thoughts on noise

[ellis93]

Noise comes in at about 21 or 2200rpm. Its a light tap,about the same noise as a loose rocker arm. Its not the valve lash, ran them twice and its still there The noise has been there for about a year,it has not gotten worse and sound exactly the same as when it started.

Question is what's the chance that an injector is making it?
Don't really know if I'm reaching on this but everything else has been gone thru. Valve lash,fuel pump,valve lash again,checked for loose and rattling brackets......

[ellis93]

Clutch disc damper springs? They shouldn't be loose under load, should they?

[ahale2772]

did you take a gander at all the valve stem heights when you adjusted them? could be something f'ed up with one of the rocker ball seats or even a valve seat.

its a continuous, varying-with-rpm type noise correct?

[ellis93]

Yes it carries the rhythm of the motor after 2100rpms and only then. No other time. I'm hoping its not valve,guide,or spring related but...... As far as the "look" of things, it all looked good to me. I didn't see any wear.

[ahale2772]

and it carries the noise under load?

[ellis93]

Yep. Every time rain or shine. Been driving me crazy. The trucks fixin to be downed for the trans and I wanted to get some ideas about this. I'll check those valves out again.

[ahale2772]

its probably your cam, actually, im 100% sure its do to insufficient lift and duration of your stock cam.

[ellis93]

Chit, you really think so....I'm PMing BC now

[ellis93]

Found something else out this afternoon, that noise goes away above 2600 rpm I really never run my hard but today I took some logs off to be sawed up that I had floating in my mom's pond. Those dang things were HEAVY! They made me have to run the old man up a few more 100rpm before shifting and that's when I noticed the tone change.

Anyone have an opinion about it? Well....a constructive opinion

[142autox]

Nothing really constuctive here, but I have a similar noise. I haven't check my valve lash though. I'm doing the KDP this weekend everything else comes after. Mine doesn't do it free reving but I can faintly hear it while driving. Piston slap??? I really don't know but let me know what you find out.

[chrislib]

I have a very similar noise,sounds like one single rocker arm tapping away but I cant narrow down the rpm as I dont have a tach. I think might be injector related as it seems to vary intensity with engine load/timing. I`m going to try running with the ksb disconnected and then hot wired to see if it changes anything.

[92strokersmoker]

My truck also has a tapping noise around 2100-2600 rpms. You can hear it mostly if you run 3rd gear up to like say...2300 then let out of the pedal and taps away. This is only while in gear so Its making me wonder if its not a trans or clutch related noise. If I down shift from 5 to 4 I can also hear it but as soon as I clutch it goes away. Even in neutral , If i run up to 3k I cant hear diddly. This is why Im wondering if its clutch or trans. I think Ill check the valve train anyway this week in shop

[ellis93]

I hope you have better luck than I, I've ran mine plenty and the noise is still there. I'm going forth with new(or different)injectors. That's gotta be my problem

[1arock]

Does it have to be moving to make this noise? Try taking the belt off and reving it up to eliminate the accessories such as the alternator and pumps. I had an alternator once that made a noise that most folks thought was a death rattle. It's worth a try. Rocky

[92strokersmoker]

Update on my noise:

Crawled under truck and had my head near bellhousing and oil pan. Amongst the loud engine noise I could pick up a tapping at the back of the engine, all I can think of is a wrist pin or thrust bearing. I may be hearing some # piston slap . You cant hear it in the engine bay even toward the back, only around the pan. One other thing I could think of is last year when I did my rear main, I pulled the trans and my pilot bushing was thrashed into pieces and I wonder maybe this ones junked and my input shaft is walkin a little bit inside the flywheel. ....:confused: