Ticking noise with small amount of gas
 

I recently bought an 08 F150 supercab 4x4. Ran fine when I test drove it, listened for the tick and there wasn't one, but after about a month and a half of driving I noticed a slight ticking noise when I was cruising through town at about 40kmh. Took my foot off the pedal and it stopped. I then gave it just enough gas to maintain a steady speed and it came back. I put a bottle of STP octane booster in my tank the next time I filled up and it went away. I'm 19 and living on my own and I don't have a lot of spare cash so I'm hoping it's not something big; and considering the fact that it went away with just some fuel additive makes me think there's still time to save it from whatever it is that going wrong. The truck also has a slight shake at idle, but the RPMs don't drop when it happens. I've noticed the ticking is also more pronounce when the engine is warm. Sorry for such a long post, but I'm trying to give as much info as possible right from the start to help me solve this problem ASAP.

Fuel injectors can make a ticking noise as they open and close. If they get sticky the ticks can be more pronounced. Also this could account for your slight rough idle. The STP may have solved the gummy buildup on the injector. Drive it for a while and see if the tick returns. If it does try using SeaFoam fuel additive. It isn't as hard on the injector seals as STP, but it is about $10 a can. Good luck

im having the same exact problem with my 2008 4x4. Only taps when I am giving it a little gas, no tap at idle. I put STP octane booster in but it hasn't stopped the tapping. Did you try the sea foam?

Yeah that's what mine was doing. More of a "clack-clack" than a tick, only at like 1,000RPM and only when it was right up to temp. I tried the sea foam and it seemed to help it, but it came back after I filled up again. I just switched my oil to 15-40 and it's gone, probably just masked by the thicker oil but I haven't noticed any difference in how it drives or any new strange noises since switching, oil pressure seems good. So I'd say it's good, for now anyways. I heard of some people using 20-50 but I already had some of the 15-40 from my old truck lying around so I decided to use that.

You guys are probably experiencing the cam phaser noise. Its usually just the VCT solenoids that need to be replaced unless your oil pressure is actually too low (ford spec is anything below 15psi needs an engine). Get your engine warm, sitting stationary with it in gear and your foot on the brake rev it up between 1200 and 1500 RPM then release the gas pedal. If it starts to rattle like a clack-a-clack-a-clack-a or like the noise you're hearing its solenoids. If it rattles to the point where it dies or almost dies change the phasers too. To cgange the solenoids all you have to do is remove the valve covers and swap them out. While you're in there if you're at or past the 100000km (60000 mile) mark change your spark plugs, saves you time down the road since you'll have the coils out already.

Make sure your spark plugs are torqued to 25-27 lbs.

What do spark plugs have to do with it?