time it didn't tick like this is (and I kid you not) the first time I took it to the dealer. I swear it didn't tick at all. All other times it ticks. Now the dealer is 35 miles from here by highway so maybe on a long trip it stops. I just bought the truck and haven't taken any long trips with it.

One more piece of info - one side of my dual exhaust wasn't hanging properly due to a missing bracket bolt in the rear. I bolted it back up and the ticking seems faster now but still not louder or faster/slower with rpm change. Just a constant speed all the time.

I am taking it back to the dealer for more diagnostics but if anyone has any suggestions, an educated truck owner is better than a clueless one.

Thanks for any suggestions.

BTW, the truck has 44k miles on it and a brand spanking new transmission (ticking was present both before and after the transmission replacement).

Here's a sound file I made of the ticking. Please ignore the "thunks" and "pops" you hear, which is really just the microphone moving around. The ticking should be pretty noticeable:

Ticking WAV file

 

Welcome to the site!
Enjoy FTE

 

listened to it many times,to get a real feel for the sound.
sounds like a lifter, or rocker arm ticking.
Hope it ticks when you return to the dealer.
Good luck ,,,,

 

Thanks. If it is a lifter or rocker arm, is this something that could damage the engine if it goes unfixed for a while? Of course we're just getting ready to take a 1,500 mile trip to a snowy place and I need this truck.

 

that would depend on some other variyables
it may be a weak lifter, that has been that way for some time.
if it gets really loud , then am sure it could do more damage,
but if its been this way and doesn't change as best to your knowldge, it could be ok , until repaired.
could be a worn rocker, that has been that way for a time.
I my self would think that if the oil pressure is good, and everything else is working good.
then it could last for , who knows maybe ever.
Have seen a few that ticked, and no harm,
also those that wore enough to actualy come to the point where, too much looseness cause things to damage things,
this should be a call from at least a mechanic that can actualy hear the sound in person.
unles your familar enough to mechanics and believe it to be not a very bad/loud tick .
and that it is truely from the lifter /rocker arm area, and not from the lower end,.
which it didn't seem to be as listening , to the sound file you provided.
I really can't make any good /true judgment with out actualuy being there.
Good luck on your trip.

 

It sort of sounds like the fuel injectors. They will tick (this is normal). When you increase the rpm's, the sounds they make get drowned out. You can use the old screwdriver trick and find out.

 

Thanks for the suggestions everyone. Well the dealer just got done diagnostics and it turns out it's the vaccuum actuator for the Kenne Bell supercharger. Not knowing much about superchargers, they don't know if that's normal or not so I've referred it to the Kenne Bell people.

Anyone know anything about vaccuum actuators? Is this something I can just unplug and replace on my own? The dealer suggestions it's not something that will damage anything in the meantime.

Happy New Year all.