My truck has started a light tick when you are accelerating right around the 2500 rpm mark. Even if you have it in neutral and rev the engine you can hear a ticking sound around this mark. I am not exactly sure if it is a spark knock or coming from something else. I have the hughes kit installed in the plenum and it passed the vacuum test, and there is only a light amount of oil residue in the bottom of the intake (no puddles). The area where the plenum pan meets the intake looks a little wet (in the gasket area) but there are no puddles in the bottom. My truck has good power, but the gas mileage has got a little worse lately along with the tick. I thought for sure the plenum was acting up, but now I am not sure. I may tear it down when the weather gets a little warmer and double check everything. I am running the Superchips but I reset the truck to stock and am still hearing the same tick (and this is with running 93 octane). Mine could possible be an exhaust leak starting, I just don't know!

 

I would say it's definitely not pinging if you're on the stock tune with 93 octane. It could be an exhaust leak, but if you're running the stock manifolds I'd say no.

Do you ever hear it anywhere else? Perhaps a pulley is going out.

 

Could be either a lifter or an injector. My truck "ticks" from time to time, and it's one of those. I'm leaning toward it being a lifter.

 

i am also thinking lifter.

 

If I put truck in low 2 and drive it with the rpm's around 2500 rpm you can hear it the best. I noticed too that you can hear it when you are lightly accelerating but not giving it a lot of gas (I have the noisy 14" air cleaner on it!). I got on it going up a hill yeterday and didn't hear any spark knock, but you when I let up on the accelerator just before it shifts you can hear it pretty good. It kind of hangs in gear for a couple of seconds (tv cable set a little tight) and you can hear the sound. It's kind of like a sewing machine sound. It's not very loud, its about as loud as a small spark knock. Also, at idle there is no ticking sound and when you have the hood up holding the accelerator you can't hear it. I may try the Marvell Mystery oil and see if that helps. I ran a can of Seafoam thru the brake booster line into the intake Saturday and also put a can in the fuel tank, so it may clear itself up as I drive it.

 

One thing to try: use a thicker oil next time you change it. Maybe 10W-40 instead of 10W-30 and see if the lifter quiets down.

 

Will do, thanks!!

 

I put some Marvel Mystery Oil in the crankcase and the noise is still there. It doesn't really sound like a stuck lifter it sounds more like a valve rattle. I noticed today that if you just rev the engine (without a load on the engine) you can hear it. It is not like a normal spark knock where you hear it while under load. It actually starts before the 2500 rpm mark, but it is the loudest at that point. If I reset my SC to the stock setting should the rattle go away instantly (I am running 93 octane) or does the computer have to relearn the stock settings? One other thing that just came to memory, the other day I pulled the Autolite 3923's and put in NGK plugs. Before I changed the plugs I started the truck on moved it to my carport and so the truck only ran for a about a minute or less. When I pulled one of the plugs it actually had gas on it. The plugs looked clean with the exception of that plug having raw gas on it. It wasn't a lot, just mainly in the first couple of threads of the plug. The plug tip looked clean though. It may have been where the engine was cold, I don't know.

 

Here is a picture of the 3923 plugs that came out of the truck. They only have a couple hundred miles on them. The plug tips are pretty clean but there is carbon on the top of the thread area on all the plugs (see arrow)

 

I set the computer back to stock and then reset the computer and the sound is still there. So, it's probably not spark knock or valve rattle since I am running 93 octane gas?

I recently put new cap, rotor button and plug wires (following the proper routing procedure) I used the summit racing brand wires and cap.

I have added a timing chain tensioner to my double roller timing chain last spring (due to the chain making a knocking noise at idle which went away after adding the tensioner), but I don't think that would cause this.

The valve timing is set to two degrees advanced, but I did that last spring as well. It was advanced 4 degrees before that, and never pinged.

The noise accelerates with the engine.

Has anyone had a tensioner on the serpentine belt to make any noise?

What about a sticky injector? What are the symtoms of that?