Breaking down and asking for help

All,

Well as the title says hoping for some help. I have a engine tick (not a knock) or tapping that runs with the rpms. I have an 87 f250 with a 6.9. Roughly 171k on the odometer and an ats 088 turbo. After reading virtually every article on here with ticking/knocking I still can't figure out what it is.

-up and down engine with stethoscope, valve covers off and on
-The tick is only at idle to about 1100 or 1200 RPM, definitely quieter when cold but gets louder when warmed up. It is not obnoxiously loud.
-it is coming from around the #1 cylinder area.
-It developed after I replaced my mechanical fuel pump with an electronic. I did not fill my crank case with diesel. The mechanical arm fell off and I had to fish it out. The roll pin is still in the oil pan but I just can't see how that would create a problem.
-I use almost no oil
-it is not a glow plug tip.
-The truck runs absolutely fine
-There is not intake or exhausted woofing or chugging.
-It's not an accessory (took all the belts off, still there)
-Timed at 8.5
-If it's an exhausted leak I cant find any sign of it


Here is a list of what I replaced:

1) new injectors (I do not believe it is fuel related, I shut the truck off while coasting in gear and could still hear it)
2) new valve springs and seals (literally every valve guide was tight - not ruling this out but no play)
3) new lifters, push rods, and rockers
4) replaced exhaust manifold gaskets

Only thing I can think left is broken ring, cracked piston, piston slapping, somehow the inj pump creating a weird injector pop timing or maybe air intrusion somehow? Any other ideas? I am at a complete loss.

I have a similar tick.

One question first Where is your fuel pump mounted?

My Duralift ticks when is pumping fuel. I have a shut off switch on the dash and found out that I can hear it while driving, but there is another tick that I cannot control...

IMO - If the tick changes under a load (slip the clutch while holding the break a bit) then it could be piston slap or wrist pin slap

Im sure more educated people will chime in

Good luck!

Thank you all for the replies/suggestions. For my fuel pump I have it mounted way back at the rear tank (I pulled the mid tank).

I have to think that it is mechanical at this point and somewhere internal. I'm not going to pulled the heads to fix it, I'll end up driving it until it implodes or whatever and I'll put in a rebuilt motor.

At this point it is more of a challenge hahaha I don't want to give up trying to figure it out.

I'm going to say it's probably piston slap as well... Bearings getting worn.

One thought: Try throwing in a quart of Lucas Oil Stabilizer. It should definitely quiet it down a bit.
The tolerances on these engines mean that it won't do anything bad(I've run 50% lucas for a couple thousand miles and the engine was still running when I pulled it)

Is it loud enough to get a video of it? I've tried to get a video of mine but the mic can never pickup the specific ticking.

Regarding the additive I have done a few different oil changes with additives (run about 100 miles and think I've found the next cure) and they absolutely quiet it down but not for long.

Yeah, I will get a video of it. I don't know why I didn't think to do that when posting this. It should be enough to pick up on video.

Does something like piston slapping just develop? That's why this has got me baffled, wasn't there and then like the next day it was. I'm guessing I put maybe 10 miles on it between no sound and sound. I guess it may have been there I just couldn't hear it.

Sorry for the dark video, but it is taken standing in front of the truck.

That sounds like an exhaust leak to me.

Either that, or check that you don't have a bent pushrod.

I agree it sounds exactly like an exhaust leak but I couldn't find any cracks in my manifold (wire wheeled it) and one of those new super thick expanding exhausted manifold gaskets. Maybe the crack is so small it develops more when warm, hence the noise increase when warm. I threw a straight edge on the manifold and it didn't appear warped or anything. The manifolds are cheap new so I might try it and a new gasket and see what I get.

I'll bet something to do with a pushrod or lifter. Valve isn't opening quite right.

I thought that as well, exhaust leak or lifter/push rods. But I replaced all the pushrods, lifters, valve springs, and rockers. So that would mean the valve isn't sitting right or worn guides? I definitely checked for play on the guides when I pulled the springs off and I couldn't feel any movement (whether the valve was seated or unseated).

Check the exhaust from the manifold to the up pipe, and I guess there's a joint in the up-pipe?

I know that when my crossover pipe cracked, it sounded similar...

Good call. I wanted to pull it out again to wrap it so I'll try some sealant on that joint as well. I know the acoustics can get bouncing around but by my calibrated ear it is coming at the exhaust manifold level at the front corner of the engine. I threw my scope on it and I couldnt hear anything. I sure wish I was Sherlock Holmes.