New Owner Learning Curve, Strange Sound

[Justin B]

Good afternoon folks,

So I've made a couple of recent posts about my new-to-me pickup. When looking the truck over at work with some folks I fired it up an someone pointed out a noise that I didn't hear when I bought it. There's a hollow sound coming from the exhaust, keeps rythym with the engine rpm. It sounds similar to an exhaust leak. Any places to start looking? I checked the torque on the manifold bolts since it was easy (all were sat), fired it up and listened more closely to try an pinpoint it. Standing up, I don't hear it noticeable in the engine bay, but when I crawled underneath it gets louder down below the oil pan. Obviously, the crossover pipe is right there but I'm unwilling to put my ear up to a hot exhaust pipe!

I assume it's coming from internally, but I'd like to pinpoint it before tearing the whole thing apart. I've read from other folks here it might be a bad valve or something other related to the valvetrain. I didn't do a compression test, but is that even viable at this point? I read a leak down test is the way to go to rule out valves an valve guides.. what do I need for this? Fittings an what not? Before I run out buying a bunch of fittings anyone know off hand the thread/pitch? I've got compressed air but kind of limited in specialty tools at the moment.. I'll invest in what I need to make this thing run right though.

I'm running out to pick up a supposedly running 6.9 tomorrow that I had intended on freshening up and keeping as a spare, hoping I don't need it sooner than later. I have other vehicles to get around so not pressed to drive her right now so I'll keep it parked until I get this worked out.

I realize there's numerous posts about strange noises, and I've been working on reading through them, just wanted to see if I could get any quick bites and figured anyone that offers help might be curious in how I progress.

Very respectfully,
Justin

 

[210Tumbleweed]

Harbor Fright....Automotive Stethoscope…..CHEAP but worth a pocket full of loose change, for diagnosing cklicks, clatters,and knocks.

 

[Golden Helmet]

Can you record a video and upload it to youtube so we can hear the noise? These IDI's have a ton of knocking sounds, most of them are normal but to a new guy it might sound like a rod is trying to escape.

 

[onetonjohn]

+1 for Automotive Stethoscope, but you can use a socket extension as well. Just put one end on what you want to listed to and the other up to you ear with your fist. Be careful there are no moving parts around that it can get caught on or hit (like the fan) - you don't want the extension being driven into you ear.

 

[saburai]

+1 for Automotive Stethoscope, but you can use a socket extension as well. Just put one end on what you want to listed to and the other up to you ear with your fist. Be careful there are no moving parts around that it can get caught on or hit (like the fan) - you don't want the extension being driven into you ear.

A long screwdriver Works in a pinch as well obviously, put the business and where you want to listen and the plastic handle in your ear.

 

[IDIBRONCO]

I'm not much help today. I have a couple of house cats so I always hear strange noises.

 

[Justin B]

I'll have to run it tomorrow, Mama's out of town and left me a honey-do list. I'll record a video best I can and poke around with an extension. Harbor Freight is about an hour from me. I was at Advance earlier for some other things and didn't see a stethoscope, anyone know where else I can pick one up? I know I can always order it, but I can be an impatient one when I set my mind to something.

 

[IDIBRONCO]

I believe that someone posted that you can get one at Advanced. It's about $10 instead of $3 or $4 at Harbor Freight, but for an hour's drive, I could spend the extra $6.

 

[Frstdiesel]

A length of heater hose works good too, plus it's flexible.
Put one end to your ear and probe around with the other end.

 

[Justin B]

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Just got home with the 6.9 and recorded a video of the stock motor running. I'm going to poke around in there and see if I can better pinpoint the location.

 

[Thewespaul]

Try loosing one injection line at a time and see if the sound changes

 

[Justin B]

So loosening one at a time didn't change the rythym of the chuff from what I could tell. I went through all 8, all fittings were snug, ears not tuned for exactly what I should be hearing, but the idle changes an sounds like a miss when each one is loosened, is that correct? I did get that.

 

[Thewespaul]

Well if the injector cutout test (loosing each injection line) didn’t change the sound, you can mostly rule out the nock to be injectors, if you want to try and find the nock before you replace the engine I would look under each valve cover first. Take pictures of each side post them here and make sure everything is tight

 

[Justin B]

The local stores have Mahle and Fel-Pro gaskets in stock, best ones to use for buttoning it back up? Should I rotate the engine through to get each piston to TDC and check valve clearance? Good time to do that leak down test if I'm getting into it that far as well?

 

[Justin B]

Nevermind of the valve clearance, just read that's not a thing for these motors.. lucked out twice on that one, my Harley has hydraulic lifters as well.

Not trying to put the cart before the horse here, but I was reading through some other threads and some guys experienced stuck lifters with similar sounds. Should I get some MMO or something similar to throw in as well?