First let me say, I LOVE MY TRUCK! - if you don't know or have forgot - 1999 XLT 4.2L 117k silver scab

But what the heck? I got my truck back today after a new universal cat, front & rear brakes, oil change and tire rotation. I am now hear a click or tick (my best way to describe). Definately not the deep throat (wow, no pun intended!) of a hole in the exaust. More throttle, faster tick. No tick at idle. Maybe it was already there and I just couldn't hear it over the "spoon stuck in the garbage disposal" sound? I got under the truck and it is NOT coming from there. So I got under the hood and it sounds like its the block or near to it. It does not seem to be a fan, but I have been known to be wrong.
Remember, I can do a limited amount on my truck and can't afford to run back to the mechanic - so start me out with the easy stuff to check, K?
Or maybe I should just get a FlowMaster so I can't hear anything else? If I can't hear it, it isn't be broken right?

 

Sounds like the beginnings of an exhaust leak. My 4.9 has a nasty crack in the manifold, which doesn't emmit a deep roar, but a rather sharp tick. I thought it was valves going, but when I did my calipers and such, I saw the crack. You could have the exhaust gasket going, or a crack developing in a manifold.

 

On my '96 150 I picked up a ticking noise- better described as a "popping" sound to the rear of the engine, up against the firewall. Took it to a buddy of mine, and it turned out to be a "bypass tube" (I think) that either is fed from the oxygen pump, or vise-versa. It is welded into the back of the exhaust manifold, and not a big deal to fix (for me, about 70.00). Now that was on a 5.0 (or 4.9 for the purists) 302 . Your 6 may have a similar system. Not a ford repair though, if you've got a good mechanic you can dodge the high repair cost. Good luck!! When ya coming to the Cape???

 

I thought my tick was an exhaust leak.. then a few weeks later my truck spit #3 plug. 1998 4.6L. Turned out to be about a $1500 dollar tick.

 

could also be your injectors.

 

You would know the sound better, but 2 people have said at idle the it sounded like a leak starting, so of like a gasket. Is that the case with what you heard as well ?

Singlemom,
Is the ticking sound kind of like the GM lifter noice from years gone by ( i.e. A '76 Pontiac V-8 ) when you drive , or more of a ticking noise in the cab, but out the window it is still kind of quiet ?

 

Hi guys,

My tick is the Cat. I've been under the hood and under the truck and it is definately coming from the new part. I think it is leaking and the guys at my work who will help me, say it is leaking. The mechanic says it is normal and will not fix it.
I'll hang on to the receipt from the mechanic. I am due for the emmissions check in December. They won't pass me if it is leaking and the mechanic will have to fix it - or get sued - it will be up to him. I don't see that there is much else I can do until then. Since I already put $1k into it in the past 2 weeks and $200 for a rental car - I am tapped out. Can't afford a second opinion.