I have a 94 F-150 with a 351 in it, as you can figure out by my name. (Yeah, I know it's pretty original) Anyways, I have noticed a ticking sound coming from the front while driving. It really only shows up when under a slight load and get a little bit deeper and noticable as I accelerate. Whatever it is will tick when cruising, but mostly only when I go up hill or like I said, under a slight load. The engine only has 43,000 miles on it, with no mechanical problems, and everything is completely stock except for the usual maintenance (oil filters, brakes, air filter) obviously. I have heard that Fords are known to sometimes have loud fuel injectors, but was wondering if anybody has any ideas. I have read the recent ticking threads with ticking on 302's, but not anything on 351's and am not sure if it's the same problem.

Thanks

 

My truck (96 4.9L) had a problem similar to the symptoms that you have said. At about 80k my exhaust manifold worped and got a leak(and it's not abnormal to happen sometime or another on these 4.9L's)It was a ticking noise but I heard it at idle and under loads. But we don't have the same engine but your problem does sound like a exhaust leak.Maybe at the headers?

BTW nice job with keeping your miles that low for that year.
I've got 114000 on my 96

 

I have a 94 w/351 and it makes a light ticking sound. A friend of mine with a lot more experience w/Fords listened and told me it was the injectors. Mine isn't as noticeable as yours but if you pop the hood and listen you can hear it.

43k on a 94, I have 87k now. It's in great shape but I need to replace some vacuum hose, starting to crack in places.

 

Thanks A Lot Guys,

I can hear ticking under the hood if I open the hood up under idle, but at idle inside the cab I cannot hear ticking. Light acceleration going down hill or on flat surface I can't hear it, but as soon as it gets more load it becomes more and more noticeable until it hits a plateau. It doesn't seem so speed up with the engine rpm, just gets a little louder as there is more gas applied or a load. Now it seems I'm convinced it's the injectors, for some reason it just doesn't sound like an exhaust leak.

 

do you know what a noisy lifter sounds like? that could very well be your case. i used to have that problem, and i took the advice of one of the mechanics on this board (PKRWUD) and i put in some slick 50 in my truck when i changed the oil and wentto a slightly heqavier oil at the same time and it took care of my problem. the noise could even be a bent pushrod or loose rocker arm, but loose lifters and exhaust leaks are the most common answers to ticking engines. good luck!

 

Just to be safe, I'd go get yourself a 3 foot long piece of heater hose, and use it like a stethescope. Put one end near an injector, and the other to your ear, and rev the engine. Try each injector. If they don't seem to coincide with the ticking you hear, try moving the hose end from the injectors to the exhaust manifolds, especially where they meet the heads. If you find a spot where the noise gets louder, investigate.

You should not be able to hear your injectors inside the truck under any circumstances, while driving.

If you determine that it's not the injectors or the exhaust, Slick 50 is a great idea, IMHO.

Take care,
-Chris

 

i can vouch for that! i had a noisy lifter and i used slick50 when i changed my oil and it took care fo the problem.